Rear Diff Swap..

[Blkstg2x]

What all is needed to swap out to a 31 spline differential? 31 spline axles and 31 spline differential..is that it?

BuyFordRacing.Com has some pretty good prices on this stuff right now...

$259 for the axles
http://www.buyfordracing.com/shop/pr...roducts_id=545

$219 for the trac lock diff
http://www.buyfordracing.com/shop/pr...roducts_id=543

[DevilSun]

Meh, not a big fan of the stock diff...but not a bad price. I'd say if you're doing that, look into a better (i.e. non-OE) diff. Then again, I'm always sayin stuff like that. As far as your question, I believe you're right...diff and axles are all that's required major parts wise, plus anything needed to install it all (good diff fluid and what not).

[2KRoushGT]

Just the diff and axles. You may also need new studs for the axles.

[Blkstg2x]

The 31 spline trac lock diff is what they use in the Cobras from the factory? I think that would be strong enough for me for a while..I'm really not into spending the $500-600 on an aftermarket Diff...However, If I found a decent deal on one..I might be convinced.

[jwhite]

hold tight on buying that 31 spline diff.
i am taking mine (31 spline) out of my car for a Torsen T2 diff.
PM me if you want to buy a used one...(about 15k miles, no slip, no issues)

[Blkstg2x]

Well..here's the deal...This is the LAST time I'm going to play around with the rear end..PERIOD. It just costs too much to replace stuff in there. So, unless it breaks after I upgrade to the 31 spline setup, it stays the same. That being said, I guess I could drop the dime on the Torsen or Detroit locker models, but I'm not going to install these pieces real soon...maybe sometime this summer. I was just looking to order some parts. Any further suggestions would be great too!

[jwhite]

Torsen T2 - torque bias ratio of 2:1
Torsen T2R - torque bias ratio of 4:1
Detroit TrueTrac - torque bias ratio of 3:1

Originally Posted by JTEKT Torsen

torque bias ratio refers to the "locking effect" of the differential. Specifically, it indicates how much more torque is sent to the high traction wheel (or axle) than is sent to the wheel with less traction. For example, a differential with a TBR of 4:1 sends 4 times the available torque that the wheel can maintain.

for what it is worth, Roush performance drivers were getting tired of the stock ford rear diff clutches wearing out and causing one wheel spins coming out of the corners...they decided to change to a Eaton Detroit Truetrac differential on the Trak Pak car...and according to one of the Roush performance drivers, the difference was night and day...a much more responsive car out of the corners.

the Eaton Detroit Truetrac is indeed a torsen style diff in that it uses helix gears to split the torque as opposed to plate style clutches (Ford Racing Traction Lok diff) to split the torque. the gears will last longer and are less prone to failure.

if your intent is to road race your car, a Torsen style (T2, T2r or Truetrac) rear diff will be a major upgrade over the stock differential.

the Ford Racing Traction Lok differential you listed above will be an upgrade over the stock differential but not as stout as a Torsen style diff.
if you just want to upgrade the rear axles and get a better diff, the Ford Racing traction lok diff will work just fine.

I will be taking the Ford Racing Traction Lok diff (M-4204 F318) out of my car soon and upgrading to the Eaton Detroit Truetrac...if you would like dibs on it, just let me know

[DevilSun]

Thanks for the info jwhite, I personally appreciate it as I was curious of the torque bias ratio between the three of those, more so where the detroit truetrac fell.