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View Full Version : Mini Truck Transfer Case Gears, Flywheel and Clutch


RicardoJM
12-07-2009, 10:53 AM
This past saturday I met Issac V. and Tom R. at Randy's place to do some wrenching on the Geko. The objective for the day was to drop the transfer case and get the 4.70 gears installed into it. Also we ended up putting in a new clutch & flywheel at the same time. There was no leaking from the rear main seal, if there had been we would have taken that on as well.

With four guys and plenty of opportunity to turn a wrench, the picture taking was a more of an afterthought than a focus.

When we arrived, Randy had already been at things for a bit and there were not too many things that needed to be removed to get the transmission and transfer case out. Here Issac is taking care of the shift levers.

http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_issac1.jpg

The top nut on the starter is clearly visible but by the time you get your arm down in there, you can no longer see and the angle is such that the wrench can be turned just a little bit at a a time. Working from the bottom is not really any better. Later when we were putting the starter back on, we found a swivel socket and extension combination that worked much better.

Randy's garage is very well equipped. Working with air tools and having extra hands is always nice.

http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_issac2.jpg

In very short order we were pulling on the transmission and transfer case to get them out - but it was not coming all the way loose. Sure enough, we found a bolt on the back side of the bellhousing that still needed to be removed. Upon removal, the tranny and t-cases were placed on some blocks. Tom went to work on seprating the t-cases for the gear replacement.

http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_removal1.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_removal2.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_removal3.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_removal4.jpg

As Issac and Tom went to work on the t-cases, Randy and I proceeded with removing the clutch and flywheel. The pilot bearing would not just pop out with a screw driver. We tried a couple of other approaches without success.

Issac brought to our attention that removing this bearing can be challenging and it is best done with the proper tool. A little driving and in short order the pilot bearing removal tool was procurred from Checker. For specialty tools like this, it often works out well to use the tool rental program at the auto parts store. Basically, you buy the tool, use it and return it for a full refund. Even with the tool, we found it was necessary to put the old flywheel back on so that we had an even surface for the tool to sit on.

We had some burgers from the Stagecoach for lunch and sent Tom back into town for parts. I'm not clear on the details but we ran into an issue with the gear swap on the t-cases; something about grinding a piece off that should not have been ground off.

So while Tom was traveling, Issac put in the new pilot bearing, freshly machined flywheel and clutch kit while Randy held the crank pulley. All bolts were torqued to spec.

http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_clutch1.jpg

Issac, Randy and I put the transmission back in place. It went back in pretty smoothly. With the t-cases off, we had a small bit of oil leak out the back end.

http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_tranny1.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_tranny2.jpg

The way the work was getting done, I only got a couple of pics of the t-case work.

http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_tcase1.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_tcase2.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_tcase3.jpg

During the day, I had a couple of other shots of the guys working.

http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_random1.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_random2.jpg
http://www.risingsun4x4club.org/uploads/MtnTrucker/gekoclutch/w_random3.jpg


Randy, thanks for the burgers and another chance to learn some more. Issac, Tom it was really nice to work with you guys. Did everyone get their signature on the truck? How did the work on the t-cases go?

AxleIke
12-07-2009, 01:27 PM
Tcases went good.

The issue with the part was Tom mistook one of the pictures in the instructions, and had Randy cut off the ears on the shift fork, rather than clearnace it for the new gear. The picture isn't super clear, and it was an honest mistake remedied by a quick trip by tom to Patrol man's to get a new part.

We got everything buttoned up Sat night, so the silicone could dry up. (Used both paper and silicone for a better seal).

Sunday I drove back down and finished the case with Randy, put it back in, got all the shifters on, while Randy put up the driveshafts, and hooked up all the misc stuff.

Tcases work great, but there is a small issue with the clutch/throw out bearing. When we depress the clutch slightly, there is a squealing noise, and when the clutch is out, there is an ocasional squeal. When the clutch is fully depressed, there is no noise.

