915 pinion bearing race repair
06-15-2016, 11:53 PM
#1
Team Owner
Thread Starter
915 pinion bearing race repair
I have the loose bearing race issue in my 915 Gear box.
Anyone know any places in Canada that can fix this and maybe what their process is?
Thanks guys .
Anyone know any places in Canada that can fix this and maybe what their process is?
Thanks guys .
Last edited by theiceman; 06-16-2016 at 10:20 AM.
06-16-2016, 10:21 AM
#3
Team Owner
Thread Starter
that's an option .
One of the fixes includes chroming the outer race to gain back the friction fit and have a tight fit once again. I have heard this can be a very successful fix so if anyone knows of a chroming place please pass it along.
One of the fixes includes chroming the outer race to gain back the friction fit and have a tight fit once again. I have heard this can be a very successful fix so if anyone knows of a chroming place please pass it along.
06-16-2016, 10:31 AM
#4
I'd give Auguste or Randy/Whaletail a shout...the 'old guard'...
06-16-2016, 08:28 PM
#6
Racer
Join Date: Sep 2007
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Depending on your timetable it might simply be better to send it to WEVO or California Motorsport. They have the tooling and know the grade of metal to use for the insert.
I know that CMS now machines both the pinion and main shaft bearing holes in the case, since they feel that by only machining the pinion bearing hole there is not enough material remaining between the two holes. So they machine both and have a single insert with both holes in it.
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06-20-2016, 09:49 PM
#12
You can glue it, just need to use the right glue. Many people use green loctite but it is not good enough for the gaps typically exhibited. Loctite 660 is a good choice. We've done many gearboxes before, but as Quinlan mentions, WEVO is the BEST solution.
Imre, you can't pin it with a set screw, the bearing retainer plate sits flush with the case on the side it falls out of. Also, even if you pin it, it would still spin with the bearing. The retainer plate holds it in, it's the spinning you need to prevent, but good idea though.
Imre, you can't pin it with a set screw, the bearing retainer plate sits flush with the case on the side it falls out of. Also, even if you pin it, it would still spin with the bearing. The retainer plate holds it in, it's the spinning you need to prevent, but good idea though.
06-20-2016, 10:45 PM
#13
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Clive:
Since it appears that it is still pretty tight, according to your description, then using a retaining compound should work. If the fit is as tight as you describe then there should be little risk of the bearing being installed off center.
In fact, likely less risk than is inherent in having a ring installed.
Probably saves you from having to re-set the pinion.
I'd use Loctite 638 or 680 - both of these are very high strength, and are OK with the temperatures. Look at the specs of these or anything else you are thinking of using to make sure the stuff is good for the application ( fairly high temperatures, high loads).
As a heads up, it is best to think of this as a permanent process - you would have to heat it over 200C to break the bond, and it is no fun trying to push a bearing out of something that hot.
In your research, did you determine the root cause of this issue? It might be that the bearing retainer or even the insert ring approach is only temporary, depending on the cause.
You know, the value of an SC is on the way up, so you perhaps can justify the WEVO sideplates
https://rennlist.com/forums/images/smilies/rolleyes.gif
Are you doing the transmission yourself? What did you do for tools?
Since it appears that it is still pretty tight, according to your description, then using a retaining compound should work. If the fit is as tight as you describe then there should be little risk of the bearing being installed off center.
In fact, likely less risk than is inherent in having a ring installed.
Probably saves you from having to re-set the pinion.
I'd use Loctite 638 or 680 - both of these are very high strength, and are OK with the temperatures. Look at the specs of these or anything else you are thinking of using to make sure the stuff is good for the application ( fairly high temperatures, high loads).
As a heads up, it is best to think of this as a permanent process - you would have to heat it over 200C to break the bond, and it is no fun trying to push a bearing out of something that hot.
In your research, did you determine the root cause of this issue? It might be that the bearing retainer or even the insert ring approach is only temporary, depending on the cause.
You know, the value of an SC is on the way up, so you perhaps can justify the WEVO sideplates
https://rennlist.com/forums/images/smilies/rolleyes.gif
Are you doing the transmission yourself? What did you do for tools?
06-21-2016, 10:42 AM
#14
Team Owner
Thread Starter
Hi Bob its been a while.
I originally just took it apart as I had it on my bench after my engine rebuild and was just going to look at first and second gear synchro. figured I could pop off the shaft , redo it and pop it back on ..
From what I have read about root cause, its just one of those design things and the vast majority of 915s exhibit this when taken apart. I had no indication of failure at all and this might have happened recently and I got lucky .
I measure the outer race od and I get 3.145
I measure the bore and I get 3.145 and I measure them over and over .. I know this is impossible because it actually fell out so it cant be the case, I must have some varience with the tool but does tell you how close it is.
I am going to check the specs on the compounds you mentioned along with jonathons 660 . I would love to be able to go with this solution as it would keep m going with the project . if I strip it down anymore for more complex fixes and I think I may be into more complex measurements of lash and s forth , hell I may already be there.
The only challenge I see so far Bob is tightening those nuts back up on the shafts. I need some kind of locking tool for the transmission. I am looking for an old 915 clutch disk to make one.
I originally just took it apart as I had it on my bench after my engine rebuild and was just going to look at first and second gear synchro. figured I could pop off the shaft , redo it and pop it back on ..
From what I have read about root cause, its just one of those design things and the vast majority of 915s exhibit this when taken apart. I had no indication of failure at all and this might have happened recently and I got lucky .
I measure the outer race od and I get 3.145
I measure the bore and I get 3.145 and I measure them over and over .. I know this is impossible because it actually fell out so it cant be the case, I must have some varience with the tool but does tell you how close it is.
I am going to check the specs on the compounds you mentioned along with jonathons 660 . I would love to be able to go with this solution as it would keep m going with the project . if I strip it down anymore for more complex fixes and I think I may be into more complex measurements of lash and s forth , hell I may already be there.
The only challenge I see so far Bob is tightening those nuts back up on the shafts. I need some kind of locking tool for the transmission. I am looking for an old 915 clutch disk to make one.
06-21-2016, 09:26 PM
#15
Bob - this is a very common problem with the 915. Case block for race was too big, or OD on race was too small... I've only worked on about 5 or so 915's - but every single one has had this issue. I am told that it is a very common problem by people who know things...
