Joined: Dec 10, 2017 Posts: 336 Location: Southern Maryland
Posted: Sun Mar 08, 2020 8:00 pm Post subject: 1953 M38A1 T-90A
While inspecting my T-90 input shaft bearing cover I noticed what looks like a thin bearing sleeve pushed into the tube that supports the throw out bearing. This sleeve is at the transmission case end just ahead of the felt oil seal. The sleeve is chewed up like a shaft was spinning on it with embedded dirt. I always thought the input shaft turned free of the throw out bearing tube, so what's this thin sleeve's purpose and why is it chewed up? Note, the input shaft look prefect with no signs of turning or riding on anything...
I also found the Flywheel Pilot Bearing was wallowed out about 1/4" larger than standard, is this normal wear or should I be looking for some other issue while I have it apart?
Thanks,
Mike B _________________ Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer
Sounds like you have a significant amount of prior owner jury rigging. No bushing or sleeve belongs in the front tube of the input shaft cover. The throwout bearing is supported by the ball on the bell housing and it's fork. You clearly need a new pilot bearing and of course you need to check the input shaft bearing for excess play as well. Perhaps you can find someone here on the site with a cover off their tranny that can give you an idea of the input shaft cover's front tube thickness for comparison with yours. It may be that in the past there was a serious pilot bearing wear issue that resulted in a lot of input shaft wobble which may have taken some meat out of your cover's front tube and the sleeve is a jury rigged solution to the old problem. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Dec 10, 2017 Posts: 336 Location: Southern Maryland
Posted: Mon Mar 09, 2020 8:16 pm Post subject:
Thanks for confirming there isn't supposed to be a sleeve/bearing in the tube (I think i'll just knock it out). I know Bubba has been into the trans and transfer cases as there are no gaskets anywhere, just Blue RTV. And I mean RTV in and on every possible leak location...there was so much that it oozed out into the case and got on the bearing surfaces.
The front cover tube looks fine, no sign of the shaft rubbing...it still has the micro machine marks inside from being bored out when made. I'm thinking the PO put a sleeve in to aid in stopping the oil leaks...
Speaking of the oil leaks, do you recommend the new front covers that have a modern oil seal in them to help stop oil from getting into the bell housing? The inside of my bell housing is covered with a fine mist of black oil that looks like it had graphite added (probably clutch dust mixed with the oil)...if you get it on your hands it's hard to get off...
I've also read where a sealed bearing has been used along with plugging the oil return hole...are either of these tricks or maybe both worth doing?
Thanks again!
Mike B _________________ Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer
Joined: Dec 10, 2017 Posts: 336 Location: Southern Maryland
Posted: Tue Mar 10, 2020 2:25 pm Post subject:
Brian, what was found in the bell housing was a very thin layer of black oil that when I got it on my hands would not wipe clean with a rag...reminded me of graphite. And yes, both units are now down to their bare cases and getting lots of new parts, seals and gaskets.
Wes, I do have ORD SNL G-758 as well as the TM-9-8015-2 and the TM 9-8014.
The Felt seal "D" and the Baffle "H" were both in place, but the Pilot Bearing was completely shot and about 1/4" over-sized. So, maybe that felt seal (also covered in Blue RTV wasn't able to do it's job allowing gear lube into the bell housing which then mixed with the clutch dust to make the black oily mess.
Any thoughts on the sealed bearing or bearing retainer cover with the modern oil seal? Worth doing or not?
Thanks!
Mike B _________________ Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer
It sounds like your predecessor fixed the worn out input shaft bearing and left the worn out pilot bearing in the flywheel. If he didn't care about the wallowed out pilot bearing I bet he didn't bother to clean up the old mess.
The 10 or so old Willys jeeps I have owned the past 50 years have done just fine with the stock seal. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Dec 10, 2017 Posts: 336 Location: Southern Maryland
Posted: Tue Mar 10, 2020 9:25 pm Post subject:
Wes, Thanks for the follow up on the felt seal...since I have a new felt seal, that's what I'll use. With all of the things I'm fixing the Jeep has to be better off than it was when I started...
Mike B _________________ Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer
Yep. Usually there is one haunting thought during any restoration: What Did I Forget??? _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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