Throttle Body "MORE" cracked cable cams/pulleys

[dirtrider]

Well, we have some more!\

 

I have been kind of catching up on some bikes that I service from time to time for a couple of relatives, riders in my group,  friends, etc. 

 

Out of (4) 1200RT's that I have worked on so far this spring (3) had cracked TB plastic cams, one bike was only cracked on the L/H side  with a small (but all the way across) crack (above idle balance was still good),   the other was  severely cracked on both sides (this bike also showed an off-set in above-idle (part throttle) cross side balance since it was last done. The 3rd bike is MINE, both sides show cracked this spring (it was OK last spring).  I didn't do a pre-inspection balance check on my own bike as I will do that prior to cam/throttle shaft replacement.   

 

One bike was an 07, one was an 08, & 2 were 09's The 07 was the non-failure bike.

 

I started checking plastic throttle body cable cams for cracks on all 1200RT's that I work on for a TB balance or other (Tupperware removal reasons).   

 

-- 1200RT owners should probably start checking your TB cams at least once a year, OR, if you see a change in above idle cross side balance. (or ask your dealer to do it if they service your bike)

 

 If careful you can slide the plastic  covers up the throttle cables then use a small dental mirror (or small mechanics mirror) & a strong light to inspect the TB cable cam centers (at least see enough to make an assessment as to removing the TB's for a closer inspection).  The cable cams are on the back side  (engine side) of the throttle bodies).

 

Maybe we should start a dedicated (permanent)  thread  with an ongoing list  just for 'cracked TB cams' so we can add bikes by model year & miles to that list as we find them.

 

It might be productive to have an ongoing failure list to link to when we file a NHTSA report.

[LBump]

I'll have to be checking mine... Thanks for the observation. 

[Ponch]

9 hours ago, dirtrider said:

Well, we have some more!\

 

I have been kind of catching up on some bikes that I service from time to time for a couple of relatives, riders in my group,  friends, etc. 

 

Out of (4) 1200RT's that I have worked on so far this spring (3) had cracked TB plastic cams, one bike was only cracked on the L/H side  with a small (but all the way across) crack (above idle balance was still good),   the other was  severely cracked on both sides (this bike also showed an off-set in above-idle (part throttle) cross side balance since it was last done. The 3rd bike is MINE, both sides show cracked this spring (it was OK last spring).  I didn't do a pre-inspection balance check on my own bike as I will do that prior to cam/throttle shaft replacement.   

 

One bike was an 07, one was an 08, & 2 were 09's The 07 was the non-failure bike.

 

I started checking plastic throttle body cable cams for cracks on all 1200RT's that I work on for a TB balance or other (Tupperware removal reasons).   

 

-- 1200RT owners should probably start checking your TB cams at least once a year, OR, if you see a change in above idle cross side balance. (or ask your dealer to do it if they service your bike)

 

 If careful you can slide the plastic  covers up the throttle cables then use a small dental mirror (or small mechanics mirror) & a strong light to inspect the TB cable cam centers (at least see enough to make an assessment as to removing the TB's for a closer inspection).  The cable cams are on the back side  (engine side) of the throttle bodies).

 

Maybe we should start a dedicated (permanent)  thread  with an ongoing list  just for 'cracked TB cams' so we can add bikes by model year & miles to that list as we find them.

 

It might be productive to have an ongoing failure list to link to when we file a NHTSA report.

 

Amen brother. 

[greiffster]

 

DR,

Here's a shot of my left side.  I assume you are speaking of the radial crack at about 8:00 o'clock??  From a side view it appears to go all the way through.

 

Update...the right side is cracked as well in the same fashion (see photo below).  If you look dead straight on, you can see the metal through the crack, but it has very little separation.

 

[dirtrider]

17 hours ago, greiffster said:

 

 

DR,

Here's a shot of my left side.  I assume you are speaking of the radial crack at about 8:00 o'clock??  From a side view it appears to go all the way through.

 

Update...the right side is cracked as well in the same fashion.  If you look dead straight on, you can see the metal through the crack, but it has very little separation.  I couldn't get a good picture of the right side.

 

 

 

 

 

Afternoon greiffster

 

That is the crack (cracks) that we are talking about. Problem is, that is just the front side, there is no way to easily tell if the backside is also cracked. A crack on both the front side & rear side is getting to the fatal point as the design has a built in wedging effect.  

 

That plastic cam is molded around (surrounds) the  center metal arm piece on both sides  with 3 notches in the metal piece to keep the cam in position & to keep it from spinning on the metal arm.

 

It's those 3 notches that cause the issues as once a crack appears those notches apply a sizable splitting force to the plastic cam & actually force the plastic cam hub apart so that continually forces the cracking to enlarge to the point of full failure.

