Is my final drive toast? Or about to be?

[syntorz]

Looking for same help over at k-bikes.com.

 

2011 K1300S 25k miles

Noticed some play in the rear wheel at last final drive oil change. Drain oil came out clear, no particles or metallic sludge like other's pics I've seen, but then again I didn't look real close. Probably put on another 1500 miles since then.

So after reading many many stories about GS and RT final drive problems, decided I'd better look into this more. First thing I did was dismounted the brake caliper and spun the rear wheel. Didn't pick up any unusual noises or sensations. I made up a quick-n-dirty base for a dial indicator and measured about 0.040 with the 12-6 o'clock play test. Less play at the 3-9 o'clock test, guessing 0.020 (didn't measure). Brake on or off, in gear or neutral, play is the same. Way out of spec (max 0.020) it seems, so I suspect it needs rebuilding or replacement.

Is this impending doom, or can I get more riding in this year and get the FD rebuilt over winter? What would you K bike guys do? Any other suggestions?

[Lowndes]

Find a good used FD on the web and install it ASAP.  You can then look at/decide what to do with the OEM part, repair yourself or send it to someone who can.  It won't be getting better and a FD swap is 45 minutes on the centerstand for my old oil heads.  Can't be too much different for yours.  Watch some Youtubes on your FD.

 

There may be several models with the same FD.  Look up your part number on Bob's BMW (http://www.bobsbmw.com/), get the PN, look at similar models with the same FD PN, including the gear teeth counts.  When you search for a used FD, list all the different models and years along with the part number.  Most people listing such parts/assemblies only list the bike make/model/year it came from, not all the models it will fit.

[dirtrider]

15 hours ago, syntorz said:

Looking for same help over at k-bikes.com.

 

2011 K1300S 25k miles

Noticed some play in the rear wheel at last final drive oil change. Drain oil came out clear, no particles or metallic sludge like other's pics I've seen, but then again I didn't look real close. Probably put on another 1500 miles since then.

So after reading many many stories about GS and RT final drive problems, decided I'd better look into this more. First thing I did was dismounted the brake caliper and spun the rear wheel. Didn't pick up any unusual noises or sensations. I made up a quick-n-dirty base for a dial indicator and measured about 0.040 with the 12-6 o'clock play test. Less play at the 3-9 o'clock test, guessing 0.020 (didn't measure). Brake on or off, in gear or neutral, play is the same. Way out of spec (max 0.020) it seems, so I suspect it needs rebuilding or replacement.

Is this impending doom, or can I get more riding in this year and get the FD rebuilt over winter? What would you K bike guys do? Any other suggestions?

Morning syntorz

 

You might be (probably still are) within specifications. 

 

If it  was a bearing issue then the play SHOULD be exactly the same at  12/6 as it is a 3/9 o'clock so if you have more play at 12/6 then part of the movement is probably in the swing arm pivot bearings.  

 

The BMW service spec is .5mm (.020") max movement measured at the wheel RIM with the final drive temp being under  35°c (95°f). 

[syntorz]

My measurement was at the outer edge of the wheel rim, cold. My setup wasn't machinist-level precise but pretty sure I'm outside of 0.020".

 

Seems used K1300 "S" FDs are rare, and unique to this bike from what I've checked so far. I'll check Bob's. And start investigating if this is a DIY job for me or a dealer visit. Or maybe I can get my machinist bro-in-law to assist.

 

Thanks all.

[syntorz]

Sorry dirtrider, I didn't read your reply close enough to understand fully. I'll check play at 3-9. How do I determine if swing arm pivot bearing play is contributing to my measurement at 6-12?

[dirtrider]

11 hours ago, syntorz said:

Sorry dirtrider, I didn't read your reply close enough to understand fully. I'll check play at 3-9. How do I determine if swing arm pivot bearing play is contributing to my measurement at 6-12?

Morning syntorz

 

Mount your dial indicator as firm as possible to the solid mounted caliper mounting bracket (that is firmly attached to the actual final drive).

