Rear differential/axle noise. Help!

[jbc4188]

I have a 94 Explorer Sport 2WD with the 5 speed manual transmission. My problem occurs after driving interstate speeds for several miles, when I get off the interstate and try to take off from a dead stop my explore will jerk and shake some and I hear grinding type noises coming from the rear of the truck, it also does it sometimes after shifting to second. How long I drive at highway speeds seems to determine how bad the symptoms are. After it sits for awhile the noises stop until I drive for an extended period of time again. Does this sound like the differential going out to you guys? It has the 3.73 traction lock rear end in it. I also hear popping noises from the rear of the vehicle sometimes, even when coasting. I've had the wheel bearings checked, but that's about it. Any information would be helpful.

 

[leebo]

I'd like to start off by welcoming you to the site. You will find anything and everything all right here.

As for your problem. Start off by checking you diff lube, and you u-joints. Either one could be the problem. If either one is acting up or low the power can't be sent from the trany to the rear wheels. Start off simple, then move up to bigger problems.

 

[yob_yeknom]

Sounds like Leebo got it.
You might want to consider rebuilding the limited slip and refilling with new fluid also. I'm guessing that a '94 will have enough miles on it to need that by now anyways.

 

[fordkrazy]

it sounds like if you hear grinding noises the friction plates on the traction loc are worn out or a spring has broken. more than likely its the friction plates since it dependes on how long you drive.

 

[jbc4188]

Does a rebuild kit for the differential include the friction plates? I'm going to try changing the fluid first, but think it'll probably need to be rebuilt. I'm Picking up a haynes manual today to see if this is something I can do myself, figure I'll replace the u-joints while I'm at it since they are so cheap. Also, any idea what a rebuilt kit will run me for the 3.73 traction lock? I really appreciate all the help from you guys, I've been driving sports cars for 7 years and have not worked on too many trucks so this website and user forum is a GREAT help.

 

[fordkrazy]

i dont know of any off the top of my head. its fords solution to a locking type diff. problem is it doesnt lock that well and you have to use special oil for limited slip. if you want to keep the trac. loc. diff. then you will probably have to get the parts from ford. look at your gears to see if they are wearing uneven. good gears will have smooth teeth with flat tops and will have only a very slight ammount of play so slight that you will barely notice it. there are also differential gears just like a regular diff. the only differance between the traction loc and a regular diff is the friction plates which are supposed to tie the axels together. you should check to see if the diff gears are good. they will have straight pointed teeth and should mesh fairly tight. there will be metal flakes in the oil and that is normal especialy since you have the trac loc. my advice is if your gears are bad then get a whole new differential and gears like a detroit locker or something like that. to replace what you have with ford parts will be as much or more as some kind of performance aftermarket system. there is a lot of options with the 8.8 rear end so check them out. also if i was you you should have a shop mess with this unless you have sucessfully installed gears before. if you dont get the pinion depth right your gears will be trash very quick.

 

[calcutta6]

lube it

My front differential had a leak in it. and i didnt notice it until i went to put it into four going up a hill and i got alot of popping and grinding
from my experience it may just need some new fluids

 

[fordkrazy]

since its dependent on how long he drives it, i think there is something actually wrong with it.

 

[yob_yeknom]

I think since it depends on how long he drives it that the fluid is probably low. The longer he drives it, the hotter it will get, and the more noise it will make. I could be wrong, but it would make sense.
I still say go ahead and rebuild the LS since you'll already have the cover off. No sense in doing it all over again. The rebuild kit basically is the friction plates, since that is what wears out and needs replacing.

 

[jimbo74]

forget rebuilding it just throw in a no-slip locker then you will have a true 2 wheel drive!!!!!!

 

[yob_yeknom]

BUT, a locker sucks to drive in the rain. Especially here with nothing but curvy roads and lots of steep hills/mountains where you have to be on the gas while going through those turns. LS is so much easier to drive and rebuilding it will be cheaper and easier. Two very important factors.

 

[jimbo74]

i thought with rebuilding a ls that you needed to have the gears re backlashed. that is a pain and not cheap. a lunchbox locker isnt that expensive and they dont use special fluid.

 

[yob_yeknom]

well...

It kind of depends on how mechanically inclined you are. Me and my dad rebuilt a LS a few years ago in the garage. I would say I'm pretty inclined (SAE certified technician) and my dad's very inclined (been a mechanic for many years). We were obviously able to set the backlash. It's been a long time so I don't remember exactly how it was done though. Couldn't have been all that hard.
I wouldn't say that installing a locker is the easiest thing on Earth either though...

BTW, the main reason I'm saying stick with the LS is for driveability in the rain, snow, ice, etc...

 

[SteveVB]

The No-Slip isnt a bad idea. Its a drop in design so its super simple to install . I have one and it is fine in Ice, snow and rain. Its not like driving an open vehicle, but once you get used to the understeer, and the chirps around the corners I think it is one of the best TADs out there. Ive driven a few detroit equipt vehicles that were bears to drive on any kind of slippery surface, and owhn some L/S equipt vehicles and the No-Slip handles much more like a L/S vehicle- that is until you lift a wheel or one has no traction at all- then it works like a Detroit. Very good product IMO.

 

[jbc4188]

Well, I checked the fluid today and it is definately low. I'm going to have it changed early this week to see it that fixes the problem. If a fluid change doesn't fix it I'm either going to try to find a used 3.73 traction-lock to replace it with or go with an aftermarket limited slip.

Steve - What brand l/s do you have in your Navajo? Also, I was wondering how much it cost you? Most of the ones I've seen are around 300.

 

[SteveVB]

I have the Power trax No-Slip in my Navajo, not a L/S. I have L/S's in my pick ups.

The no slip is around 400 but requires no special tools or labor to install if you can do it yourself. So the end cost is about the same or lower for a DIY No-Slip vs Prof installed Trac loc/auburn.

 

[fordkrazy]

hey steveVB. what is the differance between the powertrax lock right and the no slip traction system. i just noticed that the lock right is cheaper.

 

[jbc4188]

fluid change didn't fix

Well I had the diff. fluid changed tonight and it did seem to help some but I'm still having the same problem. The mechanic said the gears and all that looked fine but I forgot to ask him about the friction plates. I guess I'm going to try to get the dealer to look at it when the syptoms are the worst (after extended periods of driving) and go from there.