Throttle Body Pulley Repair

[aggieengineer]

After reading about the failures some other riders had experienced, I decided to have a look while the plastic was off for some routine maintenance. I really didn't expect to find anything wrong. 

Wrong!

 

This is the left side:

 

 

This is the right side. Note that there are actually three cracks in this one - 9:00, 3:00, and at the 7:30 position. 

 

I think this is a matter of age and heat causing the plastic to shrink and become brittle. I don't ever twist the throttle to the stop while riding, and don't believe this is self-induced. The third smaller crack is evidence of that. Throttle cable tension does not put significant stress on  that location.

The bike is 11 years old, but with only 42,000 careful miles. 

 

Here are the options:

 

1. Send it to the Bing Agency for repair with the same part. I called their Technical Service number, and had a very informative chat. Replacement of both pulleys is $312, but long-term I can expect the problem to recur. 

2. Replace the pulleys with metal ones from Beemer Bits for a somewhat shocking $450....plus shipping! 

 

I'm inclined at this point to go with the metal parts and just be done with it. Has anyone installed them yet? I'd love to hear what the process was like. 

 

[dirtrider]

2 hours ago, aggieengineer said:

Here are the options:

 

1. Send it to the Bing Agency for repair with the same part. I called their Technical Service number, and had a very informative chat. Replacement of both pulleys is $312, but long-term I can expect the problem to recur. 

2. Replace the pulleys with metal ones from Beemer Bits for a somewhat shocking $450....plus shipping! 

 

I'm inclined at this point to go with the metal parts and just be done with it. Has anyone installed them yet? I'd love to hear what the process was like. 

 

 

 

Evening Aggieengineer

 

Personally I haven't done the alloy ones but I do know a rider in my area that did his own with no issues & he isn't all that mechanically inclined.

 

Beemer Bit has (had anyhow)  detailed install instruction on their web site. I haven't looked lately but  last that I looked it looked pretty simple. (the good part is that the difficult to re-set-correctly idle stops are on the remaining arm so that should make it easier as setting the base air-flow (base idle stop screws) is the difficult part to get set back to correct.

 

I have installed a couple of sets of the Bing OEM shafts/cams & those are not hard to install but a bit fiddly to get the  base idle screws back close to correct.

 

The Bing shafts/cams (parts only) are a LOT cheaper than having them do it, or buying  the Beemer Bits parts, or having them do the repair.

 

With the Bing parts-only method  you need to do some preliminary balance checks & record those then do 'ONLY' one side at a time using the existing factory Throttle Body as a known.

 

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

[lkraus]

Bing sells the parts if you want to DIY.  Pulleys on shafts for ~$100/ pair. Should be good for another 8-10 years. Or Pulleys only for ~$40, but reportedly tricky to mount on the shafts.  Or go full shade-tree mechanic and reinforce what you have with a big washer and JB Weld.

 

Looks like I need to find a touch-typing class....

[Ponch]

Mine broke after 5 years. I just found a set of throttle bodies on ebay. There wasn't a repair then from bing or Beemer bits. The only other option was new throttle bodies. I made a complaint to the NHTSA or whatever government agency it was. There were others for the same thing. BMW kind of conformed to Eilenberger's Axiom (Which was related to the fuel strip):

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

 

It soured me on BMW for awhile. I've since learned their cars use a lot of crappy plastic on engine pieces that crumble with time. I just find it lunacy that they would build it like that. 

[Shane J.]

19 hours ago, lkraus said:

Bing sells the parts if you want to DIY.  Pulleys on shafts for ~$100/ pair. Should be good for another 8-10 years. Or Pulleys only for ~$40, but reportedly tricky to mount on the shafts.  Or go full shade-tree mechanic and reinforce what you have with a big washer and JB Weld.

 

Looks like I need to find a touch-typing class....

So the big washer is the reinforcement and the JB Weld to hold it to the plastic cam? Sounds like a good preventative measure even if they are not cracked yet. Reasonable assumption?

[dirtrider]

20 minutes ago, Shane J. said:

So the big washer is the reinforcement and the JB Weld to hold it to the plastic cam? Sounds like a good preventative measure even if they are not cracked yet. Reasonable assumption?

 

 

Afternoon   Shane J.

 

I'm not sure about that one as without peripheral support I doubt that a washer & JB would prevent that plastic hub from  cracking  but it would cover any cracking up so you couldn't see it with an inspection.   

