View Full Version : Rear Axle ID tag Translation

10-27-2004, 12:43 AM
Need a bit of help deciphering the numbers on the ID tag of an 8.8 disc brake axle.
From what I can tell the tag on the axle reads:
1st line: 431D
2nd line: 3SL55 88 8F22

I have some pics at

I read the info at
but the 3SL55 threw me for a loop.
Shouldn't it have either an S or an L not both?
Thanks for help translating


10-27-2004, 12:48 AM
should be posi 3.55, thats what is on my 5speed 8.8 axle in the back yard

10-27-2004, 12:57 AM
my :2c:
should be 8.8 355 rear. if it came from a lincoln it was a mark7 though, not a mark 8. im not so sure those lincolns came with 355s though. :dunno:

10-27-2004, 01:05 AM
mark7's could have 2.73s 3.27s i think, also the disks on back are bigger than tc disks, not to mension the caliper pistons are bigger.

10-27-2004, 01:53 AM
If you remove the differential cover you can count the number of teeth on the ring and pinion gears and divide the ring # by the pinion #. That will tell you what rear gears you actually have. The tag on the rear is the same one that's on mine which I pulled out of an 87 Turbocoupe with a 5 speed. It should be a 8.8 traction lock with 3.55 gears.

10-27-2004, 01:54 AM
First line... (431D) is the axle code that you can look up in the shop manual to get the info already on the second line(duhhh Ford).

Second line
3SL55 Traction Lock 3:55 (All the Turbo Coupes seem to have the "SL" in the ratio)
88 = 8.8" ring gear
8F22 = axle build day(June 22 '88), a rather late one(for a TC) I might add.

Disc brakes, 8.8" and 3:55s has to be from a 5 speed Turbo Coupe. None of the V8 cars(LSC included)had more than 3:27 gears from the factory.