I was just wondering what's the fastest buick still using a posi unit. I just got off the phone with my chevy buddy who just exploded his arburn pro series unit, testing his new trans brake. Granted he was still using a girdled 7.5 10 bolt. He just wanted to tell that I was on borrowed time with my arburn unit which isn't even the pro series. I have a gn 8.5 10 bolt should be stronger, but I'm going to add a trans brake also. Should I go with a spool? 10 bolt posi users with trans brakes please dont be bashful!!!!!
The Auburn units will not hold up to a lot of torque. I broke 2 Auburn Pro Series posi units last year--I only raced my car twice :rant: . My car runs 11.40's with a 1.53 60'. I switched to an Eaton unit with the 800 ft/lb spring upgrade. I bought it from Randys Ring and Pinion out of Tennessee/Washington. They are one of only a few that offer this upgrade. Summit and Jegs don't even sell it. Do a Google search to find them. I paid about $330 for the posi and $80 for the upgrade. The posi itself was about $60 cheaper than Summit. No problems at all. I highly recommend the Eaton and Randy's Ring and Pinion. Tom Jenkins
Thanks Tom, I've been researching the Eaton unit with that upgrade. Glad to see it holds up to the punishment.
When I had my rear built I did alot of research and everything I read led me to go with the Eaton HD unit. Then....when I talked to Art Houser, www.rearman.com , and told him what I was doing and planning, He wouldn't sell me anything BUT a Eaton HD unit. He said the torque of a BB Buick along with the weight of my Convert. would kill any other posi if driven aggressively.
Stay away from using a spool on the street. A friend of mine broke a Mark Williams 40 spline axle due to street use. He was also running 15" M/T ET streets. There was no slip from a very wide sticky tire. Tom Jenkins
I was reading this tread and was wondering if anybody uses the Tractech's limited slip diff? There's an article in this month's Popular Hot Rodding. The one with the purple Challenger on it.
just don't base your decision on somebody's 7.5" posi blowing up, eaton or other wise they won't last if your hooking up with too much torque.......but you already made that comment in your original post so i guess you know....my z28 has an auburn posi(was already in the car when i bought it) and it's done fine so far, but i've only gone 12.5........we'll see what it does with the new tc!
Thanks for the input of all. I was seriously thinking of a spool.Some seem to be getting away with it. My car is a 83 buick regal with a 455. In Houston and neigboring areas it's imposilbe to get it inspected since the local news had and under cover investigation of places inspecting cars like mine. It will be a trailer queen, For the next 3 years until it falls off the radar after it's 25th birthday. With that in mind I was thinking spool. But the years do seem to fly by I also know that the 7.5 is no where near as strong as the 8.5 10 bolt. but I'm still worried on how it will hold up under a trans brake launch.
yeah, they aren't so great, but quite a few a4 ls1s are in the 11s, i think a few even in the tens....of course there are also those whose snap the first time the hook up stock too i'll let you know when mine gives
True enough, I know the LT1 is a real bottom end type motor, the 7.5 with slicks and some mods was living on borrowed time...I think the auto cars are a little easier on the rear, plus the LS1 makes the big power up top so might not shock the diff as much.... Get a TA cover, they do help. Hopefully you have no problems with yours. later Tim
I ran 10.40s at 3700 lbs with a Moroso "Brute Strength" posi. Traction was variable and it broke the case at the hub. Spool is much more consistent traction wise. If you don't run drag radials or wide tires on the street it works OK even in the rain. Been there..... A tight POSI is like a spool in the rain anyhow...... Bruce
Alan.....mine was older....said Eaton on it. I wonder if I can weld the carrier bearing stub back on? o No:
J.B. Weld it.....I hear its stronger than Gorilla Snot uzzled: ou: Ok...the old Moroso's were Eatons ?? I didn't know that. aren't the auburn units cone-based ??
Yeah, the reg Auburns were/are cone and junk. PRO series probably better. Put one in for someone and 50 13 sec passes/burnouts with slicks and it was history. Welded (no JB) the spider gears to "fix" it. :Brow:
The 2 Auburns I broke were both Pro Series. Buy an Eaton. A friend of mine runs 8.90-9.10 with one with the same 800 ft/lb spring upgrade I have. Tom Jenkins