 

Then set your dial indicator up to measure on the wheel rim as close as possible to the mounting base (that gives less flex in the mounting system). Try to keep the mount attachment as close as possible to the wheel rim (you don't want any flex in the indicator mount to the indicator itself). 

 

Then mark the wheel rim in 4 places-- 6 o'clock, 9 o'clock, 12 o'clock,  3 o'clock (I use a  yellow China marker) or just guess at 4 evenly spaced measuring points on the rim based on valve stem location. 

 

Then measure the rim movement vs the caliper bracket in those 4 locations  by spinning the wheel one 1/4 turn & re-measuring  (turn the wheel do not move the dial indicator). 

 

 

 

 

 

 

 

 

[syntorz]

Ok, I set up using the service manual and those instructions, dial indicator at 6 o'clock.  With hand grabs at 12-6, checked every 90 degrees of wheel rotation, I'm at 0.030. Not good.

 

I have a (hopefully good) used FD on order and will work with bro-in-law to repair this one provided I can get parts. Stay tuned for more help requests...

 

Im curious what a brand new FD would or should measure? Anybody know?

[dirtrider]

15 minutes ago, syntorz said:

Ok, I set up using the service manual and those instructions, dial indicator at 6 o'clock.  With hand grabs at 12-6, checked every 90 degrees of wheel rotation, I'm at 0.030. Not good.

 

I have a (hopefully good) used FD on order and will work with bro-in-law to repair this one provided I can get parts. Stay tuned for more help requests...

 

Im curious what a brand new FD would or should measure? Anybody know?

Evening  syntorz

 

A new final drive play is pretty well dependent on the bearing +/- within the C specs, the size of the side cover bearing hole, & the OD of spool. 

 

I have seen them run (new 1200RT motorcycle)  to the tight side at "0" play & those seemed to fail the bearing early in life, I have seen them at .025" & live a long healthily life, & seen them about anywhere in between. 

 

Your drive will probably live on without issues at .030" if it spins smooth, & no other issues. But if you want to tackle it then probably a new bearing & seal & "O" ring will be all that it needs (the spool free floats so no shimming required).

 

Easy to replace the bearing & seal IF you can get the wheel/rotor flange off (needs a little heat & a special made puller), putting the flange back on is the hard part as it needs to be heated then slid ALL the way on the spines quickly & smoothly as once it starts to cool it will stick part way on.  

 

 

[syntorz]

Someone put me on a good used FD from eBay and I'm in the process of installing it now.

 

The 'screw' seems bound up in the 'bearing stud' (service manual terms). Unthreading takes a lot of effort and binds up about a third of the way out. No real corrosion I can see, but I did squirt some pb blaster in there. Shouldn't be this hard to get that apart. Is there Loctite in there from the factory? Advice from anyone? 

[syntorz]

I did finally get it unthreaded. Looks like Loctite or pink equivalent on threads. 

[EdM]

My experience on my 08 K1200GT several years ago left me skeptical of the specs for free play on the FD. I noticed mine had minor free play and measured it as per the factory manual and found it well within the tolerances. Just over a thousand kms later I was hauling it home in the back of a rented Uhaul. The large bearing completely failed and left me stranded. I ended up having to replace the entire FD as the bearing slipped on the shaft and damaged it. The shaft is integral to the gear set and is not available as parts, only as a complete FD unit. So, in my mind, any detectable free play warrants replacing the bearing before it fails. The bearing is a bit of a job to replace, but within the scope of a moderately skilled home mechanic with access to the right tools. FWIW, the new replacement FD has lasted far longer than the original and has zero free play still.

[Beech]

Old thread but yes there is loctite in there. It is good practice to heat it first at least 220*F. It is possible to destroy the threads with hard loctite. This bearing journal, the forward one is set at 7Nm after first going to 20Nm. But I have found 9Nm works better. Mark the journal and the case so when tightening the lock ring you can see if anything moves. even a little do it again.