The noise disappears soon as the clutch is pulled in. Rolling in neutral with clutch out reving the motor will not make the grinding sound worse. Sounds a little rocky in neutral ,but soon as it's under a slight load all hell brakes loose with a nasty rhythmic rumble/grinding sound. Trans shifts perfect. Oil is new & full. Sounds too bad to be the push rod bearing.

Anyone had a similar experience with a oil head 6 speed? I'm tearing into it to check the driveshaft first . Let you all know what I find.

Bummer,It's not a bad u joint. To easy. Really don't think it's a clutch problem either. The sound stops when the clutch is pulled , but that means the input shaft unloads and stops spinning to. The video is a little deceiving. I was trying to recreate the sound by applying some rear brake in gear to simulate a load. The sound of the trans teeth rattling overshadow the cyclic rumble that is best heard in the last 25 seconds of the recording. This rumble is much worse under load and sounds like a bearing running with no lubrication. The sound has me convinced it's a trans shaft bearing. Beginning to wander if this leak has something to do with it. Input shaft bearing perhaps?

No choice now but to pull it off and open the tranny and have a look.

Quote:

Originally Posted by JimVonBaden Just to be clear. In gear? Clutch handle released? Was it on the center stand with the rear wheel free spinning? Does it do it under load? Does it do it with the trans in neutral and the clutch handle released, pulled in? Jim

The video shows the bike on the center stand, wheel spinning in first gear. It is normal for the trans to make allot of noise under this condition, but not on the road with a steady smooth load. When the bike is in neutral , it really isn't to noticeable. Put the bike in any gear and apply a load from slight to full out ,and it is a horrible , unmistakable cyclic grinding . Sounds like choo choo choo choo.... Speeds up with road speed. Pull in the clutch and it all but disappears.

Completely convinced that it is a trans shaft bearing. I hope I can find evidence when I open the trans. It started while riding this weekend. By the time I was sure I was hearing something wrong and pulled out the earplugs to confirm, I was 75 miles from home. Rode it back with no issues except the grinding. Pulled the black magnetic drain plug on the bottom of the trans to find it filled with fine metallic fuzz, but nothing any bigger. I never pulled the magnetic drain plug before and I wished I had. So if you have a 1150 , do yourself a favor and clean it off next service. I think the bearings in the trans are sealed (?) which means any grindings should stay in the bearing. The leak at the clutch housing has been there for 15,000 miles. Figured it to be a rear main because I could not detect any gear oil smell. Will find out for sure tonight

Looks like the rear main is not the source of my leak.

The trans input seal on the other hand...

Bike shifts fine. Splines look OK in person. I did a spline lube at 35k. At 55k the splines are dry again, even after using the Honda molly 60. The spline wear looks about the same as before.

With the trans pulled and cleaned it's time. I use a long drift to drive out the two pins where the two halves of the trans mate. I heat up the case first to loosen them up a bit and add a little penetrating fluid. They take a considerable whack to move so the heat seems like a good idea even though the manual makes no mention for this step.

Next order of business is to heat the bearing points in the rear cover. I use two heat guns for 15 minuets. No soup yet.

This laser temp reader takes out the guesswork.

I start heating the front case.

And heat some more. and some more. It shows 205 but my hands are to oily to grab the camera.

Around 220 degrees the input and output shaft bearings are moving easy ready to drop out. The intermediate shaft will not budge. I go at it for a hour and a half with temps up around 230 with no luck. I'm getting frustrated so this round is lost.

Chinese takeout intermission.

I consider my options

1. Put the trans in the oven and bake until the shafts come out, or clouds of smoking gear oil attract the fire company.
2. Make up a jig and pull it out while hot.
3. Give the heat guns another try.

I concentrate all the heat on the intermediate shaft. 260 degrees and still no give. I support the intermediate shaft by holding it in one hand with a set of gear puller jaws. I elevate the entire assembly off the bench and ,not wanting to play it too safe , give the back of the bell housing a few whacks with a rubber mallet. Finally it relents after a dozen or so soft blows.

All three front bearings show signs of disscoloration , but only the intermediate feels bad.

Output shaft.

Input shaft

I never removed the black magnetic drain plug on the bottom of the trans before because the cat. needed to come off to gain access. I found a short 3/8 bolt that has a 9/16 hex fit's perfectly. I put on two nuts and used a wrench to remove the plug with the exhaust in place.

I would soon find out that despite the service manual making no reference to remove and clean this plug for normal maintenance, not doing so was a major blunder on my part. The plug was absolutely filled with super fine metallic fuzz. I cleaned it up , refilled the trans and decided to take the bike for one last ride around the block to listen to the grinding noise one more time and to shoot the video. I should mention I drained the final drive just to make sure That the noise wasn't being transmitted somehow to the trans. Nothing at all was found on the drain plug.

Here is a picture after I cleaned the trans plug once already. I rode the bike less than a mile and managed to pic up this much more debris!!!

You can bet that this will be coming out at every service from now on!

This is what was recommended by the dealer. I normally use what is called for in the manual. I already was using the 75/140 before I discovered the fact that it calls for 90w. This issue has been debated here before.

Over the years , The container has been changed but what came out looked the same. BMW's latest lubricant is now red in color where the old stuff was the normal gold/brown color.

So I'm left wandering why shit happens. So what do you think?