[Ponch]

8 hours ago, dirtrider said:

 

 

Afternoon   Shane J.

 

I'm not sure about that one as without peripheral support I doubt that a washer & JB would prevent that plastic hub from  cracking  but it would cover any cracking up so you couldn't see it with an inspection.   

I was going to mail my old ones back to BMW with a big FU on a note inside, but then I thought better of it as they'd probably have me arrested for terrorism.  It's beyond JB Weld though. It's bad engineering and poor execution. The right repair is the metal one, at least with what we know now. 

[aggieengineer]

I agree. A set of aluminum replacements is on the way. I'll post some additional information on the install. Surely I'm not the last person who will have to deal with this. 

Fate being what it is, however, I suspect a recall will be issued about fifteen minutes after I finish the project. 

[Ponch]

1 hour ago, aggieengineer said:

I agree. A set of aluminum replacements is on the way. I'll post some additional information on the install. Surely I'm not the last person who will have to deal with this. 

Fate being what it is, however, I suspect a recall will be issued about fifteen minutes after I finish the project. 

 

And if there's a recall, what recourse do I have? Unless I had a dealer fix it, none I imagine. Seems more and more people are having this happen too. I was an early adopter. 

[dirtrider]

18 minutes ago, Ponch said:

 

And if there's a recall, what recourse do I have? Unless I had a dealer fix it, none I imagine. Seems more and more people are having this happen too. I was an early adopter. 

 

Morning Ponch

 

You do (might)  have some recourse (if like the fuel pump pass through recall) as BMW had a special policy to reimburse riders for some of the cost encountered from non-BMW repair if receipts were shown (obviously it didn't reimburse for the entire amount).  

[Ponch]

3 minutes ago, dirtrider said:

 

Morning Ponch

 

You do (might)  have some recourse (if like the fuel pump pass through recall) as BMW had a special policy to reimburse riders for some of the cost encountered from non-BMW repair if receipts were shown (obviously it didn't reimburse for the entire amount).  

I guess that remains to be seen. I have my doubts they'd ever address it, but riders that have this problem need to put in a complaint to the feds. 

[aggieengineer]

Well, it's done, to a point. The original plastic pulleys came off easily. The plastic was fairly brittle. I used a pair of small sidecutters for the job.

 

 

 

I did encounter one problem. On the right unit, there was not adequate clearance between the throttle arm and the throttle body casting. The new aluminum pulley was binding. It is only two-thousandths thicker in that area than the plastic part. 

The technician from Beemer Bits said that they sometimes have to file away a bit of the body casting for clearance. There was about ten-thousandths axial play in the shaft, so I took a chance and loosened the butterfly screws and slid the shaft out a bit. Collective cringe...I know. I was as careful as I could be to maintain the gap between the butterfly and the throat accurately, and identical under bright light to the left (unmolested) unit. There seems to be a bit of manufacturing slop in this throttle. 

 

After that, it went together smoothly. Fit was very nice. The left side went on without any problem. 

 

Now for the scary part. I reinstalled the units, hooked up the GS-911 and vacuum balancer for a test. 

Idle was the same as before, and throttle balance was unchanged. I expected some problem, but so far nothing.

 

I'm going to try to attach some data logs for anyone interested. Here goes.

Log b.pdf

 

[dirtrider]

3 hours ago, aggieengineer said:

Well, it's done, to a point. The original plastic pulleys came off easily. The plastic was fairly brittle. I used a pair of small sidecutters for the job.

 

 

 

 

I did encounter one problem. On the right unit, there was not adequate clearance between the throttle arm and the throttle body casting. The new aluminum pulley was binding. It is only two-thousandths thicker in that area than the plastic part. 

The technician from Beemer Bits said that they sometimes have to file away a bit of the body casting for clearance. There was about ten-thousandths axial play in the shaft, so I took a chance and loosened the butterfly screws and slid the shaft out a bit. Collective cringe...I know. I was as careful as I could be to maintain the gap between the butterfly and the throat accurately, and identical under bright light to the left (unmolested) unit. There seems to be a bit of manufacturing slop in this throttle. 

 

 

After that, it went together smoothly. Fit was very nice. The left side went on without any problem. 

 

 

Now for the scary part. I reinstalled the units, hooked up the GS-911 and vacuum balancer for a test. 

Idle was the same as before, and throttle balance was unchanged. I expected some problem, but so far nothing.

 

I'm going to try to attach some data logs for anyone interested. Here goes.

