Traction-Lok Limited Slip

[Nick]

I just found a traction-lok differential for a Mustang 8.8 rearend. It has 28 splines with this part number: Ford part # M-4204-F288. Will it fit in a 1985 Continental? What is the final drive ratio of a Continental? Will a set of 3.73 gears also for a Ford 8.8 rear end fit? They are from Moser engineering. How much should these parts cost? They are both brand new. Thanks for all the help guys!

[pro-five-oh]

Your Continental probably has a 7.5" rear so none of that will fit. You'd have to get a 8.8" rear axle assembly out of a Mark VII before you could put those gears in your car.

Right now you have either a 3.08:1 or 2.73:1 final drive.

[Nick]

Did they make specific Traction-Lok differentials for the 7.5" rearend or did people who optioned for the limited slip get the 8.8" instead? Is it expensive to swap the rearends?

[Lscman]

The 7.5" traction-loc differentials were used beginning around 1980 to present, but most were 2.45's thru 3.08 ratio. Most V8 and performance applications got 8.8" after 1985. I'll sell you a 7.5" traction-loc diff for $125 complete with 3.45's from a Mustang SVO, if you're interested. They have only 9,500 miles, since the car was totalled in 1988. That is an awesome ratio for all around use.
efrohner@hotmail.com

[ November 24, 2001: Message edited by: Lscman ]

[Nick]

So the 3.45s would help acceleration if my rearend gears were 3.08s correct? I'll check to see how much it would cost me to get a new differential and gears installed. How much do limited slips help?

[Lscman]

With 3.45's, you will get more torque multiplication and wheelspin at launch. Many mixed city/highway drivers choose 3.27, 3.45 or 3.55 gears. Weekend warriors that drag from light to light prefer 3.73 or 4.10's. With steeper gears, posi will be very important. If you simply spin one wheel, you won't accelerate faster. The price I quoted is fair for these low mile gears. Keep in mind you are getting a complete posi carrier and bearings with them.

[Nick]

Oh I'm sure the price for the parts is straight and true but I am only wondering about the cost to get them installed. Even without the new gears, do limited slips make a big difference in snow and rain?

[Lscman]

In Pennsylvania, I feel posi is almost mandatory for rear wheel drive for daily commute in snow and the car will launch much better when conditions aren't perfect (rain, gravel, oily road, ice etc). The difference is night and day. However, that's your call. I do my gear replacements myself and I have rebuilt my posi once for autocross racing. You will need to hunt around to find someone to install gears reasonably. Ford factory pinions are stamped with the shim requirements. Between your original pinion and a Ford replacement, you can calculate exactly what pinion shim to use with no guesswork. This means no pinion "setup time" is required, which makes the job easy. All you have to do is set backlash with a $15 shim kit and $12 Harbor Freight dial indicator. An independent shop familiar with the quick setup method (if you can find one) "should" charge around $250 because it is a 4-6 hour job.

[ November 26, 2001: Message edited by: Lscman ]