 

I have seen enough of these cracks now to say  that your bike is still ridable within easy recovery range of your home base. That cam (crack)  shown might last a long time or a short time but 'IT WILL' fail eventually (hopefully not 3 states away in the middle of the night in the L/H lane of a 4 lane hi-way).

 

You have some choices--- ride it locally until failure (at that point you are forced to repair it), install the Beemer Bits (very expensive) alloy replacement cams, install new OEM cams-only from BING, install new cams with shafts attached from Bing ($128.00 for L/H & R/H shipped to your door), or install new throttle bodies (over $1000.00 for both sides). 

 

The actual throttle body removal is fairly straight forward (IF) you have proper clamp ring removal pliers. The new Bing shaft with cam is not a difficult install (if all is marked & care is used in getting it back aligned properly).

 

The difficult part is in how to check/get the base idle  screws set back close to specs-- There is no BMW documentation on how to do this  as BMW only services the entire throttle body. I have my own procedure that 'seems' to work OK but there is no positive way to actually verify that the procedure that I use is accurate enough to get them back to OEM spec. So far the couple that I have done are running good without runability issues or idle issues.

 

I have 3 more to do in the coming weeks though --

 

Oh, by the way, welcome to the 'crack club'!  

 

 

 

 

 

[greiffster]

10 minutes ago, dirtrider said:

Oh, by the way, welcome to the 'crack club'!  

 

 

Swell.  I just became a member of the "fuel strip club" last week....

 

Can you point me to a link from Bing on the correct part?  It seems you might be suggesting the "cams with shafts attached from Bing" for $128.  I've got a trip coming up to Canada, and I'd rather not worry about it.  Also, any tips on bs'ing the base idle screws would be great.  As always, thanks for the help DR!!!! 

[dirtrider]

16 hours ago, greiffster said:

 

Swell.  I just became a member of the "fuel strip club" last week....

 

Can you point me to a link from Bing on the correct part?  It seems you might be suggesting the "cams with shafts attached from Bing" for $128.  I've got a trip coming up to Canada, and I'd rather not worry about it.  Also, any tips on bs'ing the base idle screws would be great.  As always, thanks for the help DR!!!! 

 

Afternoon greiffster

 

I haven't done a GS yet so verify that you have Type 77 throttle bodies (it will say on the lower casting)

 

 http://bingcarburetor.com/store/p134/Type_77_Throttle_Body_Pulley_%26_Shaft_Assembly.html

 

I haven't done any in a while so hopefully the Bing picture shows the plastic might be thicker in the outer hub area than the OEM  were. (might just be hopeful viewing though).

 

I'm dong the shafts/cams on my personal 1200 as well a riding friends 1200. On the other bike, that I just found bad, the guy lives in another location (far from me) so he is leaning towards the easier to install & non-base-screw-effecting Beemer Bits alloy cams (bunch of bucks but the easy way out for him).

 

Do you have a GS-911 that you can use?

[greiffster]

13 minutes ago, dirtrider said:

 

Afternoon greiffster

 

I haven't done a GS yet so verify that you have Type 77 throttle bodies (it will say on the lower casting)

 

 http://bingcarburetor.com/store/p134/Type_77_Throttle_Body_Pulley_%26_Shaft_Assembly.html

 

I haven't done any in a while so hopefully the Bing picture shows the plastic might be thicker in the outer hub area than the OEM  were. (might just be hopeful viewing though).

 

I'm dong the shafts/cams on my personal 1200 as well a riding friends 1200. On the other bike I just found bad the guy lives in another location (far from me) so he is leaning towards the easier to install & non-base-screw-effecting Beemer Bits alloy cams (bunch of bucks but the easy way out for him).

 

Do you have a GS-911 that you can use?

 

Yes, I have a GS-911.  What do I have here??

 

[dirtrider]

3 minutes ago, greiffster said:

 

 

Afternoon Mike

 

Not easy but look on the other side of that lower flange (should be just on the back (opposite) side of the BING you show in picture.

 

aggieengineer   just had a thread on the Beemer Bits cams a couple of days ago.

 

https://www.bmwsporttouring.com/topic/91801-throttle-body-pulley-repair/

 

 

 

 

[greiffster]

5 minutes ago, dirtrider said:

 

Afternoon Mike

 

Not easy but look on the other side of that lower flange (should be just on the back (opposite) side of the BING you show in picture.

 

 

 

It reads BING 771

[dirtrider]

2 minutes ago, greiffster said:

 

It reads BING 771

 

Afternoon Mike

 

The last one that I did had 77/ not 771--might be a good idea to call Bing just to be sure--  (number should be on the site that goes with that link I posted). The Bing USA is pretty friendly & helpful. 