 

 

 

Afternoon aggieengineer

 

The numbers that you posted look good but they might change after the adaptives re-lean as you ride it & it goes through a couple of  ignition cycles.

 

If your hot engine TB balance stays within reason  with locked steppers after a few rides & the hot  engine idle  stepper count stays close with unlocked steppers then you are golden.    

[aggieengineer]

Hopefully I dodged a bullet on this one. I stuck a seat on it and took it for a short ride to see if I could induce any misbehavior, for example rapid drop to idle from cruise. Seems fine so far. 

I'm busy helping my son with car shopping this afternoon, then have a 3-day airline trip, so the full test will happen next week. 

I have to say that it is very reassuring to have some expert help to smooth the way. Thanks indeed!

[aggieengineer]

Before I forget about this, there was one piece of the original pulleys that required some effort to extract since it was molded onto the throttle arm.

 

 

I carefully ran a drill bit (#21 I think) through the hole to remove the plastic in the hole in the throttle arm, and that released the flat piece which had remained on the backside.

 

Also, I didn't use the blue Loctite 242 which was supplied, instead substituting Permatex 64000 sleeve retainer. Not likely to make a difference, but I'm hopelessly conservative. 

 

Standing by for the recall......

 

 

[Ponch]

24 minutes ago, aggieengineer said:

Before I forget about this, there was one piece of the original pulleys that required some effort to extract since it was molded onto the throttle arm.

 

 

I carefully ran a drill bit (#21 I think) through the hole to remove the plastic in the hole in the throttle arm, and that released the flat piece which had remained on the backside.

 

Also, I didn't use the blue Loctite 242 which was supplied, instead substituting Permatex 64000 sleeve retainer. Not likely to make a difference, but I'm hopelessly conservative. 

 

Standing by for the recall......

 

 

 

Put in a complaint with the feds. I did. The more people do, the more likely there will be a recall. 

 

[Mark C]

Have cracked another one and think it is a real recall type problem, All this could be avoided with metal pulleys like old days. 

 New improved is actually backwards bullshito. 

 Drilled and safety wired with expoxy and flat washer to re-use.

Wondering how to LIMIT cable pull from going to end of throttle stop? I myself don't ever really use 100 % throttle pull and would give up a slight amount to never have this problem again, especially on the road when you snap it while passing cars on a back road!

[dirtrider]

37 minutes ago, Mark C said:

Have cracked another one and think it is a real recall type problem, All this could be avoided with metal pulleys like old days. 

 New improved is actually backwards bullshito. 

 Drilled and safety wired with expoxy and flat washer to re-use.

Wondering how to LIMIT cable pull from going to end of throttle stop? I myself don't ever really use 100 % throttle pull and would give up a slight amount to never have this problem again, especially on the road when you snap it while passing cars on a back road!

 

Morning Mark

 

The problem is BMW is just about out of the woods so to speak on any Hexhead recall liability. There are exceptions & outliers but for the most part  "there is a limit on how far back a manufacturer has to go to fix problems without charging the owner. Vehicles eligible for no-cost repair can't be more than 10 years old as of the date the defect was determined".

 

I'm not sure what date is used as far as 'date the defect was determined' but that would probably be when a NATSA safety investigation was officially started, or maybe not until it is  officially  concluded.

 

If this problem would have been reported on a soccer mom's mini van, or a senators nephew's motorcycle then it would probably have been addressed already. But seeing as it is happening on a 'perceived'  dangerous motorcycle then it doesn't put up much of a red flag until a number of fatalities or injuries can be tracked directly back to the problem. 

 

Plus, unless ALL the failures are reported to NATSA under the exact same heading & subheading with about the same failure wording then NATSA doesn't seem to be able to  put 2+2 together & start an investigation.

 

Get it on the national news with a death or couple of injuries THEN it will get addressed.

[Ponch]

35 minutes ago, dirtrider said:

 

Morning Mark

 

The problem is BMW is just about out of the woods so to speak on any Hexhead recall liability. There are exceptions & outliers but for the most part  "there is a limit on how far back a manufacturer has to go to fix problems without charging the owner. Vehicles eligible for no-cost repair can't be more than 10 years old as of the date the defect was determined".

 

I'm not sure what date is used as far as 'date the defect was determined' but that would probably be when a NATSA safety investigation was officially started, or maybe not until it is  officially  concluded.