So, we then swapped the master and slave cylinders, and bled the clutch system. Still squealing. I adjusted the clutch throw so that the truck will come out of gear completely, but only just barely. This still allows no freeplay in the pedal, which is odd. However, if I adjust for freeplay (1/8"), the truck will not come out of gear (IE clutch is not fully disengaging.)

So. Thoughts were that its something funky with the throwout? When the clutch is fully depressed, there is no sound. I also let the truck run for a minute or two with the clutch half way depressed (In N) and let it squeal. Then, we got the noise to disappear with both full engagement, and full disengagement. But still squealing in between.

Red_Chili
12-07-2009, 01:33 PM
I have had chirping from the throwout when the clutch is fully engaged (pedal fully up) which disappears once any pressure is applied. The fork needed a bit of grease at pivot and where it contacts throwout. But your situation sounds different than that?

Hulk
12-07-2009, 01:34 PM
The objective for the day was to drop the transfer case and get the 4.70 gears installed into it.

You put 4.7:1 gears in the t-case? Wow. I didn't know they could go that low.

AxleIke
12-07-2009, 01:54 PM
Yup. You can actually put in 5.0 gears, and inchworm will cut you any ratio you want so long as you can make it fit.

Randy was all grins in double low racing the motor at 3k and barely moving at all.

Red Chilli, Myself, and Tom are all running the 4.7's in the back case with the 2.28's up front. I LOVE 10.7:1 low range, and final crawl of 206:1 reduction.

AxleIke
12-07-2009, 01:57 PM
I have had chirping from the throwout when the clutch is fully engaged (pedal fully up) which disappears once any pressure is applied. The fork needed a bit of grease at pivot and where it contacts throwout. But your situation sounds different than that?

Similar situation, but no, the chirping continues until the clutch is FULLY depressed, and now has dissapeared when fully off. Squeals in between.

AFAIK, we put everything together correctly. I checked Randy's positioning of the throwout and it looked good, the clutch is installed correctly and all bolts are torqued to the factory specs.

Randy did notice that the throwout was remarkable stiff, and, when pressed against the back surface of the tranny input, it wouldn't rotate at all. Perhaps the inner race and the like need a thicker coat of grease?

AxleIke
12-07-2009, 01:57 PM
Also, that kerosene works AWESOME as a parts cleaner. Not so fun on the hands, but ah well.

Red_Chili
12-07-2009, 02:09 PM
Bad throwout bearing? Not what you wanted to hear...

Not the first bearing I've gotten out of a Toyota box that was bad, sadly.

AxleIke
12-07-2009, 02:50 PM
Dunno, maybe. Randy got everything from Marlin, not sure if its a toyota bearing or not?

RicardoJM
12-07-2009, 02:50 PM
Bad throwout bearing?

If that's the case - by way of checking what I've learned; the transmission would need to be dropped out and a new throwout bearing put on the fork?

I know Randy got a jump start on things before we arrived, but second time around it would only be a few hours work - right?

DaveInDenver
12-07-2009, 02:52 PM
You put 4.7:1 gears in the t-case? Wow. I didn't know they could go that low.
I run a 4.7:1 Marlin gear set in my single t-case setup. No way I could have dragged a stick shift truck through the Rubicon without it.















Which, uh, if anyone was looking for something like that, you know, well... As soon as I can find the time it's the next major part that gets removed and sold. Low total miles, low range only engaged for 3 days so far!

DaveInDenver
12-07-2009, 02:55 PM
Dunno, maybe. Randy got everything from Marlin, not sure if its a toyota bearing or not?
Probably was Toyota, although if not directly OEM it was Koyo or Nachi or Japanese-made equivalent from Marlin. It was not a junk Chinese off brand for sure. A bad bearing would not have been my first guess (although not impossible), but maybe there was contamination on the bearing/input shaft sleeve thing, pressure plate or flywheel? Ricardo didn't leave a big greasy hand print on the flywheel did he?

