97pontta

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.

Roadie

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.

97pontta

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?

Mike94ZLT1

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

Pro Built Automatics

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

rskrause

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

97pontta

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

Roadie

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.