98 Explorer Rear diff (LSD)

[sachurch]

Hi,
I started having problems with the rear diff becoming "ratchedty" (sp?) at about 70,000 miles. Tried changing the fluid, adding the modifier, etc. on a few occasions. It never seemed to help. It only ratchets real bad when hot, and pulling into a parking space (or making slow, sharp turns). Last night it felt like I had it in 4 lw on dry pavement! The front didn't want to turn, was "skipping" or sliding, and the rear felt horrible! I just pulled the rear cover off the diff. The fluid was very brownish, didn't look good, and I could see metal flakes in the oil. More like dust, pretty fine particles. The diff gears looked OK, as did the R&P.

Now the question.

Whats wrong? I can't see the plate surfaces yet, but would assume they look horrible, based on the fact that these diffs have been known to have this problem. However, my local shop said it sounds like the diff bearings (the tapered roller bearings) are shot. He said he has seen that alot, and did not seem too aware of the LSD issues. I could not move the front of the pinion shaft axially at all, so sort of assume the pinion bearings are OK.

The other issue that occured last night was that the 4WD High and Low lights were flashing on the dash, somewhat intermintently, but seemed to do it most during coast-down periods, regardless of speed. Completely didderent issue? Or is the computer somehow confused because the rear diff is all goofed up and it thinks it should be trying to engage it in 4WD? Or am I way off base?

Also, it is easier to replace the entire rear end from a junkyard, or just rebuild the diff? I do alot of transaxle work, so this is right up my alley, except I have never dis-assemled one of these.

All suggestions would be greatly appreciated!

Scott

 

[sachurch]

After further inspection, I can move the diff side to side quite a bit, meaning the diff bearings must, in fact, be shot. There seemed to be excessive backlash (caused from bad diff bearings)as well.

Can the diff be serviced in the vehicle? And how do the "S" type clips get removed?

Thanks.

 

[Sams01XplrSprt]

welcome scott

 

[HahnsB2]

Yes you can rebuild it but I wouldn't recommend it. It's a time consuming ordeal and you need some special tools. Swapping the whole rear end is easier and usually cheaper.

 

[jlsparky7]

Welcome. I was gunna suggest backlash but you figured it out on your own. Good job.

 

[Dopler174]

Try some Friction Modifier fluid first. It will cost about $20. If it doesn't work, all you have lost is some time and $20.

 

[HahnsB2]

Try some Friction Modifier fluid first. It will cost about $20. If it doesn't work, all you have lost is some time and $20.

The carrier bearings are toast man.

 

[sachurch]

Having different issues now

Thanks for everyones help! The carrier bearings were bad. I replaced them as well as installed new clutch discs in the diff. The car turns sharply very well now (finally).

However, on occasion it feelsas if the car is in 4wd high at times when turning into parking spaces, etc. It is only intermittment, however. 4wd high and low work just fine when I turn the switch on the dash. It goes into, and out of both ranges. The dash lights don't always come on when 4wd is engaged (either range). But sometimes they do. However, when driving normally, the 4high and 4low lights will blink on the dash for a little while, then stop blinking. I know there must be something wrong, but what? For whatever reason, the car (ECU) feels it needs to be in 4high sometimes when turning into parking spaces.

Any ideas?

Thanks,
Scott

 

[turboexplorer]

Thanks for everyones help! The carrier bearings were bad. I replaced them as well as installed new clutch discs in the diff. The car turns sharply very well now (finally).

Thanks,
Scott

Glad to hear that fixed it You do it your self or did you have a shop do it?

 

[sachurch]

Yes, I did it myself. Wasn't too bad, except dripping diff lube all over during fill-up! Thanks for eveyone's help.