Anyone familiar with "True-Trac" on a 9" rear?

[CaliCobra]

So, I'm going through my cobra, and came across the problem that I have bad axle bearings. Upon pulling the axles off, I discovered that they were 28 spline, and had a nice groove cut into them from the loose axle bearing.
I decided to bite the bullet, and upgrade to a 31 spline axle, so I now am researching changing out the differential on my Ford 9"

I read a few posts from fellow member Double Venom and he thought highly of True-Trac. Has anyone ever used this setup? Is there a better setup than this for a cobra with a 4 speed top loader, 429 ci.?

I've looked at detroit locker and it seems that they're kinda squirrelly if you don't know how to drive.

I've also discovered that the Ford Posi-Trac has a habit of cracking around the clutch housing or "hat" as I've hear it referred to.

Any info on these or other differentials would be greatly appreciated. Thanks!

-Gio

[WTN4Racing]

I've used the "true trac" type, 9" rear end for about 11 years now in a 66 Mustang.
It works great! no problems at all. You just lay down the power and it gets it to the ground with no clunks, bangs, or snap oversteer.

Respectfully, Gary

[DaveR]

I've got a truetrac in my 9", and it works well on the street and on road courses.

[CaliCobra]

Any problems with the use of true-trac on hard curves? I've heard that a detroit locker style of rear end will automatically cause a tire to break loose on a curve because of the 100% lock-up and equal revolutions on each tire when accelerating.

Also, any problems getting it to lock on a stright away, hard acceleration (such as a signal light to signal light race )

[CaliCobra]

Your experience would be greatly appreciated.

[trularin]

I have 31 spline axels with traction loc 9" and am quite pleased.

May I suggest you make sure the "pig" is setup correctly with the ring and pinion giving a good pattern.

If you are using the Torino bearings, you will need to make sure the retainer does NOT crush the seal into the axel, but seals the housing.

I went through three sets of seals before I stopped the leaks, I pressed the bearings myself the last time.

Also, the 31 splines are much larger and weigh more...if weight is a concern.

Hope this helps.

[Jac Mac]

Originally Posted by CaliCobra

Any problems with the use of true-trac on hard curves? I've heard that a detroit locker style of rear end will automatically cause a tire to break loose on a curve because of the 100% lock-up and equal revolutions on each tire when accelerating.

Also, any problems getting it to lock on a stright away, hard acceleration (such as a signal light to signal light race )

We use one in a car similar to a cobra-- 9"IRS etc. Absolutely Magic, no snatch, predictable,etc. Next to that I would like to try a DPI , If its better than a T/T it must be fantastic. Our car is raced on road circuits and True-Trac has been trouble free.

Jac Mac.

[mdross1]

The 460 in my car has not hurt the TT at all.Just pulled the pumpkin to regear 3:70 and change out iron center section to aluminum made by Strange.