[greiffster]

7 minutes ago, dirtrider said:

 

Afternoon Mike

 

The last one that I did had 77/ not 771--might be a good idea to call Bing just to be sure--  (number should be on the site that goes with that link I posted). The Bing USA is pretty friendly & helpful. 

 

It's 77/.....I just looked again.  I thought it was a 1 when looking at a mirror image.

[dirtrider]

Just now, greiffster said:

 

Its 77/.....I just looked again.  I though it was a 1 when looking at a mirror image.

 

Afternoon Mike

 

You have a GS-A correct? If so then I do still suggest that you call Bing just to verify (should work but I have no background to confirm that).

[greiffster]

12 minutes ago, dirtrider said:

 

Afternoon Mike

 

You have a GS-A correct? If so then I do still suggest that you call Bing just to verify (should work but I have no background to confirm that).

 

Yes.  Confirmed with BING.  Upon closer inspection, I have the 77/47.  (the 47 was not well etched).  Apparently there were a few built with 77/50  (with some kind of different cable end)

[greiffster]

Also, the tech guy from BING suggested maybe just the pulleys for $20.  Is that not easier?

[dirtrider]

13 hours ago, greiffster said:

 

Yes.  Confirmed with BING.  Upon closer inspection, I have the 77/47.  (the 47 was not well etched).  Apparently there were a few built with 77/50  (with some kind of different cable end)

 

Afternoon Mike

 

My 09 1200RT also shows 77/47 (with the 47 being very lightly stamped & difficult to see)

 

Then you need to decide if you want to go with the unknown of trying to verify that the new shafts/cams will have a proper base idle screw setting (very fiddly & subjective), or install the more expensive Beemer Bits alloy cams, or remove & send your TB's to Bing for cam or cam/shaft installation (I'm not sure how they set/verify the base idle screw settings)-- this question needs to be asked.

[dirtrider]

11 minutes ago, greiffster said:

Also, the tech guy from BING suggested maybe just the pulleys for $20.  Is that not easier?

 

Afternoon Mike

 

I don't know about easier, I haven't done that. The base idle screw problem still exists as the new (cams-only) come molded on a new idle stop/spring lever so you could still have the same base idle screw setting problem. (depends on how accurate the Bing parts are made & how much the part making machines are worn/changed since your OEM parts were made/installed/adjusted)

 

I have looked at just the cams (only) couple of times (they are pressed on the shafts)  so I had a couple of ideas on how I could possibly install the cams with the shafts still in the TB's. So far all that I have read about  people installing 'just' the cams they had to remove the shaft/cam from the throttle body to press the cam off/on the shaft  so I didn't see much gain in doing JUST cams other than a few dollar savings & lot more work. (if you bend a shaft during cam press on, even a little, then you REALLY have idle setting issues).    

[greiffster]

 

So, looking at this shot of just the pulleys...and assuming you can get the old ones off...

 

Is there some way to "measure" the distance of the stop of the old cam based on the rotation of the squared off edge as it is mounted to the shaft.  So that you can duplicate this distance (or verify it is the same) on the new one?

[dirtrider]

8 minutes ago, greiffster said:

 

So, looking at this shot of just the pulleys...and assuming you can get the old ones off...

 

Is there some way to "measure" the distance of the stop of the old cam based on the rotation of the squared off edge as it is mounted to the shaft.  So that you can duplicate this distance (or verify it is the same) on the new one?

 

Afternoon Mike

 

Yes, there are some ways to make the measurement, BUT! that doesn't mean that the cam will press on in perfect alignment.

 

Personally I would put "O" confidence in using any measurement from the center hole to stop contact area as a controller to get the idle stop set correctly due to the distance of the center hole flats to the actual stop area.   

 

Installing JUST the cams would not gain anything over installing shafts/cams as far as the idle stop confirmation goes.

[greiffster]

30 minutes ago, dirtrider said:

 

Afternoon Mike

 

Yes, there are some ways to make the measurement, BUT! that doesn't mean that the cam will press on in perfect alignment.

 

Personally I would put "O" confidence in using any measurement from the center hole to stop contact area as a controller to get the idle stop set correctly due to the distance of the center hole flats to the actual stop area.   

 

Installing JUST the cams would not gain anything over installing shafts/cams as far as the idle stop confirmation goes.

 

Makes sense.  I'm going to order the cams with the shafts and hope I don't screw it up too bad.

[dirtrider]

14 hours ago, greiffster said:

 

Makes sense.  I'm going to order the cams with the shafts and hope I don't screw it up too bad.

 

Evening Mike

 

It's definitely doable at home, maybe not perfect  but who knows how close the factory adjustment was.

