Mpgp1999

Transmission catastrophic failure

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Right before the Wisconsin meet my I changed the oil in the transmission and found lots of large metal bits along with very shiny oil. When driving. Can feel the transmission moving in the case. I bought another one and put it in. (Maybe incorrectly). The countershaft has more than 1/4 inch of play. Some of the gears got chewed up. What does the countershaft ride on. The transmission is from 1925. How can I repair it. In my (new) transmission after about 1000 miles the oil is shiny with tiny metallic parts. I sent it to a lab and they said it was mostly lead. What can I do for repair the broken transmission and how can I prevent the countershaft from breaking. Should the universal joint be packed in grease? 

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My plan is to repair what was damaged at my schools machine shop. Are there any better diagrams of the transmission than whats in the owners manual. Does anyone have any specs for when I machine parts. For example, a bling bushing needs to have .458 ID and a .635 OD.

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This is the replacement countershaft bearing.  The original roller bearings were groves for oil flow. Should I try to find ones with the groove. 

 

Picture courtesy of Myers Early Dodge 

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Ok, I can't say for sure about that exact transmission, and I hope you get better advice, but here are some thoughts If anything I say contradicts the manual, listen to the manual....

 

Did this fail catastrophically and go "BANG!" or just present itself with a bunch of metal in the oil? Is that case bent? Probably not but it sure looks strange in the picture. Maybe its perspective distortion in the picture.

 

The u-joint is almost certainly lubricated with oil. Greased u-joints generally are full of needle bearings. That u-joint in the picture appears to be bushed. Chevy used joints like that, and ran them in oil. They have to have oil, in fact it is required that you fill the u-joint separately on a Chevy because the oil from the transmission will not flow out fast enough to prevent catastrophic damage in the first few blocks! If Dodge does not specifically say to grease it, assume it runs in oil (it looks like it does in the diagram you posted), and make sure it is wet and will stay oiled before you drive.

 

As for the transmission, just disassemble and clean everything! get it spotless. You have access to a machine shop? Thats great! Change the bearings and/or bushings and check that the shafts run parallel. Inspect everything closely. You can probably tell where all the metal came from. It's missing from something.

 

Those pointy bits on the gears should be pointy. It is pretty normal for them to be all beat up. Thats ok, but worn flattened isn't. The one in your picture looks ok. The shape should be more or less like the roof of a house. Also look at the flat sides of the teeth. The teeth should have the same thickness where they intersect the pointy bits as they do at the back of the gear. If they wear tapered, the transmission will want to pop out of gear.

 

Other than that, replace all loose bushings or bearings. Pay attention to how things get oil, like that u joint. Oil probably gets there by oozing through the rear bearing, but I am not sure.

 

There is going to be some metal in the oil due to clashing gears. Nobody hits it perfect every single time. Someone else will have to advise you on what kind of oil to use. Protecting the teeth on sliding gears as they clash is a completely different problem than oil for the synchromesh on slightly newer cars. Maybe 600W would be appropriate. I would be tempted to try Redline Heavy Shockproof in this, but I am not going to recommend it because I haven't done it. Probably something thick. Change it once in a while.

 

Edited by Bloo (see edit history)

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I think the grooves in the bearing may have been more to do with the manufacturing technique than for oil distribution.  I doubt that you will find them with the grooves.

 

i had the same issue with my box, it worked but was noisy.  Turned out the cages had broken for all three roller bearings.  One thing to check before you re -assemble is that the shafts that the bearings run on are in good condition.  Mine had quite a lot of wear on the lay shaft - if I’d put it back together I think it would have destroyed the new bearings in no time.  I think if the wear is only slight, you can turn the lay shaft 180 degrees as they tend to wear more on the loaded top surface.

 

cheers,

Richard 

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