170K on a Getrag in a '92. What bearings fail?

[Motorhead]

My neighbor has a real nice '92 3/4 ton 4x4 club cab. It has the 5spd Getrag in it. He is ready for a clutch (South bend on order). His trans is a little noisy in low, second and reverse gear. It is bearing noise to me and you can hear it when it is at idle, in neutral, clutch out. He changed the oil on it a few years ago and over filled it by 1qt.
He wants to keep the truck. The shop that is going to do the clutch is also a standard transmission shop.
What is the best approach to this trans? Leave it alone or do preventitive rebuild and or bearing replacement? What usually fails on these trannys?

 

[R C Cola]

transmission Repair

I realize this subject has many opinions so here is mine. When my Getrag went out it was mostly the front bearings (5th went out first and later on down the road would not move. ) Too much money to send out for a rebuild so I did a conversion to the NV4500. Bought the complete kit from Blumenthals in OK city and saved $1500 cold hard.

Unless you are doing the overhaul yourself on the Getrag talk to the guys in OK city, they also sell parts. At about 250k the NV4500 did the same thing so got another rebuilt from OK city only this time I overfilled the NV4500 by one quart. Now have 375K on this transmission and can just barely hear a little bearing noise. Plan to do an oil analysis on transmission soon to see if it shows up. ALL OF THESE MILES ARE TOWING TRAILERS ONE WAY TO DEALERS. This is my work truck. Hope this helps. R C

 

[RedRamAndy]

His trans is a little noisy in low, second and reverse gear. It is bearing noise to me and you can hear it when it is at idle, in neutral, clutch out. He changed the oil on it a few years ago and over filled it by 1qt.

This is very hard to do over the 'net. Getrags by nature are a bit of a noisy beast. My trans was very rattly when I bought my truck. In fact, I got a good price on it since everyone (myself included) thought the trans was shot and needed to be rebuilt. The knocking/rattling at idle almost overpowered the sound of the Cummins idling. I bought a transmission jack and dropped the trans out. (for those of you playing along at home, be careful when pulling the shifter. It's spring-loaded. Go ahead, ask me how I learned... ) After setting the transmission down and getting the clutch apart. i found broke shock springs in the clutch. A new clutch disc eliminated 90 percent of the noise at idle. The trans still grunts and growls in the lowest 3 gears (1,2,R) if I idle along and let the lash go slack and then tight like driving up and down hills. This shouldn't be allowed to happen. The engine spins slowly enough at idle to hammer the trans with each piston stroke somewhat like the beats of an impact wrench. I nudge up the RPM to make it go away. The growling may just be caused by these two things.

I was told to pull a PTO cover and try to check freeplay on the gears (see if there's a lot of gap between them on the shafts, slide them along the shaft) How much??? Mine seemed tight.

I think that if the truck hasn't towed heavily and isn't bombed (tweaked) that the trans might just be OK.

I did drain out the factory ATF from my trans and refill (to the top PTO cover bolt hole) with Redline MTL. This helped quiet the growling a bit too.

There's lots of Getrag tips here if you search.

Good luck!

 

[PToombs]

Usually the bearings fail, unless it's making noise and you keep driving it, then lots of things in it fail.

I have 217k on mine and it just got noisy. It was loud on decel in 5th and in reverse. I took the PTO covers off and found 1/4 inch of end play in the lower shaft. I don't think it had much service before I got it at 189k, but the oil has been changed about 3 times since and I have run it 1 qt overfull for the last 20k or so. I tore it apart and found just the lower shaft bearings bad and the 5th synchro is worn out. Another bad habit I have to break now, resting my hand on the lever! :-laf

I just ordered a bearing with synchros kit and a shim kit for each shaft from Zumbrota Bearing and Gear, $210 plus shipping. Comes with all the shaft bearings, races and all the synchros.



Just do a rebuild, and set the preload in the middle of the spec for new bearings. A fellow member told me that it takes about 5-7 hours to rebuild it and set it up. Hope this helps if you get a quote on rebuilding it.