GVR4 Tranny rebuild. Difficult?

[curtis]

the best way to pull the bearing that Ive found is a 2 x 12 pine board on the floor. Just hold the propane torch to the bearings to heat them up then start slamming the f&*( out of the shaft on the end. the wood will keep the threads from getting damaged. Just wear gloves the gears are hell on your hands. When it gets close to the end just hold a 1/2 inch deep well socket against the end and finish it by tapping it off.

 

Would a 10ton bearing press do the job too?

 

quote:Originally posted by spoulson:
I managed to get past the stuck roller bearing. Using a 3" pneumatic cut-off wheel I was able to make grooves on both sides so that the crappy bearing separator could grip it and they both finally came off.

Grooves


I hate you!


New parts from TRE


All for now.

 

Sorry, I clicked to early on that last post.

I rebuild these all the time and for that input shaft bearing I use an air hammer with a thin blunt bit placing it between the gear teeth, at the same angle as the gear teeth and push it off catching the edge of the bearing until the bearing spreader can fit. Takes about 10 seconds and your done.

I use a long jawed puller along with a bearing spreader and a step plate set so you don't damage anything for dissasembly, no press needed...

I use a Walmart hot plate to install all bearings. They just drop on with a little heat but don't cook them just warm them, no press needed...

 

[spoulson]

quote:Originally posted by Mariner31:
Would a 10ton bearing press do the job too? Probably, but more importantly you need the space to fit the shaft.

 

[GVR-4]

All but two of my parts arrived today from TRE: an intermediate shaft bearing and the 1st/2nd gear shift rail. These two items were overlooked and will be shipped out Monday. Here's the list:

Four spider center diff, double synchro 1st and 2nd gears, input shaft, steel shift rails, shift forks w/bronze pads, 3rd/4th gear synchro ring, neodymium trash magnet, oil filter, magnetic drain plug, all needle bearings, all roller bearings, roll pins, snap rings, synchro springs, shaft end nuts, all seals, 10% taller 5th gear, and the nylon block for the shift linkage (which I don't need: I machined a brass one).

After $1,886.90, this thing better shift like buttah and NEVER need another rebuild. At least as long as I own it.

Here's a photo:

 

[spoulson]

I spent some more time tonight on the thing. I got the shafts completely rebuilt and ready for assembly.

Now I'm stuck on two things. Maybe someone has some tips to help me along.

I'm removing the old seals: front diff left/right, input shaft, and rear output shaft. the rear output shaft just fell apart and that's a problem because it's a U-shaped seal that wedges into position in the bell housing. I scraped and scraped, and there's still rubber stuck in the groove that won't come out. Tried a torch too, but that made no immediate progress and I was afraid it might just make things worse.

Also, I can't get the input/intermediate shaft bearing races out of the bell housing side of the case. I also tried torching around the outside of the race and pryed with a screwdriver on the intermediate one, but no budge. The input shaft is harder, because there's no place to pry at. Should I just bake the whole thing and hope they'll pop out? The races on the other side weren't much of a problem. And before you say, I can't reuse the races because seems that I'm using slightly different bearing sizes that aren't compatible with old races.

btw, I found this truck parts place that'll do hot tanking, solvent bath, and whatever else. They have a machine shop in the back with all the stuff. Tomorrow I'm going to see what they can do for my ugly trans case.

 

[GVR-4]

Shawn-

I'm not sure what you mean on the output shaft seal. Mine just presses in from outside the case and it's one piece. Maybe you could elaborate or take a photo of what you're talking about.

As for the input shaft race, I just got mine out last night. It was tough. I have two pretty nice Proto gear pullers and I used the legs from the bigger one to get behind the race and "lift" it out. I can send you the pieces of the puller I used if you need them, or at least post photos of what I'm talking about. It's been a while since your post (sorry, I must've missed it) so you've probably got everything worked out by now.

What I lack now is an input shaft C-clip, an output shaft seal, a 1/2 upgraded shift rail (from Jon at TRE, who won't return my e-mails!), and some spacers. After I get all that, I should be golden!