 

If this problem would have been reported on a soccer mom's mini van, or a senators nephew's motorcycle then it would probably have been addressed already. But seeing as it is happening on a 'perceived'  dangerous motorcycle then it doesn't put up much of a red flag until a number of fatalities or injuries can be tracked directly back to the problem. 

 

Plus, unless ALL the failures are reported to NATSA under the exact same heading & subheading with about the same failure wording then NATSA doesn't seem to be able to  put 2+2 together & start an investigation.

 

Get it on the national news with a death or couple of injuries THEN it will get addressed.

 

the more people put in complaints, the more likely they'll do something. I have a feeling people just fix it and move on, not holding BMW responsible for shoddy engineering and manufacture. If the NHTSA can't figure it out, what prompted the fuel strip recall? I think this is more serious. I know on the car side, BMW has lousy plastics on engine parts that fail where metal parts wouldn't have. Got to wonder what crack they're smoking. 

[dirtrider]

16 minutes ago, Ponch said:

 

the more people put in complaints, the more likely they'll do something. I have a feeling people just fix it and move on, not holding BMW responsible for shoddy engineering and manufacture. If the NHTSA can't figure it out, what prompted the fuel strip recall? I think this is more serious. I know on the car side, BMW has lousy plastics on engine parts that fail where metal parts wouldn't have. Got to wonder what crack they're smoking. 

 

Morning Ponch

 

I don't believe there was a fuel strip recall, it was more of an offered extended warranty on failed strips not a real (return all vehicles) type recall.

 

My guess is that BMW did the extended warranty in  an effort to prevent further investigation & prevent a forced recall.  

 

The problem for BMW with a forced recall would have been that they would have needed to come up with a real (verified) lasting fix. THAT would have been W-A-Y more expensive than just replacing fuel strips on the ones that failed.

[Ponch]

29 minutes ago, dirtrider said:

 

Morning Ponch

 

I don't believe there was a fuel strip recall, it was more of an offered extended warranty on failed strips not a real (return all vehicles) type recall.

 

My guess is that BMW did the extended warranty in  an effort to prevent further investigation & prevent a forced recall.  

 

The problem for BMW with a forced recall would have been that they would have needed to come up with a real (verified) lasting fix. THAT would have been W-A-Y more expensive than just replacing fuel strips on the ones that failed.

 

Well, ultimately, it's on them and I'll give them credit for waking me into reality about their products. To me, considering the cost/niche of their machines, this kind of stuff is totally unnecessary and ridiculous. 

[large-stache]

Nice writeup and pics.  I just did mine yesterday.  I ordered the aluminum cams as a preemptive measure for an upcoming trip.  When I removed the throttle bodies, both were cracked, and the right one broke off when I slightly pushed on it with my thumb.  I hate to think it could've failed on my next ride.  Expensive yes, but the peace of mind is worth it.

[Ponch]

19 minutes ago, large-stache said:

Nice writeup and pics.  I just did mine yesterday.  I ordered the aluminum cams as a preemptive measure for an upcoming trip.  When I removed the throttle bodies, both were cracked, and the right one broke off when I slightly pushed on it with my thumb.  I hate to think it could've failed on my next ride.  Expensive yes, but the peace of mind is worth it.

File it with the gov. 

[jim.t]

Hello everyone. I have just recently discovered this site and immediately clicked on hexheads since I ride a 2007 R1200R with 66K miles. Didn't take long to notice all the chatter about the TB cam problem. Fast forward to today with nice weather I rolled the bike out, pulled off a few pieces of plastic, got out my trusty inspection mirror and found a hairline crack in my left TB. I haven't noticed any recent ( since 2019 ) complains. I'm sure the problem has not gone away and I'm the original owner so I would have gotten notice if the was a recall ( LOL ). My question is is there a different fix other than what I have read so far. Thanks in advance. Jim.

[9Mary7]

I am using epoxy with a thin washer reinforcement on my '05s cracks to see how durable that cheapskate method is. My '11 is not showing any cracks as of today, so I await a failure on the '05 for now.......  

[dirtrider]

On 3/30/2021 at 7:35 PM, jim.t said:

Hello everyone. I have just recently discovered this site and immediately clicked on hexheads since I ride a 2007 R1200R with 66K miles. Didn't take long to notice all the chatter about the TB cam problem. Fast forward to today with nice weather I rolled the bike out, pulled off a few pieces of plastic, got out my trusty inspection mirror and found a hairline crack in my left TB. I haven't noticed any recent ( since 2019 ) complains. I'm sure the problem has not gone away and I'm the original owner so I would have gotten notice if the was a recall ( LOL ). My question is is there a different fix other than what I have read so far. Thanks in advance. Jim.

