There has been sludge accruing on the casing around the pumpkin, and I'm not sure what could cause this. A new gasket has been installed with new fluid done by the best transmission shop in town, so this leads me to thinking the rear end has some part failing causing the appearance of sludge. Anybody have any insight into this phenomenon?



I havent wiped down all of the rear end. If no good conclusions can be made from these pictures, i will go and wipe it all down so you can see better.

 

Looks like the typical leak around the tubes where they're just pushed into the machined holes in the pumpkin without any manner way shape form or fashion of sealing not even an O-ring, and temporarily partially retained by the 2 plug welds on each one, which are usually cracked.

Nothing I see looks even vaguely like a mystery. Very ordinary really.

You can go to the quarter car wash with acoupla cans of engine degreaser, and soak all that crap real good for a half-hour or so with several applications, then blast the crap out of it; to get it largely clean. Likely to be easier and more effective than wiping. Although, after that, a rag moistened with diesel fuel (aka engine degreaser) could be used to clean up what's left after blasting.

 

And then the proper steps after cleaning it up nicely would be a diagnosis of the leak? Or are these rear ends known to leak and it's pretty normal/harmless?

 

Yeah they all always leak, sooner or later. Just LOOK AT how it's made... they took a casting, machined 2 holes in it, jammed 2 pieces of tubing in it, and "retained" the tubing with those plug welds. It's amazing they leak as little as they do and go as long as they do before they get really bad.

The welds always crack after acoupla decades, and then the tubes are about always loose in the casting, sometimes so loose you can turn em in the casting by hand, or bend em back and forth. I've had more than one car that made weird little clicking or other sorts of noises when, say, shifting from forward to reverse and back again while sitting still, just from the tubes rotating a bit in the housing. Sometimes you can actually see em doing it. It's PARTICULARLY a problem with leaf-spring rears (2nd gen F body for example) because then, those 4 stupid little welds are THE ONLY thing keeping the pumpkin from rotating itself on the tubes which are fixed in place by the springs. Full drive shaft torque is applied to those little welds at all times. Our cars, with the torque arm that holds the pumpkin in place, aren't as hard on the welds as those others.

Long-term solution is, weld them in properly, all the way around, making POSITIVELY SURE that they are ABSOLUTELY STRAIGHT in the housing; and fill in the little weenie plug welds so they don't leak. All of which is more easily said than done; welding to cast iron is almost impossible unless you get it at least brown hot first. If the tubes aren't straight, the rear tires won't be right... they'll either have toe or camber, or both, which makes it impossible to give the car a proper alignment. It'll "crab" or wear tire edges funny or otherwise misbehave.