differential problem??

[Skohler]

First post here. I have a 93 ford explorer 4x4 w/ auto tranny and have noticed that there is a noticeable drag on the car when driving. I thought the front calipers might be sticking so I jacked both front sides and the wheels spun without much drag. I went to the rear and thought maybe the brakes needed adjustment. I noticed that the rear wheel was very difficult to turn (in neutral) and when it did turn, the opposite side turned in the same direction, but not as fast. I remember doing this a few years ago and I "thought" the opposite wheel turned the opposite direction when spinning one by hand and both back wheels spun freely (in neutral). There was a slight movement in either direction that was easy to turn, so I figured the brakes probably were not sticking. I pulled some of the differential fluid out and it was like a thick black mud. I pulled out a few quarts and then added some fresh 90w semi synthetic gear oil back in. I am planning on removing the cover and trying to clean out the whole thing this weekend. My question is, does this sound like the differential is the problem given the condition of the fluid? I really don't want to start pulling out axles/gears/bearings. Maybe transfer case? The car has 107k miles and as far as I know (we bought it used @42k)) the rear fluid has never been changed, I know: shame on me. Do you have a recommendation as far as cleaning out the differential without tearing it all apart? Does it sound like the differential is damaged beyond a fluid fix. If the diff is shot, what is a ball park figure on replacing the parts. Any other things to try??

Thank you very much for your help,
Steve

 

[FMExplorer]

Steve,
If your tires spin in the same direction, you have a limited slip differential in the rear (a good thing). When you take the cover off you can double check this (you will have a spring or clutch pack inside the differential inbetween the spider gears). If you do have the LS, do not use synthetic oil - use 80W90 gear oil (5.3 quarts) and 4 oz of limited slip additive. Without the additive the LS won't work and it will be noisy as all he!!. You may consider replacing the clutch packs ($80 from Ford) if your fluid was this bad.

If you don't have a LS and your tires are spinning the same way - I have no clue what to do!

Let me know if I can be of any more help!

Jon

 

[Skohler]

Thanks Jon,

When we bought the explorer, the only thing I came across was that it had some sort of traction lock or different gear ratio from the factory. Do you think that the difficulty in turning the wheel could be due to bad fluid alone?? What I really am hoping for is that I can clean out the differential and the housing well enough to get any sludge out. One thing I forgot was when I pulled the drain/fill plug out, the inside of it had a thick coating of this thick sludge that looked like black grease. Is the clutch pack easy to replace? I have a haynes manual that guides me through most projects. Is there anything else you would check given the problem??

Thanks!
Steve

 

[Gary Steeber]

Skohler

I rebuilt my LS last month, this was fairly easy. It took me about 2 hours from start to finish.
I bought the rebuild kit from http://www.fordpartsnetwork.com/
The cost was about 73 dollars and it included the friction additive required for the LS.
The job is fairly easy as long as you have some mechanical skill.

 

[FMExplorer]

Steve,
Gary is right - easy job. Don't sweat it too much.

Your problem probably came from bad fluid. Rebuild the LS and change the fluid.

You may want to re-route the vent line up to near the gas fill. Get some hosing from the parts store - you'll need about 4 feet ($2). This will help keep water and sand out of the vent line and keep your fluid fresh.

Jon

 

[Gary Steeber]

Skohler,
This is the part number you will need when ordering the LS clutch rebuild kit, it includes the friction modifer.
Part #F5AZ-4947-BA
The cost was $64.99 plus shipping from Ford parts network.

 

[Skohler]

Just checked out the door label and I do have the traction lok differential. It made a mention in the haynes manual about the clutch pack associated with this traction lok axle, but no directions or anything. Are there any directions that come with the rebuild kit? I've been working on cars for many years so I might be able to dig in and figure it out, but directions are always useful. Thanks a million for your help. I'm going to order the repair kit tonight.

One last thing: I have just searched around the site looking for clutch pack. It seems as though the rear wheel should not spin freely as I thought, if it did, the clutch pack would not be working. What would happen if both wheels are lifted and one is turned. It seemed like the one that I was turning was very difficult to spin. Oh well, time to just crack the thing open.

Thanks again
Steve

 

[Jenkins1581]

I have a 96 XLT 4x4. I also have a Limited Slip. I resently changed out the fluid. All I used was 80 90w. And I have no problems. When I had the rear in the air both wheels moved in the same direction. Thats a good thing. Good luck on the rebuild.

 

[Robert]

In my '97 manual, Ford specifies 75W140 Synthetic axle lube for all 5.0L rear axles and all 3.73 & 4.10 limited slip axles. Everything else Ford specifies 80W90 conventional gear oil.