Morning Jim 

 

You tacked your problem on to someone else's thread so we didn't notice it. In the future please start your own NEW thread on YOUR own problem.

 

On throttle body options: 

 

There are some other options, you can find some decent used throttle bodies on E-Bay, or online, but the chance of these developing the same cracking problem is high.

 

You can spend BIG MONEY to buy new throttle bodies from BMW (that is usually how the dealer repairs the problem). 

 

You can order new cams from Bing USA  & install those per the direction in the other threads. Not terribly difficult but the person doing the job needs to be mechanically competent & needs to able to work with good precision.   

 

You can order new cams already pressed on new throttle shafts  from Bing USA  (this is my recommendation if doing the job yourself), then install those per the direction in the other threads on this site. Not terribly difficult but the person doing the job needs to be mechanically competent & needs to able to work with good precision. 

 

You can remove your throttle bodies then send them to Bing USA to install new cams, or install new cams on new shafts. This is the easy way out that doesn't cost a great amount of money "BUT"  Bing USA ONLY installs the shafts, or shafts & cams, without doing any pre-measuring or post-install setup. They basically just toss in the new parts then return your throttle bodies, no setup, no precision adjustments, no test to verify that the air flow is anywhere near where it was from the factory.    If you are lucky then they work OK, if not then the thing will never run quite as good as it did from the factory. 

 

There are also some more expensive aluminum  cams that install on your existing throttle levers (after you remove the plastic cam parts). These do not change the basic air flow at idle so no need to do the pre & post measurements. There is some expertise needed in installing these but otherwise pretty straight forward.   

 

   

[jim.t]

Thanks dirtrider for responding to my misdirected question. I am of a certain age and not very adept at navigating these sites. I will try to do better. I certainly enjoy reading your responses to questions.

[Ponch]

I'd like to read @dirtrider 's commentary on this. 

[chrisolson]

38 minutes ago, Ponch said:

I'd like to read @dirtrider 's commentary on this. 

That post you referenced is under review as  duplicated in several forums and as possible advertisement

[Ponch]

5 minutes ago, chrisolson said:

That post you referenced is under review as  duplicated in several forums and as possible advertisement

OK. I was reserving comment. One, I have no idea where I would get it, BUT, it's as much work as getting the bing part and whoever did it, didn't seem to check throttle blade alignment. If I have to drill, I might as well get the parts from the guy in Tucson. It would be easier/less fuss. 

[lkraus]

 

1 hour ago, Ponch said:

OK. I was reserving comment. One, I have no idea where I would get it, BUT, it's as much work as getting the bing part and whoever did it, didn't seem to check throttle blade alignment. If I have to drill, I might as well get the parts from the guy in Tucson. It would be easier/less fuss. 

They looked like a variation on the metal pulleys that I used from beemerbits.com, at a fraction of the cost.  No changes are made to the throttle blade alignment, and my cable sync was still acceptable (1 in-H2O) when I put it back together.  They were expensive, but they will never crack again.

[Shane J.]

Even if it is an ad I would be interested in being able to research it.

[KetoSoi]

I have seen a pulley kit out of Europe. A guy has a site where he used that kit, but it requires you to remove the shaft to install, he modified it so the shaft doesnt have to be removed. I'll see if I can find his how-to again, but I dont want to run afoul of the site policies here either.

 

K

[KetoSoi]

I cant find that guys site now. Did find the product though, an outfit out of Bulgaria. Gets solid reviews of the places I've read through, and quite a bit cheaper that the beemerbits version of the fix.

K

 

[IVAN_Ivanov]

I will leave a YouTube link to see this solution for repairing pulleys.

 

[lkraus]

After viewing the video, I see that these pulleys are NOT like the Beemer-Bits solution.  The Beemer-Bits pulleys do not require removing the throttle plates or shafts, so there is no fussing with plate clearances. 

[KetoSoi]

59 minutes ago, lkraus said:

After viewing the video, I see that these pulleys are NOT like the Beemer-Bits solution.  The Beemer-Bits pulleys do not require removing the throttle plates or shafts, so there is no fussing with plate clearances. 

