VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Torque tube leak

I appear to have a minor leak on the aft end of the torque tube. I thought I was leaking fluid from the rear differential, but I am now pretty sure that oil from the transmission may be flowing down the torque tube.

Is it normal for oil to go all the way through the torque tube, or should the aft section be dry? I do know that there is a seal of some sort down inside of the torque tube on the transmission end and perhaps this needs replacement. I recently added oil to the transmission, but perhaps only about 6 ounces or so. It was down, but not much. I figure that it is the leak to the rear that lowered the level.

Rich

Hopefully you simply overfilled it

i would clean all the affected parts from the transmission to the rear end cant fix if you dont know where the fluid is leaking fron . could be the transmission bell seal gaskets , where the torque tube goes in the third member or the rear end gaskets or it may be all of the above . clean it up and let us know . hope this helps

There is a seal in the front end of the torque tube that has been known to fail. That failure allows transmission oil to flow down the torque tube to the differential, allowing for an overfull differential and potential leaks in that area. Check the rear oil level. If oil spills out when you remove the rear plug, the torque tube seal has likely failed. If this is the case, an overfull differential will allow excess oil to the rear axle bearings and could cause leaking of oil onto rear brakes. There is a fix.......an "Oakie Bushing" will do the job. Filling Station, Chevs of the 40s, and others have them.

But before you jump the gun, take pushrods advice, clean everything up and watch for leak areas. Check the rear oil level too.

Good Luck

Ken,

I just changed the fluid in the differential. It was about as close to full as you would want. Fluid did not run out of the fill hole, but when I stuck my finger into the hole, I could feel oil just below the level of the bottom of the hole. What I did notice is that the oil in the differential was darker than what was leaking out. That is why I thought oil might be following the torque tube down to the differential. I did check the oil level in the transmission and it was about 1" below the bottom of the fill hole. I was not aware that oil could flow through the torque tube all the way into the differential. I have about 2,000 miles on my rebuilt transmission and this is the first time that I have added fluid.

I do have a new gasket on the rear cover plate on the differential and this does not appear to be leaking. I suppose the front of the differential could be leaking, but it is hard to tell for sure. What ever the leak is, it is not serious, but I would like to fix it.

I did replace the gaskets on the ball joint when I reinstalled the transmission.

Rich

Sounds as if the leak could be from the knurled collar at the end of the bell that slides on the torque tube. There is a cork gasket there. If it is loose it will leak, you might try tightening the knurled collar, use a wrench to hold the bell and one to turn the collar. The leak at that point is generally easy to spot as there will be gear oil drops on the collar after it has sat for a while.