DaveInDenver
12-07-2009, 03:23 PM
Just a thought, did the machine shop machine the lip on the flywheel or did they machine it flat? Without the lip the clutch would not fully engage and might be slipping a little. As per Marlin I had Havana machine my step at 0.026", which is a little different than the stock step of 0.015". I'm just running a stock Aisin 900 lbf clutch, though, not Marlin HD.

Also wonder if the noise could be the pilot bearing?

Red_Chili
12-07-2009, 03:37 PM
You put 4.7:1 gears in the t-case? Wow. I didn't know they could go that low.
Come into my parlor, said the (minitruck) spider to the fly...

If that ain't low enough, is 5.0 good for you? How about 5:1 in front, 5:1 in back? You know, for those times you need to eat lunch and can't find a parking spot. Just put it in first, step out, get your lunch, eat it, and take a 20 step jog to where your truck went?

RockRunner
12-07-2009, 03:42 PM
If that's the case - by way of checking what I've learned; the transmission would need to be dropped out and a new throwout bearing put on the fork?

I know Randy got a jump start on things before we arrived, but second time around it would only be a few hours work - right?

As long as we remove that last bolt :rolleyes:

AxleIke
12-07-2009, 04:21 PM
Just a thought, did the machine shop machine the lip on the flywheel or did they machine it flat? Without the lip the clutch would not fully engage and might be slipping a little. As per Marlin I had Havana machine my step at 0.026", which is a little different than the stock step of 0.015". I'm just running a stock Aisin 900 lbf clutch, though, not Marlin HD.

Also wonder if the noise could be the pilot bearing?

I'm not sure. I've only ever run the stock Aisin clutch as well, never the Marlin one.

Randy will have to chime in with the machined lip. I'm not sure.

AxleIke
12-07-2009, 04:22 PM
If that's the case - by way of checking what I've learned; the transmission would need to be dropped out and a new throwout bearing put on the fork?

I know Randy got a jump start on things before we arrived, but second time around it would only be a few hours work - right?

You are correct. Don't even need to remove the tranny fully. Just slide it back. Remove the rear and front tcase shifters, and it should slide right backwards and out.

AxleIke
12-07-2009, 04:24 PM
Just a thought, did the machine shop machine the lip on the flywheel or did they machine it flat? Without the lip the clutch would not fully engage and might be slipping a little. As per Marlin I had Havana machine my step at 0.026", which is a little different than the stock step of 0.015". I'm just running a stock Aisin 900 lbf clutch, though, not Marlin HD.

Also wonder if the noise could be the pilot bearing?

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.

Hulk
12-07-2009, 04:39 PM
Come into my parlor, said the (minitruck) spider to the fly...

If that ain't low enough, is 5.0 good for you? How about 5:1 in front, 5:1 in back? You know, for those times you need to eat lunch and can't find a parking spot. Just put it in first, step out, get your lunch, eat it, and take a 20 step jog to where your truck went?

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.

RicardoJM
12-07-2009, 05:18 PM
but maybe there was contamination on the bearing/input shaft sleeve thing, pressure plate or flywheel? Ricardo didn't leave a big greasy hand print on the flywheel did he?

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

Just a thought, did the machine shop machine the lip on the flywheel or did they machine it flat?

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

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.

DaveInDenver
12-07-2009, 05:37 PM
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
12-07-2009, 05:39 PM
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
12-07-2009, 05:47 PM
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
12-07-2009, 06:55 PM
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
12-07-2009, 09:57 PM
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
12-07-2009, 10:35 PM
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
12-07-2009, 11:16 PM
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
12-07-2009, 11:17 PM
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
12-08-2009, 08:02 AM
Did you get the spring clip on correctly from the TO bearing to the shift fork?

AxleIke
12-08-2009, 08:06 AM
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
12-08-2009, 08:01 PM
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
12-09-2009, 05:36 PM
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
12-10-2009, 09:12 AM
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.