 

Do not take anything apart, throttle body wise, without marking, measuring, & taking pictures.

 

Here is a picture of the last one I did a while back, this is what/how I marked the throttle plate to shaft before removing the throttle plate. I also took this picture so I could get the plate back in the same orientation (note number 5 position in bore).

 

I also measure (try to anyhow)  the closed throttle plate to bore clearance with original stop arm resting on the factory adjusted stop screw.

 

I also hold the throttle body, with a closed throttle plate, up to a strong light  while looking through the throttle bore--that should show a very slight thin ring of light around the OD of the throttle plate ( this light ring should be remembered & etched in your memory as you need the same small ring of light showing around the throttle plate after new shaft install). 

 

Last one that I did I used my etched lines on the throttle plate to align the throttle plate clocking orientation then used a couple of lengths of .001" shim stock on each side of the closed throttle plate to hold/force plate centering while snugging down the screws.

 

If you have a GS-911 then get the bike running 'riding hot', then after a short curb idle period (to allow curb idle to stabilize) use the GS-911 to capture hot engine, stabilized (GS-911 held) idle stepper counts (put this in an Excel file or write the numbers down). --Then during the same hot curb idle period check & record the idle cross side balance & write the difference down. (do all this BEFORE taking the TB's off & apart)   

 

The next shaft/cam install that I do (coming up shortly) I think I am also going to do a pre-disassembly base idle screw position check to a fully closed throttle plate. ie, precision mark the base idle screw at the factory pre-set position, then see how far I need to back it up to get a fully closed throttle plate. (THIS is a fall-back 'if everything else goes wrong' appx usable setting). So, if I have to back the screw up 1/4 turn to get a fully closed throttle plate then if all else fails I s-h-o-u-l-d  be able to start with a fully closed throttle plate then run the screw in 1/4 turn & be close to the factory setting)

 

Next, ONLY do one side at a time so you can use the good (factory side) to match the repaired side to on idle stepper counts & hot engine idle cross  side balance.

 

   

   

[greiffster]

DR, Thanks for the tips!!  I'll report back.

[Indy Dave]

Oh my aching head . .

[Indy Dave]

On 4/30/2019 at 12:00 PM, dirtrider said:

 

I started checking plastic throttle body cable cams for cracks on all 1200RT's that I work on for a TB balance or other (Tupperware removal reasons).   

 

-- 1200RT owners should probably start checking your TB cams at least once a year, OR, if you see a change in above idle cross side balance. (or ask your dealer to do it if they service your bike)

 

 If careful you can slide the plastic  covers up the throttle cables then use a small dental mirror (or small mechanics mirror) & a strong light to inspect the TB cable cam centers (at least see enough to make an assessment as to removing the TB's for a closer inspection).  The cable cams are on the back side  (engine side) of the throttle bodies).

 

 

 

Given my tendency to look for a needle in a haystack, only to get snared by a bear trap - Mike or DR, can you provide a wider view (photo) of where I need to be digging to get my fix of crack?

[greiffster]

45 minutes ago, Indy Dave said:

 

Given my tendency to look for a needle in a haystack, only to get snared by a bear trap - Mike or DR, can you provide a wider view (photo) of where I need to be digging to get my fix of crack?

 

Dave,

Between the throttle body and engine, on each side, you'll find the suspect cam.  Just follow the throttle cable to the adjustment nut coming on top of the plastic half cover over the throttle cam.  You can simply slide the half cover straight up a couple of inches.  Now lay on your back and look from underneath with a good light and adjustable inspection mirror.

 

edit:  You may have to pop off the plastic base idle adjustment screw cap as it kind of gets in the way of the cover.  You can just barely see it in the second picture to the left.

[dirtrider]

1 hour ago, Indy Dave said:

 

Given my tendency to look for a needle in a haystack, only to get snared by a bear trap - Mike or DR, can you provide a wider view (photo) of where I need to be digging to get my fix of crack?

 

Afternoon Dave

 

Mike gave you the how to get there (after you remove the basic Tupperware)

 

This picture would be looking at the throttle body cable cam area as if you were viewing from  engine case side of the throttle body. It just basically shows how the plastic cover slides up the cable (with a little wiggling/twisting/turning to clear things) 

 

Caution: don't put a lot of side force on the throttle cable as it is not difficult to break the cable adjustment fitting  at the thin area just above the adjustment lock nut.

 

[Ponch]

These were mine

[greiffster]

This whole thread has got me thinking more of this base idle adjustment screw.  Why doesn't BMW just share or publish the frickin' OEM/factory method for setting this screw?  Why is this some kind of secret?  Do the dealers even know?  Or is their only solution ordering a new TB from the factory, already set?

