I'm looking for a posi for my 9 inch. Here is the deal, I bought a moser housing and used a ford center section with 3.89 gears and a spool. The rear only has about 3000 miles on it and I am tired of the spool on the street. It’s really great on ET streets at the track but I'm only there 4-6 times a year. So I do need something that will handle the occasional beating.

I'd really like to run a posi of some sort but can't seem to find many options. I see Auburn has a unit and the Ford Trac-Loc. Would it be a good idea to buy an old trac-loc and have it rebuilt?

Powertrax has this on summitracing.com Part#PWT-92-0690-3100
I'm not for sure but I think that has to be used with an existing limited ship???

If anyone could help I would really appreciate it.

 

powertrax is a locker and is made to replace the guts of an open differential. There's a lot of options for 31 spline.

I have 35 spline axles and detroit locker... I don't like the detroit locker or a spool. I want to find a 35 spline open diff and put a powertrax in it. I'm just having a hell of a time finding the open diff -- it's an older F100/F150 performance axle option that was pretty rare.

 

So if I had the stock limited slip from the 9 inch I could buy the powertrax unit and have a gear shop set it up for me? Sounds like a nice option, mannered on the street and locker when racing. Has anyone here done this with the powertrax unit?

 

I have the Trac-Loc in mine and I like it, very streetable.

 

Detroit locker is the best of the posi's. But how much do you want to spend?

 

Before you go the locker route, drive a car with one. Far better than a spool, but still not nearly as refined or pleasant as a good LSD. I am not real familiar with the options available for the 9", I prefer the 12-bolt for a street car. But Randy's Ring and Pinion is a great source of rear end parts and info. I suggest calling them.

Rich

 

I checked out randy's ring and pinion and seems like a knowlegeable place.

A couple of other questions, I have a moser brand spool and gear set. These were set up by a local shop and have wined like hell from day 1. They wine from 30MPH on up and it doesn't matter if your on a pull, coast, it still wines very loud. Is this because I used a moser gear set? Would it be better to use a Ford Motorsports Gear set? I know other guys who have 9 inches and they do not wine, atleast not nearly as bad as mine. I am going to change gear raios when I put in the posi/limited slip, trying to decide what brand of gears to go with. Thanks guys

 

It needs to be an open differential, not a limited slip unit. It replaces the gears and pins inside the open diff.

The powertrax unit has synchronizing ability that the detroit lockers do not have. I've ridden in a jeep with one and it's a ton better than the detroit locker in my car.

Detroit lockers have some slack in the unit that is used to decide whether or not it's locked. I would not recommend a detroit locker for the street if you like throwing the car into corners.