Mini Truck Transfer Case Gears, Flywheel and Clutch

[DaveInDenver]

I dunno about the pilot bearing Dave. I mean, wouldn't that make noise all the time. Its always spinning to some degree or another.

Yeah, I agree that my guess is it would squeal all the time, although pushing the clutch does change the load a little. Maybe the engine crank bearings or input bearings are worn enough that it changes the way the pilot bearing is load? Just speculation because pilot bearings can make a lot of noise when they wear out.

 

[AxleIke]

Is there simply more room in the minitruck transfer case for bigger gears? Jim Sanville and I had to clearance the case in my FJ40 just to fit the 3:1 gears.

You do have to clearance the case, but only by about 1/8". Takes about 5 mins with a 4.5" grinder.

 

[DaveInDenver]

My paw prints were on there, but Issac hit it up with glass cleaner and clean rag so that it shined.



The flywheel was machined with the step. I don't know the measurement, but I do recall looking at it with Randy and him pointing out where the step is.



I test fitted the pilot bearing on the shaft. It was not real smooth, so I took a strip of emery cloth to the shaft till it smoothly slid into place.

A couple of things pop into my mind, FWTAW.

I wonder if the glass cleaner could have left any residue? I usually use brake cleaner as the final cleaning of the flywheel. Could also have been contamination on the pressure plate side or even grease being slung around post install.

Ultra smooth input shaft might be slightly spinning inside the pilot bearing? Not sure hitting it with emery cloth could remove enough material to make the interference fit an issue, though. Also not sure how much of this bearing is mechanical loaded (is there a shoulder that touches the bearing inner race, my memory isn't good enough) vs. just friction.

 

[rover67]

Yeah, I agree that my guess is it would squeal all the time, although pushing the clutch does change the load a little. Maybe the engine crank bearings or input bearings are worn enough that it changes the way the pilot bearing is load? Just speculation because pilot bearings can make a lot of noise when they wear out.

The pilot bearing does not turn when the clutch pedal is not pressed (clutch engaged). It only turns when there is a difference in RPM of the flywheel and input shaft.

Edit: From reading it dosen't sound like it's the pilot bearing either way though. IF the noise was not there before I'd suspect other new parts, not the input or main bearings. As far as main bearings go, if they were that worn out you'd be having other issues..

 

[mtnrunner]

Did you add a twin stick to the rear case? Along with the 4.7/2.28 low, the twin stick was the best thing I have added. I went with the Trail Gear twin stick levers. It is a very well made piece. It makes shifting in/out and 2low rear only very easy.

 

[DaveInDenver]

The pilot bearing does not turn when the clutch pedal is not pressed (clutch engaged). It only turns when there is a difference in RPM of the flywheel and input shaft.

That's true.

Then, we got the noise to disappear with both full engagement, and full disengagement. But still squealing in between.

This is a good trouble shooting thread! I'm still liking the throw out, but who knows.

 

[AxleIke]

Marco is right which means its not the pilot bearing. At first the noise was there when the clutch was fully out, not engaged, but that went away after a while. It also disappeared at full engagement.

 

[AxleIke]

Did you add a twin stick to the rear case? Along with the 4.7/2.28 low, the twin stick was the best thing I have added. I went with the Trail Gear twin stick levers. It is a very well made piece. It makes shifting in/out and 2low rear only very easy.

It already had one.

 

[mtnrunner]

Did you get the spring clip on correctly from the TO bearing to the shift fork?

 

[AxleIke]

Did you get the spring clip on correctly from the TO bearing to the shift fork?

I'm pretty sure we did. Can't be positive, but I checked it before it went in, and we checked it against the picture in the Chilton manual. All appeared correct.

I'm pretty convinced its a throw out bearing issue.

 

[mtnrunner]

Sounds like it probably is. Mine made a similar sound before I changed it out. I put the one in from Marlin. Too bad you have to take it all back apart.

 

[Air Randy]

I'm going to drive it a little more to see if the squeal goes away. It's anew TO bearing and it shouldnt make noise but maybe it's just a little tight and a little wear will loosen it up. If not it's no big deal to slide the tranny back and swap it again. If I use two 6" long bolts to replace 2 of the 17mm bellhousing bolts it can slide back on those without a jack and should slide right back together pretty easy.

 

[Red_Chili]

Excellent plan!

I had a couple tensioner pulleys for 3.4 timing belts come bad from Toyota out of the box. One was so bad I caught it before install: dry. Spun it for Jerry at Burt and his eyes got big, got me another one.