 

Surely, BMW knows they have a weak part in the plastic TB cam.  Heck, we have several threads on the issue.  They could help mitigate the problem by offering up a factory solution passed on to the dealer, that doesn't require $1200 parts.

[dirtrider]

31 minutes ago, greiffster said:

This whole thread has got me thinking more of this base idle adjustment screw.  Why doesn't BMW just share or publish the frickin' OEM method for setting this screw?  Why is this some kind of secret?  Do the dealers even know?  Or is their only solution ordering a new TB from the factory, already set?

 

Surely, BMW knows they have a weak part in the plastic TB cam.  Heck, we have several threads on the issue.  They could help mitigate the problem by offering up a factory solution passed on to the dealer, that doesn't require $1200 parts.

 

 

Evening Mike

 

Probably because BMW doesn't possess or even know the correct method of setting those screws. That base idle screw setting is done at Bing then BMW buys the  entire throttle body from Bing ready to go on the engine.   

 

I'm not sure how Bing initially  sets those screws at initial throttle body assembly. It might be using an air flow bench, or air flow device, or possibly just using a special calibrated inclinometer type device.

 

The dealers definitely don't have a clue  as they either replace the entire throttle body (that is the BMW suggested repair) or some progressive dealers will send the throttle body out to Bing USA or to Beemer Bits. (this in on the individual dealer not from BMW)

 

BMW MUST know they have a problem in that area (if nothing else due to accelerated throttle body sales) but typical BMW is to not acknowledge  any problem areas unless forced to, then they have a way of delaying addressing  the problem until it is past the  recall period.

 

BMW will do nothing with this problem until forced to but even then it would be a very expensive to call back & repair all the problem bikes so  my guess would be some sort of band aid applied to cracking cams. Like  band or crimp on cap sort of a deal) --Then only address the ones that actually fail in use (like the fuel pump pass through fitting cracking issue).

 

My guess is (based on past BMW commitment to these sort of problems)  is that we could eventually  see some sort of cheap fix to band-aid the problem.

 

I have something I will publish in a short while   (as soon as I do some testing & verification) but I t-h-i-n-k  I might have a way to check/set that base idle screw (very close anyhow)   using common feeler stock & a basic simple procedure. (it's been repeatable on a couple of TB's on my bench but I haven't tested on a running engine yet).

 

I am going to do my personal 1200RT this way to see how it works out, then ride it a short while, then use pre-repair GS-911 trapped data to verify the accuracy of this method.

[aggieengineer]

3 minutes ago, dirtrider said:

I have something I will publish in a short while   (as soon as do some testing & verification) but I t-h-i-n-k  I might have a way to check/set that base idle screw (very close anyhow)   using common feeler stock & a basic simple procedure. (it's been repeatable on a couple of TB's on my bench but I haven't tested on a running engine yet).

 

That would be a major step in increasing our independence from the manufacturer-dealer network for this problem. Honestly, I'd be surprised to see any hexheads not affected at some point. The option to replace the pulley/shaft combination would save riders considerable money if it could be done without creating problems with air delivery. Very much looking forward to seeing more!

[dirtrider]

52 minutes ago, aggieengineer said:

 

That would be a major step in increasing our independence from the manufacturer-dealer network for this problem. Honestly, I'd be surprised to see any hexheads not affected at some point. The option to replace the pulley/shaft combination would save riders considerable money if it could be done without creating problems with air delivery. Very much looking forward to seeing more!

 

Evening aggieengineer

 

Not only hexheads but I have seen some reports of camheads having the same issue so it seems to be expanding across another model year series.   

 

At the moment  I am somewhat confident that it will work on low mileage (low wear) throttle bodies with unmolested factory set base idle screws.  I'm a little skeptical of the process being accurate on worn high mile throttle bodies or if the original factory setting has been disturbed.  It might work or might not work on disturbed base idle screws  depending on IF I  (we all) come up with a basic generic setting that works  across all throttle bodies. Right now the process is based on pre-measuring the factory setting then reproducing that on the after-repair throttle body. If all (or most) of the  pre-repair measurements come out close to the same then we could probably use them as a given on the molested screw units.      (lots to learn on this one yet).

 

As soon as I verify that the process works (on my own bike) I will put the pictures & process up here then open it to discussion, refinement, suggestions, more input, etc).  

 

I do have a complicated (GS-911) based process that has worked OK so far but it is complicated, fussy, very time consuming, & the person doing the work must really understand how to get consistent & accurate GS-911 data that they fully  trust.  (this process is definitely not for most do-it-yourselfers).     

