James_Douglas Posted October 3, 2021 Report Share Posted October 3, 2021 I really do not want to have to replace the rear end in the big Desoto with something else. But, the ring and pinion is becoming a PITA. The DeSoto Suburbans share the large chassis of the Big Chrysler 8. If it only had the eight! The issue is that I have called and called everyone that has parts and nobody has a set of NOS ring and pinion gears. My 4.11 set is way to pitted to reuse. I have a NOS set of 4.55 gears. But this may be way too much. Keep in mind that with the 3.91 gears in the car right now it is straining to make it up a big hill or mountain. I almost have to drop from their gear (on-OD) to Second. For those of you that know the SF Bay Area, on the way home to SF I am in 3rd non-OD at full throttle to make it up Waldo Grade to the bridge. Attached is an screen shot of an excel spreadsheet of my trans and the the gears 3.91, 4.11 and 4.55. Until I pull the unit I have no idea as to what the shape of the 3.91 is, but it is howling like a sick dog. It could be just a bad bearing, but I doubt it. I would like peoples thoughts after looking at my spreadsheet as to QUALITY of driving with the NOS 4.55 gears in a car as big and heavy as the Suburban with the overdrive. I added a line for second gear overdrive for city driving at 35. I am thinking it may be a little much as the OD governor does not kick in now until about 25 MPH. Thanks, James Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.