'97 5.0L AWD Limited slip rear differential

Joe, I have a 97 Exp EB with 302V8 AWD and 3.73 gearing and have changed the same seal successfully. Some comments:

1. There is a small tag bolted onto the diff cover that the dealer can ID the correct parts. Has never failed me.
2. Mine is a "Limited Slip" which means it has clutches. I don't think Ford provided a "locking" diff for these cars -not sure. The service manual has a test to see if the clutches are working. Involves disconnecting the driveline, jacking one rear wheel up and measuring torque to rotate the wheel. I think it must be 20 ft-lbs or more.
3. The driveline yoke can tolerate some wear ie a groove. Polish it out very smoothly and make sure new seal will seal effectively b4 installing. Oh yeah, make sure you get the proper preload in the yoke spindle nut. There is a procedure in the service manual.
4. Lube - now thats a story in itself. I had Randys Ring and Pinion in Seattle tell me to use ordinary "dino" oil of correct weight and MAKE SURE to add the Ford friction Modifier (Ford PN M-19546-A) because if the limited slip clutches. I'm still using synthetic only because the guy b4 me put it in at 100k miles. But, still need the modifier.
5. No recommendations on the Front diff lube. Book says something about '4 X

4 Fluid" .Transfer case does use Tranny fluid. Wouldn't hurt to change. Easy to do.

1. While I'm on subjest, I've changes 4 or 5 diff seals in my life and never had a leaker even with a small wear groove. Never likes to see but almighty $ prevailed. New parts are definitely flat w no groove. Hey - Good Luck.

Thanks for the comments. I finally did get the correct part. I'll keep the tag in mind for next time. But I have the same setup that you do (except XLT). The part they ordered was the correct part, and I fought with it last night.

The strange thing is that when I removed the driveshaft, I got some fluid dripping out. Then when I removed the yoke nut, I got a little more. It didn't look like the fluid leaked out from around the seal. The one thing I was not sure of was how far to force the flange into the spline. It's a TIGHT fit, and after using a block of wood and a hammer, I ended up putting the nut on and cranking it. I got it so the teeth are almost flush with the groove on the flange that the nut sits against. I wasn't sure how much force I should put on it. And I also was scratching my head trying to figure out how the fluid could have leaked THROUGH the teeth.

I saw somewhere that you are supposed to change the nut when you do this job, but I didn't get one. Should I? I need to go out this morning and see if it is holding. When I did the seal, it lasted 2 weeks with no leaks, but the seal looked fine when I took it apart again.

I'm running some cheap limited slip fluid now, until I know it's holding. Then I'll change it out again and refill with the Amsoil synthetic. They say you don't need the friction modifier, unless you get clatter, so I ordered some in case I need to add it.

-Joe

Aha! That is EXACTLY what is happening. So, now I have a shiny new flange in there that I probably did not need. As for the torque, I'd love to know what it is supposed to be. My manual, best I could tell, says 15 ft-lb, which sounded real low to me. Anyone have the real number? I don't see any type of crush sleave, but wonder if there is something special about the nut. It has something orange on the back of it where it contacts the flange. I was wondering if this was a seal of some sort at one time and I need to replace the nut, or if I just need to crank it down.

OK, I give, how do you measure bearing pre-load??

Thanks,

-Joe

If it's the crush sleeve type you were supposed to measure how much torque it took to REMOVE the nut. If my memory is correct it's in the

200 ft-lb range. Then, IF you reuse the same crush collar, you retorque it to whatever you measured when you removed it plus someth>

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Yikes! I did just about everything that the procedure said NOT to do, other than using power tools (didn't do that). I hammered the crap out of that flange to get it on. Then tightened with the nut. There *must* be a "collapsible spacer" integrated into the pinion nut. I think I need to get a new nut. But, since I never read the torque setting when I removed it, I need to use factory spec, but the procedure does not specify what that is. The procedure also doesn't show the magic tool they use to install the flange, so I'd love to know how you get it all the way on without using drastic measures.

I've got several hundred miles on this thing, so hopefully I didn't do any real damage yet, and can just replace the pinion nut for 100k miles more of service!

-joe

differential.