We just put a different rear axle under my 1 ton panel. I talked with Phillip at Patricks. He suggested we look for a late '80's early '90's F350 passenger van rear end with a 3:55 and thought we had one from the local wrecker, it was the correct length and looked right. It was supposed to swap out easily with a few things such as new purchs etc. Our first clue that we didn't have what we thought was when the Ford lug nuts didn't fit, but GM did. Then, the drive line had to be shortened so we had the U joint changed at the same time, wrong U joint, too small, we went back to the old U joint. Then what cinched it was the brake line, it needed to be changed due to damage, quess what, another GM product fit. Now comes what we probably should have done first. We pulled the cover, counted the gears and there were numbers on the ring gear. We were told it was a rear end from an '89 Ford 3/4 ton passenger van and that it was a 3:73, it turns out that it is a GM product with a 4:11 gear ratio. Everything is connected and the brakes are bled but it will be a while before we get it out on a road test. The good part is that it was an easy swap and would have been easier if we had known what we were working with. The brake lines connected easily as did the emergency brake, it is a single axle bearing instead of 2 so it will be easier to work on and it can wear hub caps on the rear wheels. Now I'm trying to figure out what rear end it actually is and if the gears can be changed. We already put in an S10 T5 tranny that works great and hoping the 4:11 gear ratio will work well.
We can't find numbers on the axle. The numbers on the ring gear are: T or 1 GM 2601(598)21041(5)91 and it is a slip diff. If anyone knows how I can figure out what this axle is, it would be greatly appreciated. It needs a vent valve, right now there is a hose attached to the vent. Obviously it will be easier to get parts if we know what we have.
