Greetings folks, my first time on here.
Hope someone can help me out here, Iím just about pulling whats left of my hair out.
I just got my 59 El Camino finished; (350/th350, 10 bolt posi rearend from 72 chevelle)
After you drive it about 4 miles, a loud CLUNK starts coming from the rearend. Its not a regular clunk but it is quite frequent. Most noticeable at low speeds going dead straight. Severe enough to jar the vehicle.
The rearend has been apart, and all seems OK. I did not take the pinion assembly out, but it spins freely and there is no play. There is a small amount of gear backlash, but not excessive, and there is a little backlash in the spider gears. The posi clutches are new. The crosspin fits snugly. Wheel bearings seem fine.
The odd thing is that with the rearend up on jackstands and running in drive, it does not happen, even with the parking brake partially engaged to provide some load.
When it first started to happen , I assumed it was the driveshaft center bearing, but It was fine. (I replaced it anyway) all the universals are fine and no amount of experimenting with shimming pinion angles etc makes any difference.