Limited slip gear ratio

Want to check it?

First, if this is limited slip,

Chock your front wheels, no need in this puppy rolling away.

Lift both rear tires off of the ground,

Place your rig in neutral.

Turning a wheel forward will also turn the other one forward (same goes for rearward) They turn the same way.

(if this were a standard or non-limited slip differential, the wheels will turn opposite of each other)

1) If this is indeed limited slip the test is easier than for a regular differential.

2) Use chalk or tape and mark 12 o'clock on your tire.

3) Now lets mark your driveshaft at 12 or 6 near the rear U-Joint (don't really matter where-just so you can keep track of it)

This is easier with a buddy!

This is what should happen;

4) Very slowly rotate tire one revolution (tape is now at 12 o'clock again).

5) Your buddy is counting the tape on the driveshaft revolutions.

3.73:1 is really almost 3.75:1 (close enough for this test).

3.73 means the driveshaft turns three and almost three quarter turns for every one revolution of both wheels traveling the same direction (limited slip)

So,

6) Your buddy will count 3 full revolutions of the driveshaft and another 3/4s of a turn when you stop turning the wheel one revolution.

If this A 3.73:1 Ratio.

If it is not!

This method will let you know what it is (real close) By finding out how many turns the driveshaft actually made. (Example 4.10:1 would be 4 revs and a 1/10 of another)

Have I got you all confused and flustered?

Remember, a standard differential (wheels rotate opposite) will use a similar test with a few more added steps.

Let us know what you find out.

The Medic

There will be a small metal tag attached to the rear axle's center section under one of the cover bolts. The gear ratio is stamped on that tag. There were two axle sizes and five gear ratios available, with and without TracLok.

If you have the rear cover off, or if the tag is missing, the gear ratio is also stamped on the outer edge of the ring gear.

Hi CJ. I was typing again while you were posting.

Actually, I was hunt and pecking on this one while you were on the way to the library!

I could not find a single tag on a 'Mustang rear end on Google images, so I opted for old reliable- no doubt that way- even if ring and pinion swaps were made and and the "old tag" was put back on!

The Medic