[Ponch]

27 minutes ago, dirtrider said:

 

 

Evening Mike

 

 

 

BMW MUST know they have a problem in that area (if nothing else due to accelerated throttle body sales) but typical BMW is to not acknowledge  any problem areas unless forced to, then they have a way of delaying addressing  the problem until it is past the  recall period.

 

BMW will do nothing with this problem until forced to but even then it would be a very expensive to call back & repair all the problem bikes so  my guess would be some sort of band aid applied to cracking cams. Like  band or crimp on cap sort of a deal) --Then only address the ones that actually fail in use (like the fuel pump pass through fitting cracking issue).

 

My guess is (based on past BMW commitment to these sort of problems)  is that we could eventually  see some sort of cheap fix to band-aid the problem.

 

 

 

 

Don't Eilenberger said this about the fuel leak problem:

 

 

"I'm betting BMW's solution will be some sort of clamp on ring, with a special tool to install it (probably an Oetker type design) allowing the dealer 30 minutes labor time to do the job (regardless of bike model..)

 

And I'm sure based on BMW's usual reactions to these sort of things:

 

1. What problem?

2. Oh, that problem. First we've heard of it.

3. You caused it

4. Your environment caused it (fuel properties usually)

5. We have no problem

 

Is at step #4 now... so I'm certain they've never heard of the problem in Europe.. (said with tongue firmly in cheek..) It's caused by bad US karma."

[greiffster]

40 minutes ago, dirtrider said:

 

Evening aggieengineer

 

Not only hexheads but I have seen some reports of camheads having the same issue so it seems to be expanding across another model year series.   

 

 

 

I'm assuming the camheads have the same throttle body?  This failure sure seems like a heat/time/plastic oxidizing problem, no?  So, yeah the camheads will probably start crumbling soon as the plastic becomes more brittle. Unless Bing recognized the problem early on and started using a different plastic?

 

Which leads to another question...  Are the new cam/shaft units from Bing made of the same material and thickness?  And should we expect about 10 years out of those before they fail?  Of course by then, the hexheads will be relics.

[Ponch]

1 minute ago, greiffster said:

 

I'm assuming the camheads have the same throttle body?  This failure sure seems like a heat/time/plastic oxidizing problem, no?  So, yeah the camheads will probably start crumbling soon as the plastic becomes more brittle. Unless Bing recognized the problem early on and started using a different plastic?

 

Which leads to another question...  Are the new cam/shaft units from Bing made of the same material and thickness?  And should we expect about 10 years out of those before they fail?  Of course by then, the hexheads will be relics.

 

I got 5 out of mine, but I live in AZ now. I imagine it's worse in hot climes.  Plastic is just the wrong material, but BMW uses it extensively where metal could or would be used and it leads to failure. I've read that their cars use it for coolant lines and in one case it's under the intake and when it goes, a lot has to come apart. I really don't understand this kind of engineering thinking from a manufacturer high end machines.  I guess one has to be a true believer. 

[dirtrider]

14 hours ago, greiffster said:

 

I'm assuming the camheads have the same throttle body?  This failure sure seems like a heat/time/plastic oxidizing problem, no?  So, yeah the camheads will probably start crumbling soon as the plastic becomes more brittle. Unless Bing recognized the problem early on and started using a different plastic?

 

Which leads to another question...  Are the new cam/shaft units from Bing made of the same material and thickness?  And should we expect about 10 years out of those before they fail?  Of course by then, the hexheads will be relics.

 

 

Evening Mike

 

I have no idea, I really don't see them changing the material as their injection process & dies were set up for what they were designed to run. The plastic on my current (cracked) cams is POM (polyoxymethylene) & the pictures of the new cams on the Bing site are also labeled <POM> for European recycle requirements.  (I have some new shafts/cams coming so I will see what they are labeled).

 

Now on the thickness, I am hoping that some slight modifications in the thickness, or possibly a bonding change might have been made.

 

What I would really like to see instead of those darn notches in the stop arm is possibly some round or oval holes  (there is one round one already) as that might prevent the wedging action as well as keep the plastic intact instead of expanding then cracking & splitting. 

 

Or maybe a tight fitting outer cap that rolls down over the outer edge of the cam hub with a center screw into the shaft holding that cap on tight (think of a very thin freeze plug) .  It would have to be  pretty thin  or that secondary return spring will contact it as it crosses over that area at full open throttle. 

 

As for design change or thickness increase-- I have a couple of sets of shafts/cams on the way right now so I will compare to the originals when they get here.

 

I would also like to know if the failure rate  is the same on non cruise control bikes as my cruise control can put a LOT of pull on those cams climbing a steep hill in 6th gear with a load on the bike. 

