Fox T-Bird/Cougar Forums

Technical => Drivetrain Tech => Topic started by: Kafer79 on September 29, 2013, 06:23:06 PM

Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Kafer79 on September 29, 2013, 06:23:06 PM
I have an 88 XR7 with the stock 3.08 and rear drums.  Been thinking about pulling the rear axle off a 87 TC with AOD in the local pick-n-pull yard.  The yard is asking $65 for the entire axle with discs.  Here's a picture of the potential doner:

(http://i750.photobucket.com/albums/xx143/kafer79/Axle_zps83a056f3.jpg) (http://s750.photobucket.com/user/kafer79/media/Axle_zps83a056f3.jpg.html)

I've got the tools and the skills to swap so no problem there.  I would probably keep my 10" drums based on the chatter in this post (yes, discs are shagier but I don't want to go through the brake conversion when my factory drums are fine for me):  http://www.foxtbirdcougarforums.com/showthread.php?35944-Turbo-Coupe-axle-with-drums&highlight=turbo+axle

So, is the TC the more desirable axle?  Will the 3.73 offer a noticeable difference in performance?

Appreciate your thoughts on the topic.
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Loaded87IROC on September 29, 2013, 06:32:11 PM
That's a pretty good deal for the whole axle.  Without knowing anything else about your combo, I would say it will be a nice increase in acceleration.  Why not use the discs and upgrade braking at the same time?
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: vinnietbird on September 29, 2013, 08:13:29 PM
Grab it !!!! Awesome swap for super cheap. Grab the parking brake cables and quads as well. Leave the shocks connected. They look new.
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: thunderjet302 on September 29, 2013, 09:48:28 PM
Another thought is just get a set of 3.73 gears and have them installed in your rear. Yes it costs more but if the Traction-Lok in the TC rear is bad you'll have to rebuild it, costing more money.
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Bob on September 29, 2013, 10:49:54 PM
Grab the quad shocks and mounts off the turbo coupe too..
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Haystack on September 29, 2013, 11:04:52 PM
I drove 206 miles today andvi still have 3/4 tank of gas.

my station wagon with the same engine, same transmission and a bit more weight with 3.55 gears would barely touch 20mpg.

if you cruise freeway a lot, I wouldn't do it. if you only play on the weekends and want to race, go for it.

my 2 cents.
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: 88turbo on September 29, 2013, 11:16:26 PM
7.5<8.8  swap it and dont look back....
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Haystack on September 29, 2013, 11:28:09 PM
being an 88 car, there is a chance he already has a 8.8.
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Kafer79 on September 29, 2013, 11:45:46 PM
Quote from: Haystack;422632
being an 88 car, there is a chance he already has a 8.8.

Yes, my 88 XR7 has the 8.8 with Traction-Lok and the rear quad shocks from the factory.
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Aerocoupe on October 01, 2013, 04:44:08 PM
Buy it for $65 and sell it to a Mustang guy for $200.

Darren
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: Kafer79 on October 02, 2013, 01:06:59 AM
Quote from: Aerocoupe;422727
Buy it for $65 and sell it to a Mustang guy for $200.


Funny!

However, for the price I'm thinking of removing that 3.73 pinion and carrier for a later swap into my 8.8.  Just need to determine what my engine RPM will be at highway speeds before I commit.  I've found a few good RPM/Gear calculators including this one:

http://www.differentials.com/technical-help/differential-gear-ratio-calculator
Title: Opinions Wanted: Swap XR7 3.08 Axle for TC 3.73?
Post by: mcb82gt on October 02, 2013, 10:29:57 AM
Mine seems around 2500-2600 ish.  AOD.