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Rear end problem!


Well-Known Member
April 6, 2008
Reaction score
City, State
Rockford, IL
Year, Model & Trim Level
92 pile
about 2 months ago, i swapped my 1st explorers drum rear end, for a disc rear end out of a newer explorer from the junkyard. only thing i took apart was the cover to empty the old fluid, and refill it when i swapped it.

well last wed my g/f calls me. saying the truck is making a messed up noise, and its the rear end making thumping noises when she drives. (i actually heard it in the background while she was talking to me even) i had her abandon it, and had it towed home.

well i just had the chance to actually look at it. 1st off, no spring? but the diff tag said it was a 3.73 lsd.. which is what my truck had originally, but obviousely with drums. thats wierd. but on the passnger side. i had probably 1/4th inch of in and out play. i also noticed when i turned the wheel, the small gear that the axle shaft goes into would move quite a bit and actually kind of move upwards it looked like. also, my new 1 month old gear oil, was black when i emtied it today.

well even though ive never done one thing rear end related, i pulled the internals out. everything visually is fine. nothing i can tell is damaged. so i pulled my old drum rear end apart. (realizing it had a aluminum diff cover!) and this one def has the lsd spring at least like it should. and i took it apart ready to swap the guts between them.

heres my question, am i going to be able to do this with them being different brake set ups? i did notice the axle shafts are different lengths. but i know that all these rear ends should be a 31 spline. so thats shouldnt be a problem in that aspect. int he rear carrier itself, the things in there seemed to have alot of play. i believe these are the clutch's, but im not sure. from examening the disc rear end, i think those clutch's(?) are bad, and toasted the fluid, and gave me too much play??

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no body knows workings of the rear end?

well i got my old internals swapped over to the disc rear end. still have to re-install the rear swaybar, and toss the rotors and calipers back on. it seems alot tighter then the set up i pulled. but wont really know untill i drive it.

im pretty proud of myself. with never taking apart a rear diff. i got two gutted, and swapped in 1 night. and dont even have a hayne's manual. lol

did u pull the whole ring gear out. if so did you set the back lash? or did you just take the side and pinion gears out? any pics?

Just make sure the ratios are the same front and hear. Did you use marking compound? Did you add LSD oil? The axle shafts are all the same from 91-01 so they'll be a direct swap. Axle bearing/seals are the same too obviously.

both are 373 lsd's. i obviousely checked that before i did the disc swap in the first place. whats marking compound? lol.

and when i 1st installed the rear end, i did add the lsd additive to the gear oil when i filled it. it was called friction modifier or something along those lines i believe.

i mainly just want to know if anyone's experienced something like this, and would know the cause? as i said, i have zero knowledge for rear ends. ill be finishing up the little things tommorrow morning. and then ill know if its all fixed or not. i didnt swap the pinion, so that might be an issue. but thats something ill find out. lol

well, i finally got time to finish it up yesterday. took it for a test drive. and didnt have or hear any issues.

today will be the big test though. have a bit over 300 miles to drive for work, and im going to be attempting to drive the truck for it to chicago.