Hey my buddy needs to get a posi for his 12 bolt in a 71 Chevelle. We did a search and did not find much info. What would you recomend for a daily driver and is somewhat low in cost? We tried the Chevelle BB's but they are slow as heck and there is not as much traffic as here so we hope to get info here instead.

Thanks,
Jason :)

I had good luck with the auburn I had in my 10bolt. The only things wrong with it were that A. it was a posi and B. it ws a 10bolt. They certainly are not the cheapest of the bunch though.


Charlo

I would guess an Auburn may work ok for a street car. They are not rebuildable and a friend of mine had them in his truck and I've seen it not transfer power to the other wheel many times in the dirt on basically easy trails! This was an Auburn Pro too! We are looking for something that will work well and last without causing the car to spin out easily in the rain like my buddies spool would do (even when coasting somewhat slowly thru a turn in the rain!). I'm thinking a Detroit True-Trac may work nicely--We need to check the spline count--guessing its 28 spline....

Jason :)

Try Randy's Ring and Pinion ( www.ring-pinion.com ) - I've had the Auburn in my K5 before I went one ton and Detroit and it sucked.............very easy to overcome with power (TPI406 motor). I hear Powerlok's are the tightest of the 'posi' style traction aid, but not sure if they are available for 12 bolts.

All stock 12 bolts are 30 spline

Detroit TruTrac?

Eaton offers a good "posi" ( not a gov-Loc ) for the passenger car 12 bolt. It has "5" small coil springs inbetween the side gears for pre-load. They are offered in various pre-load 400 lbs. / 600 lbs. / and 800 lbs. The case has a descent size ring gear flange also.

As said above try Randy's Ring & Pinion for a good price.

Some of the better ones that came in GM axles back in the day were those units(or very similar) made by Eaton.

My 87' IROC Camaro has a Auburn unit. Great cornering and still has bitchen power off the line with even power to each rear wheel. With a tight spring kit the car seems to washout in a corner under huge power.

Auburns are pretty good units.I had one in my jeep (yes I know, this is not a street car)but it gave really good traction at both wheels when needed.4-Wheel Parts will warranty the Auburn for life at the cost of $34 extra.

fi it must be a "posi" i would strongley recomend a tru trac

Try giving giving these guys a call. They are out of Santa Clara, and do awsome work.


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