2005 Rear Axle Positraction

[Coubra]

We drag race our 2005 Bird and haven't got it to launch hard and have not found any positraction differentials being made for the stock 8" axle.
The easy/cheap solution would be to weld the differential but making it a "spool" but that takes autocrossing and closed track events out of the equation.
Would like to here any suggestions about modifications up to and including replacing the independent rear suspension with a 9" or 8.8" stick axle.

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[coat1971]

We drag race our 2005 Bird and haven't got it to launch hard and have not found any positraction differentials being made for the stock 8" axle.
The easy/cheap solution would be to weld the differential but making it a "spool" but that takes autocrossing and closed track events out of the equation.
Would like to here any suggestions about modifications up to and including replacing the independent rear suspension with a 9" or 8.8" stick axle.

Search out Sierra977 . Think he is on this site. Know him from fordthunderbirdforum but have no contact info. Has his car all tricked out for racing. Should be able to help

 

[coat1971]

Search out Sierra977 . Think he is on this site. Know him from fordthunderbirdnest but have no contact info. Has his car all tricked out for racing. Should be able to help

 

[Johnvins]

I was once told that 2001-2004 Mustang Cobra's offered a limited-slip and they would fit. And make sure to get correct splines (IIRC 27-spline instead of 31-spline)...perhaps finding one from a wreck is an option.

 

[Rusty_G]

I have a 2003 Cobra, and I don't think its diff would fit based on the diagrams I see. The mounts are very different. The Cobra looks like the diff used in the 89 - 97 T-Bird.

 

[inventz]

We drag race our 2005 Bird and haven't got it to launch hard and have not found any positraction differentials being made for the stock 8" axle.
The easy/cheap solution would be to weld the differential but making it a "spool" but that takes autocrossing and closed track events out of the equation.
Would like to here any suggestions about modifications up to and including replacing the independent rear suspension with a 9" or 8.8" stick axle.

The 1997 tbird has 8.8 independent rear suspension limited slip that has a locker option available i have a 1997 and a 2005 both are fun v8's. the 97 looks like it would fit the 2005 although the mounts are different.

 

[Sierra977]

A link to 2008 lincolnvscadillac eight-page thread of what is required to install an 8.8 inch limited-slip differential into a 2002-2005 Thunderbird (same as Lincoln LS car).
To begin, only a first generation 2002 differential carrier unit will work so your 2005 unit will not work.

Lincoln LS Limited Slip Differential bolt-in...

Well I decided to finally get off my tail and do some measuring today to see what ways a LSD could be installed into the stock Lincoln LS differential carrier. There were two other viable options that Jason and I had thrown around. 1) Do a powertrax unit into the stock 8.0" diff case. 2)...

www.lincolnvscadillac.com

There was another aftermarket solution from a California company however they say they no longer do the work for our cars.