- Buick Ownership
- 1973 Riviera
Hi all, first time on any forum so be patient with me please. I am in Australia and have a 73 Riviera with 66k miles that i am resto modding. I am having immense problems with the differential. There is so little information and its frustrating. My diff is very odd ball. What i am trying to do is find the correct part numbers including... Eaton True Trac. 3.9 gears to suit. 12 bolt hat to suit with cap tensioners. custom strange axles (bearings and retainers are not listed on strange order sheet). I think but not sure if the 73 has the 12 bolt truck diff as i purchased all above and none fit. The car True Trac is too narrow. Mine is 220mm wide from o.d brg to brg (approximately 9"). My original axles are 31 spline. Diff hat for car is way smaller. Mine measures 275mm (11") centre to centre of across middle bolt holes. My diff hat does not look same as truck hat (see pic attached). Pinion inner bearing id measures 1.865". Axles did NOT have c clips. My diff is an open wheeler, not a factory posi and has a tall ratio i think around 2.7 or 2.9 maybe. One other thing. When we pulled the axles, one had a slight bend, and the axle bearing are different to each other. one is a tapered and one is square. Could the original have been damaged and the whole differential swapped out for some weird diff??? Any how i would really appreciate any input. Thanks, Mark.