Rear End in my 5.0 i need some help!!

jfran430

New Member
Jan 8, 2007
36
0
0
Connecticut
I have a 1990 gt and i dont think its a posi, but then again it could be, it is a stock rear end and i have no idea about the rear end. I want a posi but not if I already have one on the car. Anyone with information please help me out.
 
Trak-Lok

If you car is indeed a Mustang GT or 5.0 it came from the factory with a limited slip differential. Please do not use the word Posi that's a General Motors term.

If you are getting the one wheel peel out with your mustang the limited slip differential needs to be rebuilt. The will need to purchase a traction lock clutch pack for the rebuild. The kit cost $49.00 and the labor for someone to install it will run you a few hundred.

Or you could go buy another 8.8 rear end for a $150-$250 depending on where you look.
 
Thanks alot and sorry about the posi term. I though that both wheels should pin though but when i pull a shot only one wheel smokes and it was really frustrating. But all i should need is that one aprt and I'll be goo to go? Thanks alot i appriciatte it.
 
Check to make sure your car has an 8.8" rear to start with. In case someone swapped in a 4 cyl 7.5" for some reason. If it's an 8.8", just get the rebuild kit and have it installed. The installation will be rather costly. If you have stock gears, I would recommend getting gears and having them installed at the same time so you're not duplication labor. That is if it's in your budget. I wouldn't recommend doing it yourself unless you really know what you're doing. There's a lot of precise measuring to shim the differential correctly.
 
Well would I want to put 3:73's in as well and that sounds like good idea, but rather than the rebuild kit does anyone think it would be cheaper to just put in a used rearend? Mine does have 160,000 miles, and between the gears and the rebuild kit and labor it will probably run me about 500. Would it be cheaper and smarter to just replace the whole thing, from something with fewer miles??
 
i dont think so.

I would have it rebuilt by a mechanic who specializes in rear end work. Not someone who says they can do them, But good mechanic who checks all bearings, seals, and during the install correctly align and shim everything to spec.

What happens if you get a rear with 120K and its posi is shot also or bearings are bad? You just wasted $200-400 on that installed used rear end.
 
limited slip differential,Posi we have neither of these its a traction lok....first as said above you need to ensure you have a 8.8 rear end then you need to confirm the gears that are installed in your stang they could be 3.73s....if not you can purchase some used ford racing gears and a ford traction loc rebuild kit and bearing kit off e-bay to save some money and pay a mechanic to install them...thats what i did last year here are some links below for parts and for best results also replace the axle/wheel bearings you can get them at your local auto parts store

http://cgi.ebay.com/ebaymotors/Ford...1QQihZ012QQcategoryZ33731QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/ebaymotors/Ford...ryZ33731QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

http://cgi.ebay.com/ebaymotors/Ford...ryZ33731QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
 
Yeah, I would just rebuild your rearend. Do you know for a fact what the car has for gears? If not you can jack up the rear-end and spin the driveshaft to figure out what you have. Just mark the driveshaft and count the number of times the driveshaft turns to complete one revolution of the tire. If it turns about 3 times you have 3.08s, 3-1/2 times you have 3.55s, etc. You can also pull the cover and it should say on the ring gear, but that's not necessary. Do the trac-lock rebuild, gears (if you don't have them), and replace the bearings while you're there like stated above.
 
It has 2:73's its a completely stock rearend, its just old. Thanks for all the help everyone. I live in Connecticut so i am going to just make a run to Mustangs unlimited when the spring comes around. I would rather buy from there than anywhere else, that way i know exactly what i am getting.
 
i installed an axle(went from 7.5" to 8.8") 2 nights ago in 4-5 hours, thats with some BS and helping my friend install my old 7.5 into his car(he didnt have trac-loc but my old one did) he didnt finish his car until a few hours after i left, but i assume it took the same amount of time but probably longer because he's not as experienced, and had rusty brake line nut problems

~Mark~