Getrag back together

[BJMarshall]

I finally got my truck back together and thought I would post my experience. Tore it down to put a new clutch in it and decided to do a little freshening to the trans while I had it out. I bought parts from South Bend, Man-trans, and Quad 4x4. Even though I didn't spend much with any of them, their service was good. Man-trans was a little slow on shipping, and I never did get everything I wanted. I had ordered an assortement of shims for the Getrag and all I ever got as far as shims go were the ones for the mainshaft. Never got any for the countershaft, and that's where I really needed them. I wound up making shims for the countershaft.

I didn't tear the transmission down all the way. The bearings on the ends of the shafts looked fine, it was just a little loose. The countershaft needed a good bit of shimming. The mainshaft only needed a little, but it was very loose because the input bearing retainer bolts were loose. I was probably near a major problem. I wish I had torn it the rest of the way down and checked the pocket bearing. The transmission is much quieter now, but I have a little noise in 4th only.

I had a local place build the clutch for me. All I told them was I wanted it to stand up to the extra power and not slip. They gave me a button clutch. I wouldn't recommend it, but it definitely doesn't slip. I will probably go ahead and spend the money for a South Bend as soon as I am able.

Sorry for the book.

 

[1stgen4evr]

touch up the getrag

Congrats, that makes you a participating member of the Getrag preservation society. Noise in fourth, just might be a noise that is telegraphing into the transmission from a ujoint or rear end. In fourth, the torque is straight through and shouldn't be loading a bearing much. I would venture to speculate that you didn't encounter any boogers in there.



Do remember that you can exceed the capacity of the Getrag with 4x4 and a little bombing. Pet it just a tad and it will be with you for the long run.



And yep, you shoulda' pulled the input and looked at the pocket brg.



James



Next step will be sustaining member. That requires that you help a novice do his.

 

[ARhine]

Somebody can help me



I am gonna get my rear u-joint replaced first though. Mine makes a buzzing in the shifter in 4th and 5th on mornings when it is below 25 or so degrees. I have 5qts of mobil1 in it.



Also when putting the power to it there is quite a bit of noise in the floorboards of vibes between 2000 and 2200 rpm or so.

 

[BHiggins]

Getrag

I'm on my second first gen. truck, both with Getrags, and both made a little noise in fourth gear. My first one, a 1990 went 304,000 miles without any work to the transmission. My "new'" truck is a 1992 which I bought with 70,000 original miles and two weeks later the Getrag went south. I think driving style has alot to do with longevity of the Getrags, in other words don't lug fifth gear and you should get ALOT of miles out of it.

 

[bgilbert]

Can someone explain to me the 'BUTTON CLUTCH'? I heard of them used, but not sure what it means. Also hear they make the clutch pedal tough to push? I'm needing a clutch pretty bad, and need one that won't slip under 450hp, 1000+torque at the wheels.

 

[1stgen4evr]

button clutch

Industrial clutch design that is comon on loader/backhoes and such. Rather than a continuous ring of friction material, the clutch plate will have four or six 'buttons' of bronze on each side. The buttons are about 3 inches in diameter, fastened through the center with a swaged attachment. If the pressure plate isn't made for the button clutch, it will slip as the correct pressure plate has more springs to grip the clutch. Yes, it is harder to depress the pedal. It is a very agressive clutch. It doesn't function like a 'dry torque converter' as the stock clutch does. It is pretty much a zero or one connection.



James

 

[MMiller]

Button clutches are notoriously aggressive on engagement, and hard on flywheels. Yes they hold torque and grip quite well, but can be very difficult to live with. I try and recommend my friends not use them. Most that try them cause of price, or performance end up regretting it in the end. Holding the torque means nothing if you jerk the heck out of the truck on engagement.



BJ-glad to hear your getrag project went well. Do not apologize for the "book". Its easier to get it all out first then try and re-explain it several times. I have been happy with the performance of my getrag, and hope that it keeps running well.



Michael

 

[dpuckett]

Getrag longevity

Not lugging applies to ALL gears, esp corners in 3rd or 4th. Any time you stomp on the pedal at lower RPMs, it strains the internals. Mine starts to really complain in 4th gear if I get into it below 35mph (I will soon know how many RPMs that really is Oo. ) and make, oh, say 20-30 psi by 40mph. If Greenleaf redoes/ upgrades my pump, I may see an Eaton 7 speed in it this summer. (g/f's boss runs a repair shop, and has access to all kinds of machine shops and guys who are into this kinda thing He would be embarrased by a 14yr old truck with 300K spanking his chipped 7. 3, though). ALso, as 1stGen4ever said, you need to monitor the fluid level. If you tow, or puah a lot of power through it, I'd recommend a heavier viscocity oil, like a 5w40 or 15w50. Something a little heavier than the 5w30 that is stock. Mine shifts just fine in the relative cold (teens and 20s) just as easily as when it is 90deg (not too far away).



Daniel

 

[BJMarshall]

As James and Michael said, the button clutch is very aggressive. I imagine I will be changing it out sometime in the near future. I think I will go ahead and tear the transmission all the way down and possibly put all new bearings in it. Not a lot of expense if you do it yourself, and it is much cheaper than replacing other parts. I wish I would've done it while I had it out.

The button clutch holds very well. The aggressive behavior is not nearly as noticeable when the truck is loaded heavy. Running empty though it is basically on or off with no in-between. I've got a 6 button in mine with bronze pads. One other difference is there are no dampening springs on the hub. I have heard this will contribute to wear on the input shaft, but I haven't experienced it firsthand.

To each his own as far as the oil is concerned. I have run Mobil 1 15w50 for quite some time now, and it seems to make it a little quiter, but it is a little bit harder to shift when cold. The main thing is keep it full of something.

 

[MMiller]

BJM

Does your 91 have 6" blocks in the rear? Reason I ask is a chattering/aggressive clutch is much more noticable with bad axel wrap. Mine will wrap and wheelhop bad if I am not smooth enough, or if I'm trying to get a heavy load started with poor traction. That is with a stock clutch, can't imagine a button in the mix!



Michael

 

[BJMarshall]

Mine has the 4" blocks. I would imagine it would be more exaggerated with if it had the taller blocks.