Long story- short version- Axle seals leaking- knowing that my car didn't come factory with the 12 Bolt (I still have the original 10 bolt that came with the car)- So I go to the parts store armed with limited knowledge- order seals for a Chevelle (they didn't list any for the buick)..and lo and behold- they fit and worked perfectly. I have a 3.31 ratio (43 teeth/13 on the pinion) Limited slip. I can break either wheel loose (very difficult) with the other on the ground, and leaves 2 very nice tiremarks whenever I chose. Also, the backing plates for the brakes didn't have the adjuster covers knocked out (so I removed them and put in the rubber plugs) What do you guys think this rearend came out of? It has 1.4 " diameter axles (at the bearing end) but all applications I've seen for this rearend (Nova/Camaro/Nomad) are all leaf spring cars, and this was definitely not a leaf axle- Never owned or looked at a Chevelle- is it possible it came out of a Chevelle- I just don't know what I have in there- I used 85w LSD oil- anybody have a better recommendation?? thanks for any and all help- Bryan
It is a Chevy 12 bolt 1965 -1972 a-body rear. 1.40 is the axle bearing surface and it is a c-clip type rear. It will have 12 bolts on the ring gear and cover. The 1965-1967- rears are 54 1/4 backing plate to backing plate and the 1968 -1972 are an inch wider at 55 1/4. Should be a four link set-up 2 upper control arms off the center pumpkin and 2 lower driver and passenger side control arms. The backing plates need not have the adjuster holes it is all done automatically everytime you reverse the car. They self adjust as long as the system is in goo working order. If you give me the axle tube stamping on the passenger front of the axle tube between the spring perch and the cast center section I will run it and tell you. You also have a casting number in the center section webbing along with a date code. clean it up and look for them. measure the width from backing plate to backing palte that will help too. best thing though is that stamping on the axle tube. Jim
You, my friend, are a pure genius. I will find the codes and get back to you. do you have any idea (i'm sure you do) about what type of oil to run in this rear end? I feel the posi when i turn sharply either way from a stop under part power- I wonder if i am using the right lube- and I don't want to drive it if i'm going to mess something up- I am assuming a 3.31 is a decent ratio for the big block I'll be putting back in it- I drive 12 miles one way each day on the freeway and never go over 70- Thanks for all the info- and I'll measure it as well, because the 26x12's I have on the rear (on 15 x 10's with a 5 inch offset) still have plenty of room between the tire and outer ww trim- almost an inch and a 1/4.
