Getrag Rebuild

[ellis93]

Alrighty...
Get that trans out and fix that turd.



...this is how I do the rebuild on MY trans and this does not mean that it is the proper procedures. Its my way.
First thing you need to do is find a good pair of safety glasses that fit your face and are clear enough to see thru. You don't need the google kind that make you look like some kind of science geek. Just a decent pair that won't aggravate your nose or ears,the less irritation,the less chance you'll pull them off.
Remember,If you don't wear them, YOUR a BUMB*SS. The flying shrapnel can make you blind or at very least cause you to pay some eye doc to dance a small drill in your eyeball, don't be a DUMB*SS

Tools for teardown and assembly.

Notice the safety glasses!
At very least you'll need:
3/16th pin punch
5/8ths brass drift
A med sized hammer
1/2 socket and ratchet
1/2 wrench
Good sized external/internal snap ring pliers
7/8 cut coal chisel
30mm socket
Brass hammer
5/16 flat screw driver
Bearing spliter(very nice to have,can get by without)
Die grander with 3"cutting wheel
2or3 jaw puller

Tools not pictured are pry bars and two heel bars and a 6x6 wood block


Now I tear in,starting with the shift covers 8 bolts

With the trans in neutral the cover should lift up

Next the input retainer and bolts


Now the yoke,tail housing and its bolts. Don't forget to pull the speedometer gear and housing.

Under there should be shims for the counter shaft and main/output shaft. Also,if your working on a 2wd, there is two spacers and a speedometer drive gear.



After all that is out of my way I pop the races out of the case with my trusty craftsman screw driver. I take the blade and wedge it between the outer race and the bearing cage. Working all the way around,walking it out

Input



Output/main shaft and rear counter



After they're out of the way,you can wiggle the input forward and pull the mainshaft backwards to get some space between the two. You'll need this gap to get the mainshaft to come up and out of the case

If you look at the raised end of the mainshaft there is a slider there. DON'T let that move ANY! If it moves there are shift dogs/keys that have balls and springs in them. If the slider moves the balls and springs will fly like bullets,this is one of the times when the glasses are needed,remember don't be a dumb*ss LOL

Now press down on the rear of the shaft and lift up the front and it should come right out


After its out of the way you can pull out the input shaft


Now we have a good look at the counter gear and reverse idler.

[ellis93]

Now,looking at the rear of the trans,you'll see the counter shaft bearing and a snap ring

Pull that snap ring off and be careful with it,it'll bend easy and they won't come in the bearing/syncro kit

Take a drift pin,brass is my choice,and carefully drive it forward. The shaft moves inside of the counter/cluster gear.

Reason you drive it forward is to pop the sealing cap out of the front bearing journal to revile 2 other snap rings. One that holds the front race in.

Now once the caps out of the way remove the big snap ring.

Now we can go back to the other end a finish bumping that shaft out



I now want to remove the reverse idler and its parts. There's a bolt on the outside of the case,it comes out first so I can angle the shaft to drive the roll pins out easier.

Now both pins


I remove the counter/cluster

Then push out the idler gear shaft

What comes out


Now that the case is empty I turn all my attention to the mainshaft. I start by cutting the pocket bearing cage and race. After I've got rid of the cage and rollers I slice the race carefully,not cutting into the shaft or 3/4 syncro hub. You don't need to cut it more than 3/4 way,you'll take that chisel and hammer to split it the rest of the way. After its split then it'll slide off with a little persuasion with a pry bar or screw driver.
How I make it happen,yeaaah


Now remove the 3/4 hub assembly,remember keys,springs and balls,PITA to get back together,IF you find ALL the pieces. Best to just not let it move :p

3rd gear,the bearing and old syncro

Now on the shaft is a snap ring and a retainer. They how the 2nd gear and 1/2 syncro assembly in place on the shaft. Remove the snap ring

Here's the ring

Here is how I get it off and how the 6x6 comes into play

Pick the shaft up and let it fall,nose down,agains the block. This is what should come off after a few good hard drops


Now we'll move to the other end of our shaft and cut on the bearing

Cut the cage,remove the bearings and cage with the screw driver or pry bar

Now slice the race and split it with the chisel

Now the 5th gear falls off

Now another snap ring that holds the 5th/reverse syncro hub on.

Mine was stuck pretty good so I had to walk it off with to heel bars

Remember PITA if it comes apart.
With that removed you'll get this off

Then another snap ring and retainer

Remove the snap ring and pull the block back to you but before we pound on it with the shaft,screw the yoke nut back on the shaft, you don't want to booger up that

Bring the pain

And its off

One tore apart getrag


Reassembly

Ok I don't clean everything at once. I know where everything goes by how a place it on the floor/cardboard,so I'd probably be in a pickle if I jumbled it up cleaning it all at once

These four pieces are the first to be scrubbed clean of dirt,oil and shavings.

