Transmission Question

lockedup5

lockedup5

overcompensating underachiever
Joined
Jan 30, 2008
Location
Burke County (Hildebran)
I've got a Jeep T-18 pulled it from the motor while it was out and noticed it had a little play in the input shaft. Was wondering if the play was normal or if I was going to have problems in the near future. I was going to replace the front seal while I had it out and thought I might be able to replace the front main bearing externally if needed/possible.
What is ya'lls thoughts?
 
Is it side to side play or in/out play. If its side to side a little is normal since the pilot bearing in the crank is supposed to be the third bearing or support for the input shaft. There is a endplay measurement (in/out) but I can't remember off top of my head. The endplay spec is in the thousandths of an inch though, so it won't be a lot of play.

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IME, the input shaft moves around a lot. It's meant to be held at the motor side by the pilot bearing, supported at its end by the input shaft bearing (T18 might even be a conical input bearing??), and there are usually some thrust bearings or something for transferring lateral loads back to the mainshaft. But the connections at the input bearing aren't substantial enough to keep the end of the input shaft from flopping around. So long as there's not lateral play *at* the input bearing, you're probably fine. Input bearing is cheap, though.
 
It's side to side play I'm talking about. I didn't check the in and out but don't think there was any. Just been a while since I messed with a transmission.
As far as replacing the seal I'm assuming I just remove the front plate that goes over the input shaft and it will be there. Do I need to be looking for any surprises like needle bearings falling out or anything?
 
Yes the seal is in that front bearing retainer. If you leave the input shaft in the transmission you don't have to worry about any bearings. If you pull the input to replace the main input bearing there are some loose roller bearings inside the input gear between the input and output shafts. They're not little needles though, like a ujoint. If you do go that far in, clean them good and pack them with vasline to keep them in place for reassembly. Regular wheel bearing grease is too thick and won't break down in regular gear oil like vasaline will.

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lockedup5 said:
It's side to side play I'm talking about. I didn't check the in and out but don't think there was any. Just been a while since I messed with a transmission.
As far as replacing the seal I'm assuming I just remove the front plate that goes over the input shaft and it will be there. Do I need to be looking for any surprises like needle bearings falling out or anything?
Click to expand...

Sent you a PM, and an email.
 
the input bearing can be changed without removing the input shaft.

the pilot bearing (bushing) is not a support for the input shaft. the pilot bearing's job is to slow the input shaft speed down to match the speed of the output shaft.
 
how much play is in the shaft? I had some even after I went through my T18. bearing is cheap and easy to get to now, might as well change it than chance regretting you had later. At least its worth taking out and inspecting
 
Tim C said:
Yes the seal is in that front bearing retainer. If you leave the input shaft in the transmission you don't have to worry about any bearings. If you pull the input to replace the main input bearing there are some loose roller bearings inside the input gear between the input and output shafts. They're not little needles though, like a ujoint. If you do go that far in, clean them good and pack them with vasline to keep them in place for reassembly. Regular wheel bearing grease is too thick and won't break down in regular gear oil like vasaline will.

Sent from my ADR6400L using Tapatalk 2
Click to expand...

I rebuilt a T-150 years ago and I just remember roller bearings falling every where and was a pain since I really didn't know what I was doing
 
Granny said:
Sent you a PM, and an email.
Click to expand...
Thanks Don
rockcity said:
how much play is in the shaft? I had some even after I went through my T18. bearing is cheap and easy to get to now, might as well change it than chance regretting you had later. At least its worth taking out and inspecting
Click to expand...
Not a whole lot seemed like.

transman731 said:
the input bearing can be changed without removing the input shaft.

the pilot bearing (bushing) is not a support for the input shaft. the pilot bearing's job is to slow the input shaft speed down to match the speed of the output shaft.
Click to expand...

When changing out the front main will it just slide out easy assuming it's not a press fit?


I'd probably figure all this all out if I could just get the time to pull it apart. I do appreciate all the info.
 
transman731 said:
the input bearing can be changed without removing the input shaft.

the pilot bearing (bushing) is not a support for the input shaft. the pilot bearing's job is to slow the input shaft speed down to match the speed of the output shaft.
Click to expand...

I don't think we're talking about the same bushing. The clutch plays a bigger role in adjusting the speed of the input shaft than the pilot bearing does. :flipoff2:
 
novacayne75 said:
dont be suprised if you dont find a input shaft seal in a t-18
Click to expand...
B-b-b-b-but Bubba down at the parts house handed me one and said it would fit jjjjust right. :D


I was about to call you crazy and a couple other things till I did about 3 min. of research. You sir are correct! :eek:
It does have something called an oil baffle behind the bearing though. Now tell me how it hold the gear oil from going through an open bearing or is it a sealed bearing?

I guess ole bubba sold me a seal for my flux capacitor or something
 
no prob most people think im a little more than crazy.
some t-18's do have input shaft seals but for the ones without their is a spiral groove cut into the bearing retainer to redirest the oil back into the tranny when the shaft is spinning.
the problem is when you park downhill and shut it off it will puke a oil trail down the input shaft and into the clutch so what i do is drill a small drain hole in the retainer snout about an inch from the end to let the oil run out before it makes it to the clutch.
 
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