 

This is what I vaguely referred to in my previous reply. There was a guy who did a how-to on these, and modified the retaining ring (looked like a horse shoe), so it would slide onto the shaft from the side, i.e. no reason to remove the shaft, etc. I cannot find that site now, I should of bookmarked it, ugh.

 

K

 

[pwillikers]

I inspected the throttle body cams on my '11 R12RT and, no surprise, they're both cracked and have been "repaired" with a blob of epoxy by the prior owner.

 

I'm going to pursue repairing them properly.   What is properly you might rightly ask?  I'm thinking the ebay ones displayed in the youtube posted above are the best option.  However, the youtubes have little detail.

 

I'm looking for guidance on the necessity and procedure for calibrating them after installation.   Please advise (DR).  Thanks.

[dirtrider]

12 hours ago, pwillikers said:

I inspected the throttle body cams on my '11 R12RT and, no surprise, they're both cracked and have been "repaired" with a blob of epoxy by the prior owner.

 

I'm going to pursue repairing them properly.   What is properly you might rightly ask?  I'm thinking the ebay ones displayed in the youtube posted above are the best option.  However, the youtubes have little detail.

 

I'm looking for guidance on the necessity and procedure for calibrating them after installation.   Please advise (DR).  Thanks.

Morning pwillikers

 

I am not familiar the replacement cams you intend to install. 

 

Are you going to try to install them without disassembling the throttle bodies  (removing the throttle plates & shafts)? If so then you won't need to calibrate anything except the above idle throttle balance & verify that both sides track correctly throughout the throttle opening range. You will want to check the (held stepper) hot idle cross side balance though just as a verification. 

 

As I mentioned, I know nothing about those cams you are looking at so I have no experience with their cable tracking accuracy (are both side cams cut with the exact same cable track profiles? Also, do they mount to the TB throttle levers with the exact clocking on both sides?  The cam cable slots can be machined correctly but if the mounting holes or the mounting screws are not exact and/or a tight fit then the cam phasing will be off so each side throttle plate can track differently.       This is important to consider. 

 

Also, will those cams that you are looking at clear the return springs (the return springs run  pretty darn close to the thinner factory POM cams). 

 

If you intend to take the throttle bodies apart (remove throttle plates & remove the throttle shafts) then my suggestion is to get a GS-911 on that motorcycle prior to disassembling anything so you can verify that it is somewhat correct BEFORE disassembly. That also gives you a baseline to use for checking (validating) your after install work. 

 

Are those cams that you are looking at hard anodized?  If not then you might have some long-term cable track wear, not a big deal unless you get dissimilar track wear due to one side wearing more than the other side. 

 

In any case, if you plan on removing the throttle plates & throttle  shafts then the link below might be of some help. That is how I install factory replacement BING shafts & cams. Or the procedure can be used if the factory shafts are re-used with new BING cams installed on those shafts. 

 

I typically install the BING shaft/cam assemblies as it isn't worth the extra work to grind the OEM shaft peening off then drill/tap the shaft ends to take retaining screws. It is also easy to bend the shafts when pressing (or driving) the new cams onto the old shafts (sometimes they can just be pulled on using the retaining screws). I haven't bought any new BING USA cam/shaft assemblies for a while now as I bought a few extras a while back, someone posted a while back that only the cams were available, I don't know if that is still the case?  

 

https://www.bmwsporttouring.com/topic/92006-posted-to-see-how-a-tb-shaft-install-how-to-reads-in-a-full-thread/

 

Bing throttle cams & cam/shaft parts_____     https://bingcarburetor.com/throttlebodies.html#/

 

[pwillikers]

Thank you for the reply DR.

 

It appears necessary to remove the throttle plates and shafts to install these replacement cams.  I can't envision how to install them otherwise.

 

The youtube video linked above shows how they replace broken plastic cams with their aluminum replacements.  They show nothing with respect to recalibrating.  The replacement cams are apparently very accurately positioned on the metal backing plates that are integrated with the throttle plate shafts.  There appears to be little to no wiggle room.  Does this accuracy obviate the need for recalibration after installation?

 

Thanks for the link to your excellent procedure for "recalibrating".  I will follow it to the letter.

 

Here's their description.  Hard anodization is included.  

Quote

Repair kit contents:

The repair kit includes pair of cams (left and right) made of aluminum alloy 6082 T6. Also the elements passes through electrochemical anodization process to improve the surface durability of the aluminium alloy , after which color is added for aesthetics.

The kit also contains fastening element M3 screws and a small flanges with threaded holes M3, all made from stainless steel.