 

[yob_yeknom]

Originally posted by Robert
In my '97 manual, Ford specifies 75W140 Synthetic axle lube for all 5.0L rear axles and all 3.73 & 4.10 limited slip axles. Everything else Ford specifies 80W90 conventional gear oil.

Times change. Things change. Type of oil required changes. Before '97, 80W-90 regular gear oil is what you need. Why? I don't know, but the guys at the dealership parts department said there was some reason and double checked what year my Explorer was. In my '95 open diff, I use 80W-90 synthetic.

 

[Gary Steeber]

Skholer,
The clutch pack came with directions for the clutch pack replacement.
Pre 1995 differentials require 80-90 gear oil. Check your manual for your particular year.

 

[Skohler]

update

OK, took the diff cover off and besides having dark fluid, nothing looked bad. I'm not really sure how the clutch should look, but everything looks as though it is still in place (according to the haynes manual pics). No big chunks of anything hanging around in the oil. I removed both rear wheels and drums just to remove the chance that the brakes had anything to do with my original problem. I put one wheel back on (no drums) just to have something to turn. The wheel seemed to turn a little easier, but there is still a considerable drag. the drag is even greater when I try turning the wheel the other way (as if in reverse). The other side definitely spins when I spin one side so maybe my clutch is still good? If one side is kept from turning, the other side is much harder to turn than if both wheels were free. there is also about 1/4" of movement if I pull on the axle (both sides) as if trying to pull it out. If the bearings were bad, wouldn't they make a hum or squeal? Anything else to try or does everything sound like there really is no problem?

Thanks
Steve

 

[FMExplorer]

If you can turn one wheel while the other is locked down and not moving, your clutch needs to be replaced. You shouldn't be able to move 1 wheel without the other one turning (by hand that is)

J

 

[Gary Steeber]

Skohler,
The black nasty gear oil contamination is usually caused by broken down sediment from the clutch pack wear and no you can't see clutch wear from a visual inspection.
Like FMExplorer said if one wheel spins easily and the other doesn't then you are needing to replace the clutch pack.

 

[Skohler]

One last question.

If both wheels are off the ground (so that the clutch doesn't need to function) should it still be tough to turn one side or the other (both spinning freely) while in neutral? Keep in mind that the drums are off so the brakes offer no resistance.

Thanks for all the responses, they have really helped.

Steve

 

[Gary Steeber]

You should have only minimal resistance. Try disconnecting the Drive shaft and see if that frees it up.
If you still have too much resistance then I would go ahead and open up the dif, remove the axels and remove the clutches, then you will be able to inspect the Ring & pinion, clean it out and do a thourough inspection and verify that nothing is binding in the assembly. Of course you'll still want to replace the clutches when you're in there. All LS clutches wear out within the first 75,000 miles, yours are more than likely beyond their service life.
Also, you asked about end play on the axel shafts, mine had about 1/8 inch play on each side, apparently this is normal.

 

[Skohler]

I'll play around with the drive shaft. The wheel seems to spin MUCH better hand turning forward than reverse, to me it seems that this is a problem closer to the tranny than the differential. Any thoughts?

Steve

 

[Gary Steeber]

Have you disconnected the drive shaft, this will help narrow down whether it's the transmission or not.

 

[Skohler]

another update

Ok, purchased the clutch kit, pulled out pinion, the 'S' spring between the gears, pulled off the two bearing mounts on either side of the differential case. Now I'm stuck.

Does the diff case come out? the race will absolutely not come out of the housing. How in the world does this thing come out? Does the ring gear have to come off the case first?

Or, can I somehow replace the clutch pack without removing the case?? How would the side gears come out?

Thanks
Steve

 

[FMExplorer]

Steve,
In order to remove the carrier, you need a pry bar or similar tool. 1st - remove the bearing caps (2 bolts on each side). Be sure to keep them seperated and well marked - they can only go back on the side they came out of. After that, use the pry bar to remove the carrier. It is in very tight and will take a lot of force to remove. As you're pullin git out, take note what shims and spacers are where - they need to go back in exactly as they came out. After you have removed the carrier, you will be able to continue the rebuild. If you need to remove the center pin, there is an 8mm retaining bolt holding it in place. You would be well served to loosen (not remove) it prior to removing the carrier. It is held down with locktite and is very tough to break free. I broke 1 socket wrench and a socket getting that thing off. Be sure to use locktite when re-installing the retaining bolt. Let me know if you have any other questions...

Jon