I get the mainshaft clean and stood on the front end,pinched in my bearing spliter on top of a block

Ok now I lube and install the 1st gear needle bearings

Before you slide the 1st gear on you'll need to remove the old syncro,I pry it off EVENLY and put on the new. This gear there are roll pins that have they're holes drilled all the way thru. Bump them out and back in thru the new syncro first.


Make double sure that the roll pins are flush with the inside of the syncro,otherwise you'll not have full engagement of the collector ring

Slide the gear on and find its retainer and snap ring. It may not matter but I always make sure to keep the old surfaces against the same places. This pic shows where the needles and bearings rode against the retainer.

And I drive it down evenly and with small taps,all the way around till it seats.

after you get the retainer down,now the snap ring. I bump around it with my pin punch to make sure its seated all the way in its groove.

After this there's another needle bearing and the reverse gear. The next thing will be the reverse's syncro and the syncro assembly. You'll need to pay attention to the hub because there is a thick side and it goes down into the reverse gear.

Now the 5th syncro

And the 5th gear and its two piece bearing



Now for the rear bearing,usually I use a press to mash them on but since most folks don't have one in their back pocket I did this to show you can do it without.
I drove in on using my brass drift and even,medium forced blows,around the inner bearing race. I was careful of the bearing cage, to avoid any contact with it, it can withstand some but its better to stay away.

After that, the rear portion of the shaft is finished and its time to flip it over and assemble the rest of it.
Slide on the 1/2 slider assembly

Replace the 1st gear syncro,not as easy as the 2nd gear. Its roll pin holes are blind,meaning they're not all the way thru the gear. You'll have to remove the old syncro with a screw driver or chisel and drive the new one back on REALLY carefully. You'll have to keep close to the holes in the syncro when installing it to keep the syncro from warping or binding. That could cause nasty shifting characteristics.


Now you can slide that gear and its needle bearing on and its retainer time again

Make sure the snap ring is seated

And the 3rd gear and needle

Now the 3/4 syncros and assembly

I drive the pocket bearing on the same way as I did the rear mainshaft bearing

Ok that's one complete mainshaft

[ellis93]

Now that the mainshaft is together I turn toward the case and reverse idler.
Take the idler and slide the needle bearings inside along w/ their spacer, should be bearing-spacer-bearing

Now I take it and one of the thrust washers ,there are oil grooves and a square slot on them,square slot points away from the gear,and put it in the case with the idler shaft started in its bore. Notice the hub on the gear goes to the front of trans

As I push on the shaft,I make sure one of my fingers are holding the bearings in. Once the shaft is flush with the outside of the gear,I slide the other thrust washer down next to the gear and push the shaft the rest of the way in. The rear roll pin will need to be driven in before you go any farther,once the front roll pin is in you can't get at it because the gear sticks out over the hole. When its all in I take a small screw driver and insert it in the front roll pin hole to allow me to turn the shaft so I can start its bolt

Once the bolt is started,drive in the last roll pin and it should look like this.

That pic was taken directly over the gear,notice the rear pin can't be seen

nows the time to drop in the counter/cluster gear.

Now its shaft with a new bearing drove on its front.
Don't worry it won't go but one way. Make sure the bearing points outward.

After the shafts in, install the race and its snap ring


I turn the case on end an install the other bearing. I also have a small piece of brass backing the other side of the shaft,this keeps the force from driving the other bearing on off of the race snap ring.

After I get done driving on the bearing,I set the case back down and install the input and its bearing. There is some syncro teeth on it that have been machined down to allow it to move above and forward of its matting counter gear.

Once its in there,its time for the mainshaft assembly,careful of that 3/4 syncro assembly.

I also install the input race and retainer. Also the cap for the front counter shaft bearing,I put a good layer of Ultra Grey silicone on the outside of it as well. I don't like oil leaks and definitely not on my trans.

After all that I pick the entire trans assembly up and set it input down thru a metal milk crate to do my bearing preload

My preload measurement is done the exact way Ahale2772 does them, so I asked him if I could borrow his write up on his 4x4

here is how I did the preload... both shafts to .005

first, press all the new bearings on the main and counter shaft. make sure the bearings are FULLY pressed on to the shafts. install the input bearing retainer, front counter shaft retaining snap ring and put the races on the rear bearings. set the trans on its nose so that both shafts are vertical.

note: I did all of this with the bearings dry, so that no oil would effect my measurements.
Next, you need to measure the protrusion of the main and countershaft races. used a depth micrometer and check many places on the race to get an accurate reading. I found that the countershaft race was set in the case more and would not rock. But the main shaft race rocked 2 thousands of an inch. therefor I got the average of all of the measurements.

the mainshaft race...

the countershaft race...

it is SUPER important to get these numbers right. any doubt, check it again.

next, you will need to measure the depth of the machined counterbores in the tail housing casting. these numbers should be very accurate around the curcumferance of the bore.
main shaft bore..

counter shaft bore...

my measurements...

first the main shaft...
the race protruded from the case .233
the counterbore for the mainshaft was .255
subtract .233 from .255 and you get .022
REMEMBER this is the amout of shims you would need for ZERO preload.
the preload I used was .005, hence to get the correct prelaod you need to add .005 to .022 and I needed .027 inches worth of shims.

next, the counter shaft.
I found that the race protruded from the case.038
the counterbore on the tailhousing was .103
hence I would need .061 inches worth of shims for ZERO preload
add .005 to .061 and .066 is my final shim requirement for the counter shaft.

next, measure your shims.