 

For information, here's yet another ebay aluminum replacement throttle body cam.  This one has pictures in the ebay listing of your feeler gauge technique but with no explanation - so quite lacking by comparison.

[dirtrider]

20 minutes ago, pwillikers said:

Thank you for the reply DR.

 

It appears necessary to remove the throttle plates and shafts to install these replacement cams.  I can't envision how to install them otherwise.

 

The youtube video linked above shows how they replace broken plastic cams with their aluminum replacements.  They show nothing with respect to recalibrating.  The replacement cams are apparently very accurately positioned on the metal backing plates that are integrated with the throttle plate shafts.  There appears to be little to no wiggle room.  Does this accuracy obviate the need for recalibration after installation?

 

Thanks for the link to your excellent procedure for "recalibrating".  I will follow it to the letter.

 

Here's their description.  Hard anodization is included.  

 

For information, here's yet another ebay aluminum replacement throttle body cam.  This one has pictures in the ebay listing of your feeler gauge technique but with no explanation - so quite lacking by comparison.

Evening pwillikers

 

I don't have a connection to view videos at the moment (lucky to even have a rather poor connection).

 

Here is the deal,  (IF) you remove the throttle plates & shafts then you will have to properly re-center & perfectly re-clock the throttle plates & most likely check/reset the base idle screws.

 

If you don't want to do all of that then the "Beemer Bits" alloy cams are probably a much better choice, if precisely installed those only need a basic above idle cross side balance check/adjustment as they can be installed without removing the throttle shafts or messing with the idle settings. 

 

Here is kind of the bottom line____  IF you need to remove throttle plates, or remove the throttle shafts, or mess with the metal shaft levers (those contain the idle stops ) then you will have to go through the entire check/reset/idle balance thing. 

 

  

[SHIMHEAD]

Hi all,

     I ordered a set of the cams from Bulgaria via eBay, showing delivery by June 29th. Once in hand I'll post some detailed pics of them. If it appears that the retaining rings will have sufficient strength, I may consider sectioning them to allow installation of the cams without shaft removal. It may also be possible to drill different mounting holes that would include tapping the existing cam plate attached to the throttle shaft. Then screws could attach the new cam directly to the shaft plate. I don't plan to proceed with installation until I'm satisfied with the potential final outcome. Will be looking for feedback as well before I commence with installation.

[KetoSoi]

14 hours ago, SHIMHEAD said:

Hi all,

     I ordered a set of the cams from Bulgaria via eBay, showing delivery by June 29th. Once in hand I'll post some detailed pics of them. If it appears that the retaining rings will have sufficient strength, I may consider sectioning them to allow installation of the cams without shaft removal. It may also be possible to drill different mounting holes that would include tapping the existing cam plate attached to the throttle shaft. Then screws could attach the new cam directly to the shaft plate. I don't plan to proceed with installation until I'm satisfied with the potential final outcome. Will be looking for feedback as well before I commence with installation.

 

Been looking at this one myself. I wish I could find the website I had mentioned earlier. The horseshoe modification did work for that guy. The retaining ring was indicated as stainless, and should be strong enough given that there is no lateral movement of the pulley. Since it is also keyed to the end of the shaft, and the cable/pulley action is longitudinal, it should function reliably. Very curious to see what you come up with.

 

The BeemerBits ones are very nice as well, and the design also seems solid, theyre just outrageously expensive IMHO.

 

K

 

[SHIMHEAD]

Hi all,

      Throttle cams came in from Bulgaria today, pretty quick shipping I think. They look to be nicely machined, but the colored coating is a bit inconsistent, possibly parts from different batches when coating/coloring. I took some pics which are attached. Screws are 3 x 6 mm, threads seem well cut in the holes in the back-up ring. Some of the pics include measurements. It may be 3-4 weeks before I get an opportunity to install these, but I am leaning towards shaft removal for the best possible durability. I have not had any of these cracked cams in my hands to this point, so I don't know the measurements of the shaft cam plate to which these will mount, nor the fit tolerance of the new cams to that plate, but I am hopeful that it will be suitable for a lasting repair. 

     Please ask any questions, or provide your comments so I can make sure I have an abundance of input prior to my endeavors.....

I can take more pics if anyone wants them.

[SHIMHEAD]

A few more pics....

