R1100GS final drive bearing

[West coast gser]

Well looks like the fd bearing is on it's way out...dreaded silver flakes in the oil ...would've thought it would last longer than about 16,000 miles..all previous parts were from Motorworks..how long should these bearings last ? ...jus as well I've got a spare bearing ,seal and o ring..I have no idea if the one I changed out was the original or if it had been replaced before...I've used semi synth 75/90 gl5 oil and changed it at the required interval..still a bit pissed off to replace it again so soon...

 

[mikeyboy]

There are 4 bearings in the final drive,it may not be the crown wheel bearing that’s degrading.
I’d suggest,if it has failed after 16k miles that something may be amiss with the shimming.

 

[DrFarkoff]

Well looks like the fd bearing is on it's way out...dreaded silver flakes in the oil .

Wee question for you Is it Alloy or Metal flakes

I had one a few years ago and the rear bush for the drive pinion of the drive had eaten through the alloy part

I have a couple of FDs here if you need parts

Edit Linky to the alloy one

I have stopped using the 75W90 in Final drives I now use the 85W140 GL5

Another question did you use GL5 only spec oil ?

 

[West coast gser]

Wee question for you Is it Alloy or Metal flakes

I had one a few years ago and the rear bush for the drive pinion of the drive had eaten through the alloy part

I have a couple of FDs here if you need parts

Edit Linky to the alloy one

I have stopped using the 75W90 in Final drives I now use the 85W140 GL5

Another question did you use GL5 only spec oil ?

Hi ..I would assume it's metal as it was stuck to the magnet on the drain bolt..yeah only GL5 is used ..I may pay that bit extra and get some decent oil..the oil I'm using is Halfords semi synth 75/90 GL5 ..which is the correct spec ...

 

[West coast gser]

There are 4 bearings in the final drive,it may not be the crown wheel bearing that’s degrading.
I’d suggest,if it has failed after 16k miles that something may be amiss with the shimming.

Hmm..I thought there was 3 ?big bearing,taper roller on end of hub ,and a bearing on the final dive where it joins the propshaft..(dunno what its called ) pinion? ..would the taper bearing if it was worn cause the big bearing to go..?

 

[Slipperyeel]

Hmm..I thought there was 3 ?big bearing,taper roller on end of hub ,and a bearing on the final dive where it joins the propshaft..(dunno what its called ) pinion? ..would the taper bearing if it was worn cause the big bearing to go..?

There's 4. At the end of the pinion shaft there is a little bearing. Can't remember if it's a ball race or needle type, but that pinion shaft is effectively supported on both ends

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[Slipperyeel]

Wee question for you Is it Alloy or Metal flakes

I had one a few years ago and the rear bush for the drive pinion of the drive had eaten through the alloy part

I have a couple of FDs here if you need parts

Edit Linky to the alloy one

I have stopped using the 75W90 in Final drives I now use the 85W140 GL5

Another question did you use GL5 only spec oil ?

Doc, how come you switched to 85W140? What's your thinking on that? Interested!

Sent from my SM-G975F using Tapatalk

 

[West coast gser]

Jus been to bike shop n got silkolene boa 80/90 GL5 gear oil so will refill later once drained n checked if there is anymore flakes after my run last nite of 70miles

 

[mikeyboy]

Jus been to bike shop n got silkolene boa 80/90 GL5 gear oil so will refill later once drained n checked if there is anymore flakes after my run last nite of 70miles

Flakes of metal in the drive oil are a pretty bad thing,
They were not put in there by you so must be coming from the internals,why are you still using it?
One thing is certain,it won’t fix itself

Edit
The flakes of metal are almost certainly coming off the input pinion needle roller bearing.(the small one at the end of the input shaft)
Once it starts to deteriorate it will break up and scrap the drive

 

[mikeyboy]

Doc, how come you switched to 85W140? What's your thinking on that? Interested!

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I’m no expert on oil ,but,
The the thicker oil has a higher shear resistance,the helical gears will not chop it up so much.
They use this stuff in heavy truck boxes etc.
An example would be cam failure on 80s jap bikes,sharing oil with a gearbox and engine components didn’t end well if regular oil changes were not carried out.
Going back to our bevel drives,they only hold a small amount of oil,the helical gears cut the oil up eventually, the small needle bearing will suffer due to lubricant failure.

 

[West coast gser]

Flakes of metal in the drive oil are a pretty bad thing,
They were not put in there by you so must be coming from the internals,why are you still using it?
One thing is certain,it won’t fix itself

Edit
The flakes of metal are almost certainly coming off the input pinion needle roller bearing.(the small one at the end of the input shaft)
Once it starts to deteriorate it will break up and scrap the drive

Drained the oil yesterday and there was a few flakes..not as much as before..also gave the gearbox an oil change ...fek..in the oil pan there was like bits of a bearing cage...looks like a new gearbox for me..fek...I had read that the m97 box eventually goes and one of the gears eats into another with the roller cage at anywhere between 50,000 miles + mines has 74,000 odd

 

[Paul G (BHT)]

I've fitted a few of these.

Fit them wrong and they will last a very short time, fit them correctly and they should last at least 40k miles.

Did you heat up the bearing before dropping it on to the crown wheel? Did you heat up the casing before dropping the crown wheel and bearing into it?

If you had to use any force to get all the parts together? Doing so will result in excessive side load on the bearing.

 

[West coast gser]

I've fitted a few of these.

Fit them wrong and they will last a very short time, fit them correctly and they should last at least 40k miles.

Did you heat up the bearing before dropping it on to the crown wheel? Did you heat up the casing before dropping the crown wheel and bearing into it?

If you had to use any force to get all the parts together? Doing so will result in excessive side load on the bearing.

Yes heated up bearing and cover ,also had crown wheel in freezer ..dropped bearing onto it with a satisfying plink then zzzling as it cooled...but got other issues now seems a bearing cage in the gearbox has started to break up ...