View Full Version : Can a shadetree successfully swap gears?

04-13-2004, 11:45 AM
I have just ordered a set of 3.73s for my '95 SC automatic, along with a rebuild kit. I have a compressor, impact tools and hand tools, plus some mechanical ability, but I wonder if it's a good idea to tackle swapping out the ring and pinion, and doing the rebuild. Plus I know if I do, I'll need to find some special tools and measuring devices. What about it?? Anybody out there tackled this before and been successful? Around where I'm at (northern Alabama/Southern-middle TN), there are very few people around who do that kind of work, plus I hear it's really expensive if you find someone to do it. Sounds to me like something I ought to learn to do for myself AND others. Any advice? BTW, I also have a full set of factory shop books for the car.

Don Klitzke
Prospect, TN

Anybody know of a good '94/95 SC 5-speed for sale? Low miles, reasonable price, adult/geezer owned, non-smoker, garage kept preferred.

Rob Noth
04-13-2004, 12:19 PM
Don, I'd recommend not doing the gears yourself. It's not a shadetree job, it's not even a job that some general mechanics are willing to do. I had to find a rear end specialty shop around here to do it.

You can save some money by removing the center section yourself, and then just taking that in to the shop. That part is pretty easy. The factory manuals will have the procedure, but if it says to remove the half-shaft from the hub, you don't need to do this! Just remove the knuckle together with the half-shaft as an assembly, much easier. Some manuals say to remove it from the hub, which is a totally unnecessary step.

Jim Cook
04-13-2004, 12:20 PM
This is a job best left to someone who does it for a living. If you can pull the differential (not that hard) and take it to a pro, have all the parts, then it should cost you about $125. Be prepared for a wait though as most of the good shops are swamped once racing season starts.

04-13-2004, 12:56 PM
i've done about 5 gear swaps in fords and chevys. I basically have got it down to perfection, and none of the gears have made noise. However i also had ALL of the correct tools and measuring devices to do the job right. It does take a lot of skill however, and some time. If you mess it up..you'll be sorry. Also you need access to a press, and some special bearing pullers, inch lb wrench, ft lb wrench, pinion depth gauge, backlash gauge, run-out gauge, and marking compound. Even if the meaurements are all set up correctly, the contact pattern does the final adjustments and it takes practice to what the pattern should look like. I would take it to another shop and have them do it. That way if there is a problem you can bring it back and have them re-do it at their expense. Dont go to any garage...go to somewhere that does tranny swaps and rebuilds rather than some general mechanic. Most general repair shops will just throw them in and hope for the best. If you were located close to me, i'd be happy to give you a hand in setting up the gears.

04-13-2004, 01:02 PM
Here is a nice article i have posted before from the Corral:


While it is about a straight axle diff gear change, the methods are about the same.

04-15-2004, 08:47 AM
After talking to a few locals and reading up on it, including all of the helpful replies above, I decided to call Summit Racing Equipment and order the M-4001-M373 aluminum housed Auburn Traction Lock complete carrier. In the long run, it was not much more expensive than buying the gears and the rebuild kit plus labor to do the work. The added benefit is the traction lock. Everyone I talk to says it will make an awesome difference to have both wheels applying power to the ground. YEEHAAAAAAAAAAAA! Can't wait to get it installed, plus I'll have to get my chip reburned. Plus I also have a Pro-M MAF and throttle body coming too. Does anyone know where there's a black matted air intake tube, like SCP used to sell? I don't care for all the chrome stuff under the hood on my daily driver, too much work to keep clean, plus I just don't care for the doo-dad appearance, no offense meant.

Anybody out there with a clean, low mileage '94/95 SC they want to sell for a reasonable price, I'd be interested. Thinking maybe 5-speed, but the right automatic would be alright if it was in the condition I need. Thanks. :D

Don Klitzke
Prospect, TN

04-15-2004, 09:07 AM
i hate to break you're excitement, but you'll still need to set up the gear set exactly the same. Basically you've just purchases a ring gear bolted onto a posi carrier. That carrier will still need to be installed in the pumpkin, as well as the pinon. The pinon depth will need to be measured, bearings pulled on and off a few times to shim it up right, you'll need to check carrier backlash, adjust shims there, as well as check run-out, and still check the pattern. Everything that was stated in the above posts will still need to be done. Just because you purchases a carrier unit, you cant just throw it in and go. You also need to make sure that the new carrier is not for an 8.8 stang. The diff is the same and it'll fit, but the axles wont go in right. Must 8.8's are c-clip rear ends, where as ours is made for snap rings. The differences are the side spider gears and the recess in the gear to allow for the snap ring. Summit 90% of the time doesn't know the difference...so you better check on that ASAP.

Jim Cook
04-15-2004, 12:18 PM
I believe that what Don bought is the complete Cobra carrier set-up and it should just be a matter of swapping out the pumpkin. Unless Ford recently spec'ed the Auburn differential as an upgrade, it probably has a Traction-Lok diff. same as the one I bought in '99 came with

04-15-2004, 01:17 PM
Let us know what you got dklitzke. Did you get a whole carrier..or did you just get the carrier unit?