[dirtrider]

17 hours ago, SHIMHEAD said:

Hi all,

      Throttle cams came in from Bulgaria today, pretty quick shipping I think. They look to be nicely machined, but the colored coating is a bit inconsistent, possibly parts from different batches when coating/coloring. I took some pics which are attached. Screws are 3 x 6 mm, threads seem well cut in the holes in the back-up ring. Some of the pics include measurements. It may be 3-4 weeks before I get an opportunity to install these, but I am leaning towards shaft removal for the best possible durability. I have not had any of these cracked cams in my hands to this point, so I don't know the measurements of the shaft cam plate to which these will mount, nor the fit tolerance of the new cams to that plate, but I am hopeful that it will be suitable for a lasting repair. 

     Please ask any questions, or provide your comments so I can make sure I have an abundance of input prior to my endeavors.....

I can take more pics if anyone wants them.

Morning SHIMHEAD

 

A couple of thoughts___ It is difficult to tell from the pictures but that yellow coating looks to me more like powder-coating than anodizing.

 

If those cams are actually powder-coated with a somewhat thick powder-coating instead of being anodized that could eventually lead to the retention screws losing some of their clamp load as the cams go through heat cycles. 

 

I'm also not sure how precisely the OEM shaft levers are stamped as there is no reason to precisely hold the lever cutout notches to a tight tolerance as the  the plastic cams are just molded to what they are (those lever notches probably aren't used for anything precision)

 

So when installing the new cams do not mess with any of the cable adjustments during TB removal or TB re-installation.  

 

Then when the TB's are reinstalled check the cross side TB balance as you open & close the throttles using the twist grip. If both sides track the same as before TB removal, or just track the same side to side, then the cams are located on the levers correctly & the the cams are both machined to the same profile. 

 

If those cams are in fact powder-coated then you might re-check the cross-side (above idle) balance after a few thousand miles of use to see if the cables are wearing the powder-coating in the cable grooves therefore effecting the cross-side balance.

 

 

[SHIMHEAD]

Dirtrider,

      As always, thank you for your insight/input. You are without a doubt an endless source of detailed information that is helpful to anyone taking the time to listen. I'm not sure how you manage to keep doing it. 

     I do believe the coating is anodizing. Is there any measurement you would suggest I take on the throttle body cam prior to removing the original plastic? Possibly to compare to the measurement after the new cams are installed?  

[dirtrider]

1 hour ago, SHIMHEAD said:

Dirtrider,

      As always, thank you for your insight/input. You are without a doubt an endless source of detailed information that is helpful to anyone taking the time to listen. I'm not sure how you manage to keep doing it. 

     I do believe the coating is anodizing. Is there any measurement you would suggest I take on the throttle body cam prior to removing the original plastic? Possibly to compare to the measurement after the new cams are installed?  

Afternoon SHIMHEAD

 

You might be able to set the TB's up on a granite block then use a degree wheel & a long-stinger dial indicator to measure & plot the cable tracks per every 5° or 10° of cam rotation but that is a lot of work for what you get. 

 

Your best bet (probably the way I would do it) is to lock the idle steppers, then  see what your hot engine pre-install above idle cross-side balance is. (probably 2k, 3k, 4k, & 5k) then do the same after the new cam install. I wouldn't worry about anything much over 5k as by then the throttles are so far open a little cross-side difference is not a big deal (much lower engine vacuum at road load).

 

If you don't have a GS-911 to lock the steppers you can work around that. Just start then warm the engine up, then shut it off for a very short time, then re-start it & do your cross side check right then (the steppes usually stay locked in step for a while  right after a warm engine start) 

[KetoSoi]

On 6/17/2023 at 12:04 PM, SHIMHEAD said:

Hi all,

      Throttle cams came in from Bulgaria today...

Those look pretty good. When you install, I would put some light grease in the cable track on those, it'll help prevent any cable grind on the anodize over time.

 

If anyone knows the diameter of the shaft, those rings certainly do look like a candidate for a horseshoe modification.

 

K

 

[bruce2000ltc]

23 hours ago, KetoSoi said:

Those look pretty good. When you install, I would put some light grease in the cable track on those, it'll help prevent any cable grind on the anodize over time.

 

If anyone knows the diameter of the shaft, those rings certainly do look like a candidate for a horseshoe modification.

 

K

 

I agree about those rings.  I'm thinking about getting a set from Bulgaria and cutting a horseshoe slot to clear the shaft with a thin cutoff wheel on my Dremel.  Even if I had to cut the ring in two pieces I think it would still work fine or am I missing something here?