Transmission teardown/rebuild

[Coyote Patrol]

First i would like to thank robs30m, and Esteban for the transmission bearing part #s. I crossed them to NAPA part #s. You can pull the transmission and transfer case out together, or separately. I pulled mine together, but im installing them separately. This trany/transfer case that you see in the pics was already out and on the ground its a parts tranny that i pulled apart to get these pics for you. First thing you need to do is take the rear PTO plate off the transfer case to expose the main shaft nut. There is a lock washer on the nut, just bend the tab straight and pull the nut and washer off. Next grab the gear and seal race and slide them out.

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Now remove the 4 bolts and 1 nut that hold the trany and transfer case together, and pull them apart.

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here is a shot of the transfer case input seal carquest part # 710345, NAPA part #17758.

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Now pull the shift tower and the front retainer off. The seal in the retainer is a 35/55/8 double lip seal purchased from ebay

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Next you will need to take the snap ring off the input shaft and remove that bearing, then remove the bearing off the rear of the main shaft. These should slide off with little effort. I said with little effort and there is an air chisel in the pic. He He that was for just in case.

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Now you cant remove the input and the main shaft because the counter shaft needs to be moved out of the way. So at this point you will see a nut and lock washer on one end of the counter shaft. You don't have to remove this unless the bearing needs to be replaced. Note this bearing is on very tight, it will need a bearing jaw puller. To move this counter shaft out of the way, just push it in from the other side and let the shaft fall out of the way to the bottom of the case.

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At this point the counter shaft is out of the way so you can now remove the input shaft. The needle bearings will fall to the bottom of the case. Thats ok use a magnet to retrieve them. These needle bearings are 3.00mmX27.78mm or .118"X1.093" there are 24 of them. i have not sourced these good luck. Now pull the main shaft out.

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if you need to pull the counter shaft out you will need to remove the nut and bearing on the one end and remove the reverse idler gear out of the case. I didn't need to go this far because the counter shaft bearings on mine are good. These next two pics are with the input and main shafts still installed. Note the gap where the screwdriver is pointing in the first pic, this is with the main shaft pushed forward, its at least 1/8", too much in my opinion. Now look at the second pic, this is with the main shaft pushed rearward ( this would be the position it would be in with the nut tightened in the transfer case, very first pic of this thread). Im going to add a shim where the screwdriver is pointing in the first pic, im shooting for around 10-15 thousandths of an inch between the input and main shaft. Look at the second pic where the screwdriver is pointing, compare it with the first pic right above it. Note the gap in the second pic next to the synchro, this is with the main shaft pushed rearward. Thats a lot! No wonder these are notorious for grinding gears!

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After it was all said and done, the only thing i found wrong with my transmission was the input shaft pocket needle bearing was bad.(hopefully we can eventually source these), too much clearance at the synchro, the main shaft nut was loose causing the main shaft to float, and i replaced the input bearing. All other bearings looked good. I will finish this thread when i put it back together. Sorry for all the pics, it took this many to explain all of this. Hope this helps.

[jwgreen]

Awesome thread so far!!! Keep it up so we will be able to put it all back together!

[sleepyzzz]

after looking at your pictures, and reading through your post, i feel more confident trying this myself instead of letting the Datsun guy do it. very nice write up and it deserves a sticky for future reference

[RiverPatrol]

Awesome 'how-to', with all the pics it's fabulous. It's now a sticky.

[Coyote Patrol]

after looking at your pictures, and reading through your post, i feel more confident trying this myself instead of letting the Datsun guy do it. very nice write up and it deserves a sticky for future reference

This really is easy, the hardest part of this other than weight is pulling the rear counter shaft bearing off. ITS TIGHT! Hopefully yours is good so you wont have to pull it.

[Esteban]

Excellent Instructions and tips, Ron. Coupled them with your pictures and we can forget the manual for good. Very clear.

Thanks for taking the time to do it.

From what I recall when I have rebuilt my transmissions (mostly my brother did the work) the gap that you pointed out in the picture with the screwdriver was big, but everything seemed to be ok. The last time, before bringing my Patrol into the USA was the same. I only changed bearings, synchros, and seals and it has been ok so far, with 16k miles. In another transmission I did suffer from the problem of the second gear popping out, specially when using the engine to brake in that gear. The problem is that I can't recall what the solution was, or if by changing the second gear pinion (where the synchro engages) along with its bush corrected the problem.

Can't wait for the next installment.

[Coyote Patrol]

Well the pocket needle bearings in my input shaft went bad and destroyed the inner race of the input. I think i might have found a repair roller bearing that might work, also found a roller bearing that might work in place of the original. I have ordered both i will keep you updated.

[sleepyzzz]

thanks Leslie for making this a sticky, and thanks to you Ron for all the trouble of posting your pics and how to tear down and rebuild the tranny. the replacement numbers on bearings, races, and seals are a tremendous help. thanks so much.

[Coyote Patrol]

thanks Leslie for making this a sticky, and thanks to you Ron for all the trouble of posting your pics and how to tear down and rebuild the tranny. the replacement numbers on bearings, races, and seals are a tremendous help. thanks so much.

No problem, you are welcome i will get more pics as it goes back together. Work has got me burning and turning these last few days.

[moore_rb]

Awesome stuff, Ron....

If you left now, how soon could you be down in the valley to do mine....? My beer fridge is fully stocked