So, my 7.5 is all fubar'd from a bad wheel bearing seal that let most of the juicy goodness dribble out on to the pavement. On top of that the pinion bearing was already bad and the gears have been howling for atleast 25k miles. I really have no desire to replace the guts of a 7.5 when I have access to a complete low mileage 01 Cobra rear end. So...that's my plan, swap 7.5 ok-ness for Cobra great-ness.
I figure an 01, while weaker than an 03-04 technically, is still more then strong enough to withstand the mighty, awesome, even fearsome power of my stock 3.8L.
Anyone already done this? If so, what issues did you encounter aside from the obvious driveshaft flange difference? Anything will help.
First off what year mustang do you have?? That IRS will only fit 99-04 models. The 01 Cobra IRS has 31 spline axles, i forget what gears are in it though. It will handle all the power you put to it from the mighty v6 lol. As for doing it im not sure, you will prob have to change the driveshaft, is the rearend complete with the rotors, shocks, springs, control arms?? If not you will have to get new ones and most likely different ABS sensors.
i dont know about this swap but i would really like to learn so please include plently of pictures when you do this swap this on my wishlist of things to do and a good write up would get me to do it faster ... good luck with swap
A good write up on this would do this swap justice.
So, bearing my new-found responsibility in mind, I will include pictures and detailed descriptions of the procedures, parts, problems, and any other p-words (and f-words) I can cram in to a PDF.
I am trying to get this to look like a factory install, like some guy in Dearborn "accidentally" put this IRS on to a base mustang...Ooops.
Oh, and yes, it has all the bits and pieces including rotors, calipers, e-brake parts, etc. I dunno what the stock ratio is, only that it hasn't been changed out.
Don't look for it soon though. It'll be a few weeks before I get started.
First off what year mustang do you have?? That IRS will only fit 99-04 models. The 01 Cobra IRS has 31 spline axles, i forget what gears are in it though. It will handle all the power you put to it from the mighty v6 lol. As for doing it im not sure, you will prob have to change the driveshaft, is the rearend complete with the rotors, shocks, springs, control arms?? If not you will have to get new ones and most likely different ABS sensors.
It will work on a 94-98, even a 79-93 if you wanted to go for the work. My friend has a Fox with a complete Cobra IRS/Mach suspension on it... It will just be wider than the stock rear's of those model years. The reason that the 99/01/03-04 IRS isn't that great is because it uses the same mounting setup as the SRA. It still handles well but Ford was in a hurry to release it so they did not do nearly as good a job as they should have. The IRS swap is much more detailed than a simple SRA swap, just forewarning you.
It's mine. I've got to go bring it to the car this weekend.
Oh, unrelated in a way, are there any particular problems bolting cobra calipers and discs on a v6? Rim issues aside...do I need to replace the bracket holding the stock caliper on to a cobra bracket? Or...is it just a bolt on.
Back to the issue at hand. Yes, the IRS could have been better, but it's not that bad as is. I wouldn't drag with it, but it sure helps in the handling department.
It's dirt simple. So far, I learned a few things that make the swap simpler...er.
1. Cobra rear calipers are the same as what comes on a v6 vert. (maybe everyone already knew that, except me).
2. The brake lines and e-brake cables are the same.
3. The driveshaft is the right length, but i need a new (larger) yoke for the driveshaft flange.
4. If you do the swap, you need the rear mounting brackets. The car already has the bolt holes, but the brackets are cobra only parts. Make sure you get them. (luckily I did)
5. Need new spring and shocks (duh) and that is the part that I am still researching. (taking suggestions). I don't want to lower it yet, just stock height for now. SO...i'm looking for stock 99 cobra vert springs, know anyone?
So far so good. I took alot of pictures and will put together something soon.
Planning a 7.5 -> Cobra IRS swap 
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