Hey fellas, little help needed. I have a 12 bolt cover (perfectly round) 12 bolt ring gear under a 72 Suncoupe with an open diff. I am trying to ID the gear set, and only numbers on the ring gear that are visible with it installed are 16441 GM A11 98 Pretty sure on all the digits except "A" could be a "4" but pretty sure it's an A. I am pretty sure this an aftermarket set as it is in exceptional condition for it's age. Also rear end had to come from a donor car but I can not find any numbers of tubes. Diff is out of car and I can look harder if anyone knows where they could be, a lot of surface rust and I think if I sand I would sand of numbers too. I am wanting to go to a posi so if any one has a lead on one that would fit this set up let me know. I appreciate the help guys. Thanks, Rob
Have to make a correction or two, got into the garage tore down diff and now I have info. Ring gear has 10 bolts not 12 and the first digits are 16a41 which should make this a 2.56 set I believe and 28 spline axles so this opens up a lot more choices. Still need a posi and now a lower gear. Any ideas? Recommendations?
Stock rear in a 72 Skylark/GS should be an 8.5 10 bolt, or a 12 bolt if the car was built in Canada. Sounds like you have an 8.5, but with a 40 year old car, the rear might have been changed. Post some pictures. There is great parts availability for the 8.5.
If the cover is perfectly round 12 bolt and the ring gear has 10 bolts you have a Oldsmobile 12 bolt rear diff. Jim 1967-1970 will be the years it was used.
So monzaz should I build it or ship it. Local guy that does an awesome job says he can build it as a 3.42 posi stock axles for $1800.00. Seems like that is about right but I do have a buick 8.5 I believe out of a 71 lark that I could throw under it. What would you do? Not building a track car, just a ground pounder street car (550hp 455) Track maybe three days per year. Any advise appreciated in advance.:beers2:
theres not alot of support for the Olds 12 bolt, it gets expensive..id run a 8.5 you can buy parts at autozone....really reasonable to build
If you have all the parts it will not be a bad build. Just remember the clutches are not =being supported nor the spider gears for the original units. Seems as if you could spend less on the 8.5...and the 8.5 will be stronger too. Did you say you had to ship it? What do you mean? Jim
Ship it meaning give up on it. A local guy who does good work says $1800 to build it with 3.42 or 3.90 Richmond gears (states up front may whine). Good deal? What would a guy expect to pay for a similar build on an 8.5? Thanks for the help, Rob.
I will build it and it wont whine. I do not understand that disclaimer... WHY pay him to do it then? Just do it yourself if it is going to whine... I will build a 10 bolt 8.5 gear choice of 3.08 3.42 or 3.73 for 1250.00 out right NO core needed. Jim Brakes are 195.00 ontop of that...BUT all new and include brake lines and rubber chassis brake hose too.
Might have to go that route, plan to have it powder coated so how would that work into the plan if I have you build me set up. What's freight to 80439 (business with loading dock)? This might be the best way for me to go. Let's see if we can make this work. Thanks, Rob
To me Powder coating is way over rated. Most these muscle cars never see rain snow mud etc. So the need for that seems over kill. besides if it does get nick you have a large dent in the powder coating that will need to be filled and I almost guarantee when you install it that WILL HAPPEN My whole car is regular prime and chassis painted and it never rusts. I will need to see what that will cost for the coating. Jim Shipping to commercial 80439 is 176.26 MAn what is it more to send stuff into the mountains??? lol. Jim it will be coming out of denver terminal Service Center: DENVER, CO - DEN 5601 Holly Street Commerce City, CO 80022 Phone: (800) 800-7770 Fax: (303) 227-3960 Manager: Rich Menigoz
Jim, If it works I would just have my guy here powder coat it, he is a good customer of mine and friend so he gives me a great deal and I couldn't even buy the paint for what he would blast and coat the entire frame, control arms, cross member, diff, and other stuff for. I'll be able to take care of the brake set up (I own a NAPA store so parts are mucho cheap:Brow. I will get with you on getting this done pretty quick. If you could PM me with your phone # I'll call and see if we can get it going. As far as the blasting/coating goes what would be the harm of removing carrier and pinion (I have disassembled/reassembled 10 or so rear ends) and reinstalling just how it was set up? I got a dial indicator and am pretty confident I can get it set up. I'd need another crush sleeve but I can get it back together afterwards. Shipping to us is allways expensive, I guess cause it's always up hill to get it here.o No: Thanks Again, we'll see if we can make this worth your while. Rob
I would just assemble it with out a crush sleeve thus way you can just do that when you disassemble and reassemble it. How does that sound? All you will need to do is mark the left and right carrier shim packs. Jim
Sounds like that would work. What manufacturers are you using? If you could give me a run down on what's new, reused, etc. Send me that PM too when you get a chance and I'll see if we can get this going Monday or Tuesday. You give a warranty? Thanks, Rob
