BoomTown96

I need some advise for rebuilding the rear end in my 96 GT. My mechanic, who is first and foremost my friend and would not BS me, says that the T-lock system has gone to trash and the dif. needs to be rebuilt or replaced. At the same time i would like to install 3.73 gears and use a 31 spline dif and axels. Is there anything else that I need in addition to the the dif, gears and axels in order to do the rebuild? The only experience I have with rear ends(aside from the ladies) is helping to install gears in an 8.8.

How much would I have to find a new rear end for in order for it to be worth replacing the whole thing? This is my daily driver so what kind of down time am I looking at? any specialty tools or extra parts that I need? My mechanical ability is moderate, as I have done a few replacement/ bolt on projects, assisted in rebuilding a motor from the bottom up, but have very little diagnostic abilty. Hopefully that gives you an idea of the little experience I have.

scottybaccus

Well, the Trac-Lock will run you about $400, plus a install kit with bearings (with gaskets and seals) that should be from $100 to $150, and the gears, another $150 and axles at about $400. All in, you are approaching $1100 to overhaul what you have to the specs you want.

A complete axle assembly can be had between $700 and $900, ready to run. There might be some trade-offs, like an Auburn limited slip instead of a locker, choice of gears, mileage, etc. You do have options.

I think 31 spline axles are overkill unless you drag race regularly with 400+ hp. The Trac-Lock might be rebuildable, but it may require sending it off. If you retained the Trac-Lock and it wasn't too big a deal to repair, you might be able to reuse your carrier bearings, assuming they are in good shape. If they were to be removed or the carrier replaced, I would just replace them. You will pretty much need new bearings on the pinion when you change ratio.

code3GT

Get an eaton posi with some gears and call it a day. No need for the 31's unless you are gonna be pretty serious. I ran forged 28's in the old silver bucket with 534rwhp and 650rwtq launching off the 2 step at 5500 rpms.

BoomTown96

Ok so 28 spline it is. Anything wrong with going all FRPP? For everything from Ford, dif, gears, rebuild kit, oil(Royal Purple) and friction modifier I have it priced out at $415. If I go with Eaton it adds another $300. Is it a question of how much RWHP and how often im at the strip? I would realy like to save the money but if its truely worth the extra $$$ than ill shell it out.

1SLO85. Any word on the question I had for you earlier? Is there someone else I should talk to?

BoomTown96

Just posting to get the thread to the top of the new post section. I would like to order the parts soon so If anyone could chime in on my last post I would very much appreciate it.

scottybaccus

I don't know that I would say get it all from FRPP. Name brands are safe. Just follow ford procedure (or gear maker) for installation, then break the gears in carefully, and they will last forever.

I like Richmond and Motive gears. Ford gears are really good. Auburn, Eaton, Detroit all have good diffs. Timken or equivalent (no generic) bearings. Name brand seals.

Jfsram

31 spline is the first upgrade I'd make to an 8.8, if I was to upgrade. The 28 spline is the weak link of an 8.8.

Cheap ones can be had from a scrap Explorer. Just rebuilt it with new clutches and you are ready for some drag racing with sticky tires. As mentioned by Scot, it's not a neccessary upgrade unless you are throwing some torque to it.

BoomTown96

Thanks for the tips. What kind of break in period am i looking at before I can get on it? Im jumping from 2.73s to 3.73s so i'll be a little anxious. I was planning on buying a CAI/tuner combo next but im now considering the tuner with the gears. Is my comp. gonna go nuts with the big jump or can i hold off?

BoomTown96

BTW sorry for the ignorance(and the double post) but thats why im here. I was lucky enough to experience a 2.73 to 3.73 jump in my fathers AC Cobra kit car with a 302. Huge difference in a car that weighs 2000-2200 lbs(not too sure), as it would be in any car.

BoomTown96

Bump

Rear end is making more noise recently, I might order the parts this week. I still have a couple questions.
Any other opinions on a FRPP diff? What do I need to do during the break in period? How many miles should I put on it before I get on it hard. Thanks