Cobra rear axle swap
 

Rear end in Cobra making noise. Sounds like bearings. But being that you have to take the center section out I am wondering about going to a solid axle. Question is other than the obvious axle choice which other vehicles have the same dimensions to replace it? I was talking to a buddy and he was telling the Explorers came with 3.73 rear ends and 31 spline differential. Also how about a Lincoln Mark 7 rear axle? anyone have a link for dimensions or past experience before I jump into this.
Thanks

Don't go there.

If you're going to swap axles to a live axle you need to:
1. know that your handling will go to shit unless you pony up for some upgrades. IRS beats the shit out of a STOCK mustang 4-link.
2. DO NOT go pulling out your whole IRS and going solid because you need bearings and think you can score gears for free.
3. If you do swap, use a rear from a 99-04GT, Bullit, or Mach1. If you use a 96-98GT/Cobra you'll need wheel spacers or it'll look all sucked in.
4. Exploder axles don't work in 99-04 axle housings, they're not long enough. The exploder diff will will work.

Here's what I'd do, as a former IRS swapper (went back to a live axle with PHB/TA):
Take your car in to have a new set of 3.73 gears put in. It'll cost about 400 bucks or so for labor. Now, when you take the car in take a full new bearing set, and gear install kit and 3.73 gears in with you. It's no harder for them to install those and they're going to want new bearings and shims anyway.

http://www.americanmuscle.com/rearendrebuild.html
http://www.americanmuscle.com/fopege3ra1.html

BTW, you need to know which bearings are making noise. It might not be in the center section. I've seen a lot in high mileage and hard used cobra's the wheel bearings can gall out really bad.
Here's a pic, I'm talking about #2.
http://www.trademotion.com/schematic...cal/FWP110.gif

Get one from another 99-04 Mustang GT or you will be having alot of fun trying to get it to bolt into the same place. I am sure you can find a local guy with a GT who would love to swap with you.

Thanks guys. I have a 04 Mach 1 and have contemplated swapping rear ends. Mine is an automatic and have thought the wheel hop might not be som bad with less HP? Fortunately my son works at a garage and I am going to get him to do the work. I'll let ya'll know how it works out.

With different bushings in the rear end, which when you install the IRS you need to do then!, the wheel hop is almost gone once you change out the bushings.

To rid yourself of most wheelhop you'll need to replace all 4 cradle bushings with delrin (500 bucks ish), and all the rubber bushings for the center section with Maximum Motorsports billet rear support and then make sure you have a good 650# or better spring in the back and a stiffer than stock (except for 03/04 cobra) set of rear shocks.

Check out MM's full IRS grip box. It's worth its cost in saved repairs.