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Output shaft.
Posted: Mon Oct 24, 2022 12:24 am
by SteveD
https://youtu.be/TlWjCYUP_sE
I’ve dismantled a spare 5 speed circlip trans. Its history is unknown to me.
2nd and 3rd gear have a little pitting on maybe 6 or so teeth. 5th gear is mobile on the shaft but not so much when 3rd is up against it , the front bearing has a tiny amount of movement only but spins nicely. There is a circlip but no snap ring. I have no history of this trans. The case is ribbed, the helical gears don't have the markings of the later ones.
There were no shavings or chunks in the box. Everything looks intact, all dogs look square and unchipped.
Next step will be to remove the front bearing and inspect the shaft.
Any comment on the state of the 5th gear in the video?
- A506783F-DBA7-4E80-BEF2-460F4FE3AB23.jpeg (831.33 KiB) Viewed 762 times
Re: Output shaft.
Posted: Mon Oct 24, 2022 9:57 am
by gspd
Hard to comment without the actual parts in hand.
Is it possible that washer # 6 is missing?
The shaft has longitudinal lines where 5th rotates on it.
Those lines will help you establish how worn the shaft is.
Pitting on gear teeth is never good, but it's not necessarily a deal breaker.
Replace that gear if you can. Wish for the best if you can't.
It'll probably run forever as it is.
The 23 12 1 338 795 bearing FROM BMW, has no taper on it's inside race where it contacts the circlip #2, rendering the wire spring clip #3 obsolete.
Re: Output shaft.
Posted: Mon Oct 24, 2022 10:13 pm
by SteveD
some bloke on advrider wrote:
If the output flange turns freely and smoothly by hand (with the driveshaft disconnected), AND, if the tranny drain plug magnet came out with no crap on it, you're 99% safe until the next scheduled trans oil change.
I also have another spare. Another gfc purchase...those really were the days!
On the bench, comparing the two before I dismantled the one in this discussion:
The output flange turned, but with a slight degree of stiffness but it had 5-10mm of rotation free play. The other one spins smoothly and there's no free play. That difference in feel was why I chose this one to dismantle and inspect.
The pawl springs all look good! Bonus
Re: Output shaft.
Posted: Mon Oct 24, 2022 11:15 pm
by gspd
Lowsy pic. That broken piece is the inside race of the bearing on the spline end of the input shaft.
It comes with this bearing:
https://www.euromotoelectrics.com/produ ... ing449.htm
You have to disassemble the input shaft because it can ONLY come off from the other end.
It's broken because somebody tried to pull it off towards the spline end. I know that because a long time ago, in a land far away...oh, never mind. To remove the outer part of that bearing, remove the input seal from the case, apply a little heat, and the outer part should fall out with just a light tap.
You don't really need any special BMW ($$$$) tools for this job. It just takes a bit longer without them. You do need common sense however; don't force anything. You can pull old bearings you're replacing off by their outside edges, but only apply pressure to the inside races when installing the new ones. If something appears seized, apply a bit of heat. A generic bearing puller kit (and a padded jaw vise to hold things) and a bunch of generic sockets will get the whole job done.
https://www.amazon.ca/Automotive-Bearin ... 3039&psc=1
Have some good pics (like from the MAX BMW fiche) of the shaft assemblies handy and be sure to re-assemble everything in the right order. You'll need a vernier caliper. Have a bunch of shims handy, they're all the same OD and ID, just different thicknesses.
This plate is very useful and will save a lot of time and
I highly recommend it, but it's not an absolute necessity.
https://www.cycleworks.net/index.php?ma ... ucts_id=39.
No plate? I have an unconventional method to end up with perfect end play that will make mere mortals cringe, remember, I am the mechanic from Hell
AND CHANGE THE DAMNED PAWL SPRING, REGARDLESS OF HOW IT LOOKS! It's only $3.00
Re: Output shaft.
Posted: Tue Oct 25, 2022 3:49 am
by SteveD
Ohh yeah, the pawl spring will be changed!
I have a shim plate. My plan will be to assess that output shaft under the front bearing and 5th gear. If that's ok then I'll review costs and decide what to do. My inclination is to fix it with new seals, bearings, springs, 2nd and 3rd gears, maybe a tall 5th but only if that shaft is good enough.
ukp100 from motorworks.co.uk. postage is around ukp45. Less than $OZ300 delivered...add ~ukp40 for the seals and gasket etc...
The gears bump it up substantially.
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Re: Output shaft.
Posted: Tue Oct 25, 2022 6:41 am
by gspd
The bearing kit you pictured has the old style large bearing that requires the spring clip behind the circlip.
The side with the writing on it shouldn't have a taper.
It'll work, but I prefer the other one with no taper and no spring clip.
Re: Output shaft.
Posted: Tue Oct 25, 2022 1:28 pm
by Rob Frankham
Just an observation... not wishing to foment controversy and dissension (much
) but I've never yet found it necessary to replace the front input shaft bearing... they seem to be pretty much bulletproof.
Rob
Re: Output shaft.
Posted: Tue Oct 25, 2022 5:34 pm
by gspd
Rob Frankham wrote: ↑Tue Oct 25, 2022 1:28 pm
Just an observation... not wishing to foment controversy and dissension (much
) but I've never yet found it necessary to replace the front input shaft bearing... they seem to be pretty much bulletproof.
I replaced mine at 550,000km but there was nothing really wrong with it.
I just felt like it.
Re: Output shaft.
Posted: Wed Oct 26, 2022 5:05 am
by SteveD
Rob Frankham wrote: ↑Tue Oct 25, 2022 1:28 pm
Just an observation... not wishing to foment controversy and dissension (much
) but I've never yet found it necessary to replace the front input shaft bearing... they seem to be pretty much bulletproof.
Rob
Yeah, it seems ok but the whole input shaft needs to be dismantled to replace that flange that's damaged. The set of bearings isn't too bad a hit, so ...
...plus I like spares