• • The fuzz in the oil found it's way into the bearing and destroyed it.
  • The large amount of fuzz is from the bearing failure
  • The bearing was improperly shimmed at the factory, but took 55k to fail.
  • The catalytic converter's excess heat played a role in cooking the bearings.
  • Changing to the red oil did it!!!
  • The case is improperly machined , hence the reason the bearing would not come out while all the rest were falling out at a much lower temp.
  • Shit happens

Sounds good! But were not in the clear yet. If I screw up ,it could turn out to be the HoW NoT to do it This is only my second transmission job and my first on a beemer , so I am no expert by any stretch.

I spent some time thinking if I should take the transmission shafts to a dealer and have them swap the bearings. After careful consideration, I ordered a shop press and a bearing separator kit. Also in the works will be a way to drive the seals home properly, penny tech style.

Quote:

Originally Posted by johnjen I've been involved with several tranny rebuilds. They were all on airheads but the basics are the same. That isn't to say there won't be specific differences... One, if not the most signifigent aspect of tranny rebuilding is getting the shimming done properly. We developed a method where we dialed in a tranny and the differences are amazing. Most won't/don't want to go to the trouble/time spent to get this one aspect 'just right' but when you do the tranny shifts like a japanese gear box. Well actually like a german box with the snick-snickability of the japanese xmissions. I can wait till the project is 'done' before we immoralize it for all posterity JJ

My plan for shimming consists of carefully measuring the assembled length of the existing shafts. After the bearings are removed , I will compare them to the new ones as well. This should hopefully result in me being abel to match the same size that came out.

One big assumption here is that they were shimmed properly to begin with!

This is uncharted territory for me so any knowledge or suggestions would be greatly appreciated.

Thanks to all for your encouragement and kind comments.

• 07 R1200GS Adv
• 98 FLHR
  
• 95 R100GSPD Classic
• 93 R100GSPD

I set up a dial indicator to measure the overall length of the assembled intermediate shaft. I get repeatable results with this method. I also used a digital caliper to measure overall length ,but found the results to be too varied to fully trust.

The manual gives no absolute overall dimension for the shafts, and no inside dimension for the trans case. Just a .002 figure that I assume is endplay. Without the factory jig ,I can only compare what I had to what I have now.

Here is the procedure I used for installing the bearings. I start by using a washer to absolutely guarantee that no force is exerted on the outer race.

I freeze the shaft and use a heat gun on the new bearings. When the bearings hit about 150 degrees, I carefully line up everything in the press. It is easy to feel when the bearing is fully seated.

I follow the same procedure as before and wind up with similar results. About .006 shorter overall.

This should read zero , the bearings are the same size. ?? ?? One step I failed to take was making sure the old bearings were pressed fully home. It's in the manual ,but I neglected this step. It's the only possibility I can think of. I'm very confident the bearings are the exact same size.

Old bearing

New bearing

This can't be good!

This is the Thrust block. Check out that nice crack on the left ear! I suppose it could be just a gouge, but it extends to far to be from some debris getting in between the mating surfaces. It is on the power side. Their is just no way this can go back in.

The clutch disk splines look a bit worse

I decide that replacing just the disk will accelerate the wear on both parts with their mismatched matting surfaces, so it makes sense to replace both while the trans is apart.

Old disk

New disk

Left one is the culprit. You can see that the sealed bearing is out of it's lubricant. The seal shows metal shavings from the failure. Middle one is same (made in japan) bearing as left, also looking like it has some shavings and not much of whatever it is they pack these with. I do see what looks like ,the red trans fluid on the bearing cage. Maybe the synthetic penetrates the seal and dilutes the grease? The last on right is a output shaft bearing made in England. Looks like it has much more lubricant left then the other two.

[IMG][/IMG]

I made the decision to install the seals in the cases before hand. The depth of the rear output shaft seal is critical as their is a oil hole that could be covered if its driven in a few mm too far. Installing the seals first means that caution must be taken when heating the cases that the seal is not directly exposed to the blast of the heat gun. I used sockets as a shield. I also covered all the splines with a plastic wrap to protect the seals during assembly. I used gear oil sparingly.

Thanks. The problem wan not being able to use the proper size pin due to having to cock it in the bore because part of the trans case is in the way. This resulted in the punch nicking the case, visible at the top of the pin. Was a Harbor Freight punch by the way.. Ill apply the appropriate kink next time.

The only way I could think of to measure the 6 speeds bores is with adjustable mock transmission shafts that could be used in conjunction with plasiguage to arrive at the ideal number. The manual calls for no more than .002 deviation from a end play value it dose not give.

With no current means of manufacturing some homemade mock shafts that would be accurate at those tolerances, I decided that if the bearings are exactly the same as what came out , then that is my better bet then to base shim size on inaccurate information.

When the shafts and shifting mechanism are installed ,I apply the Locktight 515 to the front case. I heat the rear case and slide it home paying attention that the seals are started properly. Torque the case bolts in a crisscross manner and drive home the two drift pins last. I let the gasket sealer set before filling the transmission with gear oil.

[IMG][/IMG]

To complete the mid life refreshing, here are the parts that were replaced.

I put a dot of silicone to make it essayer to confirm I have the Driveshaft phased properly.

Doing some preventive maintenance , I decide to clean up some of the rust on the clutch line where it commonly rusts. Well I got a little ham fisted with the Harbor Freight air angle grinder and nicked the case, oops. $$$

When I first rode this bike , I thought the clutch action was a little grabby. After a while it worked very good. I was worried the new clutch plate might be grabby until broken in. That isn't the case as right out of the box the clutch has very good feel without a hint of gabbiness.

I also made a switch to synthetic dot 4 in the clutch. Putting it in the brakes next.

So only a few hundred miles so far , but everything is dry and sounding good.

In the end , I am assuming the failure stemmed from the bearing using up all it's lifetime lubricant.