I have a customer who wants to replace his open unit in his 741 case with a posi, sure grip, my question is which new units and brand are good.He doesn't want a locker unit. I haven't changed or used a posi in a 8 3/4 in a long time I tried calling Cass at Dr. Diff but he is out of the shop until next week, so I'm asking on here for your help Thanks in advance

Use a Spicer power lok.

For street-driving, Auburn should be fine...

The factory put 'em in millions of vehicles...


Beyond that, Power-Lok...

http://www.eaton.com/Eaton/ProductsServices/Vehicle/Differentials/detroit-truetrac/index.htm For street use, the TrueTrac is best, better than an Auburn in my book, because it is more gradual, like one would need in actual driving.

The Powr Lok is the gold standard of limited slip clutch-type differentials and if you are mostly concerned about leaving two tracks on the pavement this is the one for you. Unfortunately there have been shortages of real Powr Loks in recent years. Some people have even taken to selling factory rejects because the demand is there. Of course they don't tell you the parts are rejects. DoctorDiff will sell you a real one if he can get his hands on one. The Powr Lok is rebuildable so a used one could be considered.

The Trac Lock is a lesser version of the Powr Lok and isn't highly regarded.

The Auburn uses no clutch material, just depends on the gear lube to separate the two parts of the cone. For that reason, and the fact it they was not designed to be rebuildable, the Auburn cone type limited slip is less valued by members of this board, at least.

If the car is 95% strip then a spool is most effective and low cost.

Hope this helps,
R.

The Eaton TrueTrac is the best because it is totally transparent in operation (no crow-hopping around tight corners) and requires no special lube. Just very spendy.

I had a similar unit in my '64 Polara called a Gleason Tor-Sen LSD for the Dana 60. I found it on E-Bay for cheap. Unfortunately, they are no longer in production from Gleason, but Eaton uses the same or similar design.

I have a TrueTrac and a Yukon bearing kit for a 741 case I am getting ready to list for sale. If you think he would be interested in it PM me.

don't know he don't want a locker. this is so nice to drive with on the street & to race with on the track. ignore the extra cap, i built this before MW had a cure.

I've been using the Auburn unit for 10 years without any problems.

First things first, the Gleason Torsen and the Detroit Truetrac are both gear type limited slips but the design is quite different. As there is only the Truetrac available for the 8.75, the subject is really inconsequential, but I like accuracy.

The Powr Lok is $395, Truetrac $575, both DoctorDiff prices. The Auburn is $469 from Jeg's. Maybe an extra $180 is spendy, I don't see it as such.

My choice would be the Truetrac as described in my last post, because I drive in the mountains a lot.

R.

They were garbage then , and they are even worse garbage now ...

DO NOT USE A CONE TYPE OF ANY KIND ...

I was just wondering how long it'd take for this message to come in.....................................................!!!

R.

i have the eaton true trac in my charger & it works great

Cass recommended the True-Trac for my car. Street strip 680 HP. I'm sure that's what he will tell you as well.

Damon