Story of a "rebuilt" QuadraTrac

August 2006

As told by Flint:
We got tired of trying to find rebuildable parts for QuadraTrac differentials. I had been drooling over NOS QTs found on eBay in the spring of 2006. Shortly after that I found a tranny shop selling off old inventory on eBay which included a rebuilt QuadraTrac without low range. The cost was $450 shipped. I spoke to the owner a few times before buying the QT from him. In June, I installed this QT in Phoebe and we took it for a test drive. We got just over 3 miles when there was a clunk sound and it felt like the front drive shaft was not under power. When I put it in Edrive, there was power to the front. We drove it home and I studied it for a while, not finding anything obvious. We were up against deadlines to be ready for Ouray in a couple weeks. It seemed to be working fine in Edrive so I called it good enough for the Invasion.

On the first day on the trail over Stoney Pass, Krista started having trouble getting power to the front end on a steep portion of the trail. On the second day we were headed up to California Gulch when she found out the front was no longer pulling even in Edrive. She turned Phoebe around and went back to the KOA. We left her parked the rest of the week in Ouray. She drove home under her own power until about a mile and a half from home when the QuadraTrac seemed to get stuck in Nuetral. I put the low range shifter in Nuetral and we towed her home the rest of the way. What actually happened was the front output shaft started coming out of the QT and the DC ujoint was starting to rub against the T400 housing by the oil pan. When I removed the front drive shaft, the output shaft came right out in my hand along with the bearing and outer C clip. All this in about 300 miles.

Upon inspection, this is what I found:

The differential was totally ruined by this failure. The front brake cone started to waller out the cone surface in the differential hub and trashed the front brake cone. The QuadraTrac was a loss.

ground cone surfaces:

spider side of brake cones - left is rear output - right is front output:

cone washer side of brake cones - left is rear output - right is front output:

The short story is the seller died in a car crash that summer. It took months to get someone to respond. The family of the man who sold me the QuadraTrac decided they did not owe me a thing for the damages. We were screwed.