First time to post here...Unfortunately I think you guys would consider me from the dark side ( I own a powerstroke), but I am helping a friend by offering to rebuild his 5 spd. I've done handshakers before but not the Getrag. To make matters worse, it is in a box in pieces...I do have a diagram that I got off of the web from highgeartransmission.com, but I would love something more complete regrading rebuild of this trans. if it is out there...Can any of you guys be of help??? Thanks in advance.

 

Send a PM to JLEONAD. He has the rebuild section on PDF or something like that. He emailed it to me, before I got the FSM.

You need to send that box of parts to me, so I can inspect them and remove any bard parts out of it Just kidding. It is not hard to do (I've done it, so it cant be too bad), just have to get your preload EXACT, and dont go over the .008".

Where are you located?

Daniel

 

there are several of us who have teh getrag FSm on PFD file.. Pm me and I will email it to you

 

Thanks guys - I did get a copy of the manual from one of the members. Are there any "gotchas" that I need to watch out for in this rebuild? In a quick view of the manual, it looked fairly straight forward.

 

chrisreyn, i to would like to get a copy of the pdf file on the getrag. considering buying a 91 4x4 donor truck 250k miles five speed pops out of gear since rear end wreck.

 

Farmer... I got it at home on that 'puter, I'll send it this evening..

Greenguy, I have never done a rebuild myself( way out of my abilities!) but I have heard several remarks about how important setting the preload and properly shimming the main shaft is. I gather that you can grenade one by not getting teh shims/preload correct.

 

When taking the synchro retainer off the front of the mainshaft (i believe it is the 3-4 synchros as'y), make sure the retainer assembly all stays together. The detent ***** and springs have a tendency to go "sproing" and disappear into the deepest recesses of your shop. Other than that, it is pretty straightforward.

One thing I will do differently (I just reshimmed the transmission for now- .050" of shims per shaft tells me I need bearings) is that when I do the final set up, I will tilt the case on its nose and take my measurements that way. I was talking to a TDR member, and he set up his mainshaft and got the shim count needed, removed the mainshaft, then set up the countershaft and got the shimming figured out, then did final assembly. He also shimmed it to .002-.004" instead of the 6-8 the book calls for. Someone else with lots of tranny experience liked the "feel" of it better that way. If you must err, err on the side of loose. Pocket bearing can withstand that better than too tight.

DP

 

Greenguy, heres what i read that mentions the shim/preload...originally posted by member" mysteryman"...
mysteryman wrote:

The bearing that fails is the rear main shaft bearing.....This happens due to some of the things I mentioned earlier in this thread....

What you have is a Timkin tapered roller bearing pressed onto the main shaft.....the race is then placed into the rear of the case partially sticking out. Then the tail shaft housing goes over the part of the race that sticks out pressing it down onto the cone....There are shims that go between the race and the tail shaft housing that adjust the bearing clearance..

The failure comes when the clearance is too tight (TOO MANY SHIMS)
This loads the bearing too tight.....When the trans heats up things expand...
This causes the race in the case to lock on the cone and rotate in the case...
This wears out the case and causes the trans to get real hot real fast...Then often times the case will crack between the main shaft and the countershaft bearing bores..... Party over !!!

The bearings in the Getrag are Timken tapered roller bearings just like the front wheel bearings. On front wheel bearings you adjust the clearance with the spindle nut....On a Getrag you stack thin shims.....For new bearings you want a +.006 preload . For used bearings you want .000 clearance.....

Back in the early 90's we were having problems with the remans getrag was sending us...I had about 20 or so that we tore down to find out what had happened...I found that all of them had +.030 to +.045 shim packs.....I thought that I was not calculating it correctly or that the failed units were too bad off to be accurate...
I went to the getrag reman plant way back when to get to the bottom of what the problem was..... I pulled 3 off of the line and tore them down to check the clearance....They all had +.030 to +.045 shim packs in them as well..... Oh sh** ! I called for the production manager ....We discussed my findings...He said that they set them up this way intentionally because they felt .006 was too lose and caused excess gear rattle during testing...OMG !!!

I promptly told him that he was to stick to the spec that WE told them to use and that I was going to write my report to my superiors that Getrag was the cause of the failures and should be back charged for the failures of the remans that Chrysler had had to eat in the previous 3 years!

For those of you that have had one of the Getrags apart . You may have noticed the the rear main shaft bearing race was excessively thick....
The reason for this was that when we were testing the very first Getrags we found that under excessive load that the standard race would split and crack the case...So we reduced the size of the cone and had Timkin make a special thick walled race....It worked and hence the reason for the strange heavy race...
The best thing to do is rebuild the Getrag PROPERLY and put it back in....
There is nothing wrong with the Getrag if you know how to build them !
I have written quite a bit on this subject in the past...Look up the posts...

I know that many think that the NV4500 is a better trans....But we did have the 4500 several years BEFORE the Getrags were used...The 4500 was only used for gas trucks originally....We used the Getrag because it was found to be a better trans during testing.....The 4500 was later used behind the diesels...It had a few small changes made to it before it was used in the diesels but that was it....
The 4500 replaced the Getrag for only one reason...cost !

Rebuilding the Getrag is not hard you just have to pay attention to details...
The Getrag's problems were few but vital... The things that made them fail were as follows...
1) OIL LEAKS
A) drain plug dripped , run out or run low on oil
B) No gaskets on early models , more leaks
C) pilot bushing failures,,, bronze was too soft
D) over loading , trailer too heavy
E) too much hp , turning up the fuel/air
F) overheating ruining the oil
G) wrong type of oil , no 90 weight in the Getrag ! !
H) not knowing how to shift , rattling the gears,, too high a gear at too low a speed

2) Poor assembly
A) setting shim packs too tight , Getrag even did this themselves at times
B) uneven shim packs between main shaft and countershaft causing tail shaft housing not to hit squarely
C) bell housing misalignment

In conclusion, I personally have never had a Getrag fail in any of my personal trucks nor have I ever had to rebuild one twice that I built,, I have seen them go hundreds of thousands of miles in fleet trucks without failures.....

If you still decide to replace it with some thing else I would be glad to buy whats left of your Getrag.. I could use the spare parts ...

Good luck and be sure to replace the pilot bushing. Preferably with a ball bearing... The flywheel will need to be bored out for this...I do my own but the guys at South Bend clutch do them all the time for people.....

As for the pilot bushing....Engineering knew it was not going to work before the first one left the plant...But if you did not haul trailers it would work long enough to get out of warrantee....Engineering wanted to use a ball bearing but . We were shot down due to cost ...
In 94 it was decided to go to a Torrington needle bearing...Great in theory but it just made matters worse....They ate the imputs alive....

As for the worn out ends on the imput shafts...What I do is put them in my cylinder grinder and make them round and back on center..Then I make a steel sleeve on the lathe and press it onto the shaft end.... Then I put them in my cylinder grinder again and finish them to the correct diameter for the ball bearing I am going to use ...The tolerance is .0001 ot centerline . And no your Craftsman engine lathe you got from dad is NOT going to do the job accurately enough !

__________________

 

thanks . even if i don't or do rebuild it i like to know as much as i can before i tear into it. i will try to find a local coach to get me thru the first time. i feel the same way about alll needle bearing and bronze bearings in flywheels.

 

Thanks again for all of the replies. Wow, alot of information...Job sounds fairly easy to complete. Much better than my E40D.....I am thinking of buying a Cummins in a few months anyway.