I bought a main and countershaft shims from ZBAG, they were about 7bucks each and well worth it. ALLTHOUGH, they didnt have any shims for the countershaft over .010.

shims for the main shaft. .020 +.007
countershaft .020 X3, .006

your job should be complete, have someone check your math and the n your ready for assembly.

just to check... I put the tail housing on for a mock up run and used a feeler guage to check how much the housing was wsitting off of the case.

.004 was loose, .006 was too tight... .005 fit just right

tighten her up!

Ok only thing different from that to a 2wd is our output shaft and tail housing.
Also our speedometer drive and spacers

Also don't over do it on the silicone on the tail housing and use the ultra grey stuff. That mess is bad news once it dries. Seems like the other stuff,blue or red, like to be a little porous and let oil out. The ultra black is pretty good but I favor the grey for the simple fact that most auto manufactures use it for most of their sealing requirements now days.
One final thing make sure you dab a little between the nut and yoke,ever notice the yoke being damp with oil,it'll stop that .

And loctite the nut treads. I've had mine back off a time or two.

Last thing to do is to drop you shift cover back on and tighten it up.
Finished. Good luck with yours.

[ahale2772]

awesome!!! SHTICKY

[Mark Nixon]

Ellis, hope you do as I suggested and open up the slot(s) in the input a bit.
Also, it may be overkill, but if you PLAN to tow heavy, have the case magna-fluxed, it's worth it.
I'd also like to see a pic of how the input is trashed on the backside, just for reference of the biggest troublemaker for the Getrag.
A word of warning (advise), don't lose, or screw up the yoke nut.
They are not available new (that I have found) and in a box of random parts they usually end up missing, which also means they are hard to come by used.
To this point I have yet to find anything even close to this nut.

Mark.

[ellis93]

Ellis, hope you do as I suggested and open up the slot(s) in the input a bit.
Also, it may be overkill, but if you PLAN to tow heavy, have the case magna-fluxed, it's worth it.
.

I've been thinking on it some and I'm figuring on doing it. If there is only one slot in the new one,there WILL be two when its install in the trans.

[ellis93]

New stuff added,more to come
My freaking thumbs hurt BAD from typing this stuff out on my blackberry

[PToombs]

Clean your bloody hands get on the real computer! Good writeup Mr. Ellis.
You should add that there is a flat side on the input shaft gear that should go "down" for better movement forward when disassembling. Also, be careful when driving on the countershaft shaft. If you get near the edge, you can break off the lip of the snap ring groove going in or out with it.

[ellis93]

Clean your bloody hands get on the real computer! Good writeup Mr. Ellis.
You should add that there is a flat side on the input shaft gear that should go "down" for better movement forward when disassembling. Also, be careful when driving on the countershaft shaft. If you get near the edge, you can break off the lip of the snap ring groove going in or out with it.

Yeah I know I'm missing small bits I'm planing on refining it some
The brass drift I use is "dead soft" and it was about 2' long at one time so I figure it was safe to use on that. If some one was to use something harder they really should stay away from the edge. There is however a divit machined into the end of the shaft so it could be used as a center for driving it out. Problem I run into is that your out to mushroom the end of the shaft using hard material to drive with and you'll usually have chips flying into parts of you body that can't withstand steel
I'm gonna try and fill in some more in the next couple of days of how to pull the syncros off the 1st and 2nd gear faces and some of the reassemble of the mainshaft. I may ask alex to edit his post on here with his preload measurements and pics off of his trans tread, would ya alex huh huh huh please.

[ahale2772]

yeah sure... Ive got no problem with that, what do u want to do? just copy and paste it? let me know

EDIT, I PM'd you that text, I though sending it through PM would make the pictures not appear, but they still do, if that is an issue on your crackberry let me know

probably a good eyed-deer to do a write up on your trans too though, I don't know if a 2wd trans is exactly the same??? (can someone clarify that?)

im sure the preloads are the same, Just don't know if the size or position of either race is different?

[ahale2772]

better to have it all in one place anyways

[ellis93]

Thanks a bunch alex!
I'll copy and paste as a quote.

Reckon anyone wants to see the shift cover torn apart,even with most of its part not available? You can buy the forks but not much else,plus its almost cost effective for me to buy the whole cover

[ellis93]

New section added to second post

[Mark Nixon]

Just a note.

A piece of thinwall conduit, or even a section of mild steel plumbing pipe, that fits just inside the outer diameter of the inner race will allow a person to hammer the bearing onto shafts evenly.
This is given that a person doesn't have a taller press to push them on with instead.

Mark.

[Farmboy]

Definatly a good post.. 3rd gear synrco is going on my rag.. will be looking this post up at that point...

Sticky!!