[longjohn]

I'll add my 2¢ here:  My '05 was running poorly with lots of hesitation about 5yrs ago, and the dealer said both of the cams were cracked.  As i remember it amounted to about $1600 for the repair.  OUCH.  Frank or Fernando said the police bikes that came in there often had same thing going wrong with them.  It was not unusual at all for bikes with about 70-80k mi.

[Indy Dave]

While my photo might look ok, I can see a straight line at about 9 0-clock. It looks more like an intentional marking, but I guess I know better. This is on my 2010.

[greiffster]

3 hours ago, Indy Dave said:

While my photo might look ok, I can see a straight line at about 9 0-clock. It looks more like an intentional marking, but I guess I know better.

 

Dave,

Wiggle that mirror around a little.  If it is a crack you'll see it propagate through on the inner edge of the plastic like in my right side photo above.  It also helps to get some degreaser or cleaner and clean the surface of the plastic so the crack shows up better.

[dirtrider]

12 hours ago, Indy Dave said:

While my photo might look ok, I can see a straight line at about 9 0-clock. It looks more like an intentional marking, but I guess I know better. This is on my 2010.

 

Morning Dave

 

You need more light in that area (use a strong bright light), if the cam hub isn't clean then use some glass cleaner on a rag (or cotton glove finger) then clean the cam hub.

 

Looking in from the bottom rather than the top also seems to help show any cracks.

 

A smaller (clean) mirror will also help as you can work it around to get a better angle & view.

 

Depending on the original cam injection die some cams have almost no markings or lines & others seem to have a number of die cavity lines & intersections. (I have seen enough now to say that Bing must have a number of different injection dies as the surface lines & features vary quite a lot between different throttle bodies).

 

See photo below for crack vs normal cavity mold features_

 

 

 

 

[Indy Dave]

Good Morning D.R and Mike -

 

Thank you both. As mentioned, my mirror is the limiting factor in gaining a better view. That looks to be quite the nifty mirror you have, Mike. Where'd that puppy come from? DR, Thanks so much for the several diagrams and photos ["with circles and arrows"].

 

I believe what I'm seeing is a die cavity line, it's quite faint. I am able to see more of the cam hub myself than I can document while juggling the camera, light and bulky mirror.

[dirtrider]

Morning Dave

 

Just Google inspection mirror, or tilting head inspection mirror.

 

Lots of smaller ones to choose from.

 

Once you know what you want or need then visit your local auto parts store (or maybe even Wally World) as the local auto parts stores usually have a good selection of small   tilting head inspection mirrors.  

[greiffster]

11 minutes ago, Indy Dave said:

Good Morning D.R and Mike -

 

Thank you both. As mentioned, my mirror is the limiting factor in gaining a better view. That looks to be quite the nifty mirror you have, Mike. Where'd that puppy come from? DR, Thanks so much for the several diagrams and photos ["with circles and arrows"].

 

I believe what I'm seeing is a die cavity line, it's quite faint. I am able to see more of the cam hub myself than I can document while juggling the camera, light and bulky mirror.

 

I can't remember, maybe O'Reillys.  It's been sitting on my work bench in the package for a couple months as I had broken my other one. (you need lots of mirrors if you plan on working on a Mini Cooper.) It was a couple bucks and included a magnetic parts tray and flexible grabber thingy.  (you need several of those also for a Cooper).

[NoKick90]

Clearly this is no guarantee of immunity from the problem, but is there a known minimum mileage below which the cracks have not been detected? My '09 RT is at 19k, and it's just about to go onto the trailer for the haul out west for a couple of weeks. As a possible indication of a gentle former life [I guess], the valve clearances when checked last night were spot-on.

NoKick90

[dirtrider]

3 minutes ago, NoKick90 said:

Clearly this is no guarantee of immunity from the problem, but is there a known minimum mileage below which the cracks have not been detected? My '09 RT is at 19k, and it's just about to go onto the trailer for the haul out west for a couple of weeks. As a possible indication of a gentle former life [I guess], the valve clearances when checked last night were spot-on.

NoKick90 

 

Morning NoKick90

 

I don't think that you will find a mileage cutoff point, it seems to be a combination of factors with age, heat cycles,  (possibly mileage), ?????

 

I have heard of a 2008 that failed one cam & other was cracked at 27,000 so who knows.

 

The smart thing is to check the condition of your TB cams  before your trip (at least that could put your mind at ease or worst case change your plans).

 

A failed cam around your home area is an inconvenience but a failed cam on a trip would be trip ending & expensive.  

 

It only takes about 1/2 hour to remove the tupperware then doing the actual check is  not difficult with a light & mirror.

 

I guess the upside is there seems to be lot of 1200 TB cam cracks showing up on the 2005-2009 bikes  but you don't hear of a lot of  actual cam failures.