Edit: I'd also limit the amount of heat you put on that aluminum case. Just my $ .02.

dp

 

[spoulson]

Ok, so you press in the output shaft seal. Now when you want to remove a 12 y/o seal, how do you 'un-press' it? It just falls apart and rubber is now wedged into the O ridge where the seal goes. You can't press a new one in because of the rubber that's stuck in there. Got me now?

As for the races, I'm going to give the case pieces to a local guy who I found has a hot tank. Hopefully the races will fall out for me, which can save me some frustration. If not, I got a couple ideas. Nate Pharr suggested for the input shaft race to use a small pry bar or something under the race, then use a 1/2" extension in the input shaft tunnel and bang the extension against the pry bar with a hammer, moving the pry bar around as necessary.

 

[spoulson]

A quick update for the records. I finished the trans and got it back in the car a few weeks ago.

Initially, it drove well but shifted extremely tight. I often had to row the shifter back/forth in different gears to get 1st to go in. Reverse required me to disengage the clutch slowly to go in. 3rd had a minor grind/crunch going in at or above synchronized engagement rpms. I later determined this is because I must have mistakenly overshimmed the shafts, causing them to not move freely to allow easy movement.

My solution was to readjust the shims. But, I really didn't feel like pulling the trans again. I ended up doing the job with the trans on the car. It was not very difficult doing it this way at all.

After reassembly and a little time for the axle sealant to cure, I refilled the oil and gave it a test drive. MUCH better. Now it drives like stock.

Lessons learned:
[*]It is possible to rebuild the trans while on the car. I would not recommend this the first time doing trans work, as you can't study it like you would on a workbench.[*]When doing the on-car trans tear down, removing roll pins from shift rails can be difficult with not much room. I found that a few nails I had laying around fit the diameter perfectly if I cut them shorter and used a regular hammer to drive the pin out.[*]I really need a small gear puller that can pull off the 5th gear from the shaft by the ledge around the top of it. Doing it with prybars just chips the edges of the teeth.[*]Putting oil in the transmission and transfer case can be difficult and messy without the right tools. I came across an inexpensive Mityvac Fluid transfer pump at Pep Boys. One tube in the bottle and the other in the fill hole, then you pump it without getting any junk on you in the process.[*]When installing the oil filter screen, I was initially stumped as to how to install. There is an obvious location on the case with little dowels sticking out. Put the filter there and hammer the dowels flat.[*]If you don't use them already, cardboard boxes are you friend when working under your car.[*]My garage still smells like gear oil.[/list]

 

[GVR-4]

Nice. Mine's been done for a few months too. I am having the same problem you described: tight 1st and 2nd and slight grinding in 2nd and 3rd. I guess I need to set the bearing preload lower. The spec for the solder crush test gives you a range of +/- .005" if I remember correctly. I tried to set it right in the middle. Now it seems I should have set it a bit on the loose side. I think I'll try re-torquing the case bolts 1-2 ft. lbs. less than spec before I tear into it again. I was hoping for better shifting than this. Thanks for the tips, Shawn.

 

[spoulson]

I'm not convinced case bolt torque is a major factor of preload. I always reassembled with a torque wrench in a star pattern in stages until all are ~25lb/ft.

As for loose shimming, don't go too loose. It may seem ok, but whatever that limit is, you don't want to allow for too much lateral movement in the shafts. This may break shift forks, which are fixed in position and cannot move much with the shaft.

It seems to me that shimming is a practice that needs to be perfected over time. My shims were measured out to be larger than the biggest you can buy. So, I got two equal-size shims to total the size I needed for the input/intermediate shafts. So when I realized it had to be too tight, I removed one of those shims from input/intermediate each, thereby halving the shim size. I am probably a little too loose and I will have to re-measure the endplay some day.

 

[GVR-4]

quote:Originally posted by spoulson:

It seems to me that shimming is a practice that needs to be perfected over time. Yeah, I agree with you that it seems to boil down to trial and error. But it sure is a drag that we have tear the tranny apart every time it's not just right.

 

My tranny pops out of first gear and grinds horribly, nearly impossible to use. checked most of the easy external things, im narrowing it down to something inside the tranny... I'm a noob, and i would like/desperately need help and pointers. This looks like a great thread, keep it going.

thx, Joe

 

I got the tranny dropped!!! woot. Well, I'm happy, and now i can do what i need to get a better shifting tranny in there.