 

 

 

 

[KDeline]

Is there any running issues that warn you of the cracks? Bad idle, hesitation, rough, etc?

[longjohn]

27 minutes ago, KDeline said:

Is there any running issues that warn you of the cracks? Bad idle, hesitation, rough, etc?

For me it was hesitation on trying to accelerate.

[Ponch]

42 minutes ago, KDeline said:

Is there any running issues that warn you of the cracks? Bad idle, hesitation, rough, etc?

 

For me, there was no more throttle input. It just idled. This happened after accelerating after a light turned green.  January 7, 2015, a day that will live in plastic throttle body pulley infamy. 

[Qball 16]

I had my right side tupperware off (shift linkage service) so I had a look at that side.  I don't have a real inspection mirror, so I cobbled together a makeshift tool after 'borrowing' a small makeup mirror of my wife's.  Couldn't get a great view, but good enough to see what appears to be a small crack 

 

I'm in the club, yay...  Mine's an 06 RT with <60,000km

 

I'll probably bite the bullet sometime this summer, and get the Beemer Bits aluminum replacement cams - gulp, they'll be $600+ CAD after exchange & shipping.  Doing the Bing cams with or without the shaft - and the potential base idle screw setting problems - sounds a weeeeeee bit outside my mechanical comfort level 

[Rogerl]

I have a 2013 R1200R with 30,000 miles. I only had to remove two small covers, (4 screws total) and the breather hose on the left cylinder and I was able to lift the covers and look at the cam hubs from underneath. I used some simple green cleaner on a paper towel to clean the face of the cam hub. There were two lines that went across the face of the hub. Upon real close inspection they were both casting marks on the face of the hub. Both of the hubs have the same marking. I looked long and hard to determine if casting lines were cracks but the lines were not cracks. 

I will do this every spring to make sure that the hubs are not cracking. It might be a time thing that the older bikes are showing the problem because they have been out there exposed to the heat of the engine for a longer time.  

 

Thanks

Roger L 

[dirtrider]

____ new shafts/cams  arrived____

 

The  (L/H side) shaft/cam is now installed_

 

Here is a quick look at the new TB cam/shaft, -- plastic material seems the same shape & same thickness, & plastic looks to be the same  <POM>  ( Polyoxymethylane ).

 

They have now added a screw/washer  (don't know why), might be a safety thing, or possibly the cam is now held on with screw & not a tight press (this would be nice as the cam could be replaced in the future  without much effort). Secondary throttle return spring now j-u-s-t touches that screw head at wide open throttle (not ideal but not enough interference to effect anything) 

 

I am doing the L/H (hardest due to TPS ) side first as a verification test of my 'simple' install process .

 

In any case,  I used (tested)  my NEW (simple procedure ) no GS-911 required & possibly no base idle screw adjustment. Even if using a GS-911 this procedure is probably the best way as hopefully the throttle bodies will go back on the engine fairly close to matched then just use GS-911 to verify. 

 

New shaft/cam went in easy  (well sort of anyhow)  & throttle plate re-lined up to my 'before disassembly' scribe marks (with some finagling and a few alignment retries) .

 

With all re-assembled & checked for accuracy (3 checks ) it seems back to very close to it was before. With my 'pre-disassembly' throttle valve shims installed, comparing to the before measurements, the base idle screw to throttle shaft stop arm is close to where it was  but not exact (was .0015"  before disassembly & is now a tight .003" (closer than I thought it might end up with a complete new shaft & new cam) . I'm still debating on (IF) I want to adjust the base idle screw to get the gap down to the original.0015" or just leave it at a tight .003" & see how it works out.

 

I did work with the throttle valve placement & screw loosening/wiggling/tightening a number of times until I got it to the lowest idle screw to stop arm gap (started out over .006" but by fiddling with it a few times I managed to quickly work it down to that tight .003".

 

I am sort of  thinking (debating)  that the .0015" vs the .003" might force me to now do the other side before installing both TB's  on the engine for testing.

If the R/H side ends up at the same .003" (or close) after reassembly then I am just going to leave them both at the .003" & run with it. If the R/H  side  comes in at closer to it's original .0015" then I will probably match the L/H side to the .0015".

 

If (when) I get the (DR/simple) shaft/cam install procedure worked out & proven I will post the procedure here  (from a sample of 1 today I t-h-i-n-k it is going to work out). It should be much better (more accurate) than the Bing USA  in-house procedure as their procedure seems to be questionably  accurate (no flow bench or inclinometer used) just a guess based on base idle screw position still being correct. But probably not as good as Bing Germany's OEM procedure but  Bing Germany  won't release their procedure (probably air flow related but their lips are sealed).