Solved Differential Swap

[ThatOneGuy99]

I've kinda looked and it doesn't seem anyone has really asked this before, apologies if someone has. The gears in the front and rear diffs on my 99 explorer gave out recently, the shop wants $3600 for all new seals, gears, etc in both diffs plus a new axle shaft on the passenger side. Honestly I think that's insane so I'm looking at just putting used diffs in it and calling it good as I don't see these gears going out as a common issue and I'm pretty sure I know why mine did (don't drive on pavement in 4 low kids also with a bad flange on the rear diff). So my question is with the front diff do I need to mess with the torsion bars to drop the diff out? And I have an oil leak from the oil pan, would it be possible to access the oil pan so I can change that gasket while the diff is out? I haven't spent much time under the front part of the car, especially not specifically looking at doing this project. Any help would be appreciated, I'm at a total loss as to what to do, I'm 50/50 debating selling this thing and cutting my losses.

Also sorry if this is in the wrong subforum.

 

[RangerX]

I suggest you get a second opinion from a different shop. I can’t think of anything that would cause both front and rear gears to “go out” at the same time on a stock or near stock truck.
You can get a complete rear axle from a junkyard for a few hundred, and swap it out. The front diff is more involved, but really, be dame sure it needs replacing before going forward.
What symptoms are you having that made you take it to that shop? Does it drive?

 

[Fix4Dirt]

well, you just ordered the OMEs right now ya gottakeep it! as rangerx said, its highly unliekly they will fail simueltaneously. iirc i paid 800 for new seals, both axles, and bearings. imo 3600 is too much, thats like regearing and rpelacing everythign in the diff. much easier to just find a low mile used unit from the JY, and cause i know you take it offroad, freshen up the LS with an auto locker or carbon fiber clutches. the front and rear can be had for 200 each usually-ish, and if youre gettin front/back if they are indeed both bad, then i would get one with 410stheyre usually found in sohc higher trim ones on the 16 rims. to remove the front diff iirc you dont need to mess with the bars,theres a thread by member jefe on here that details it, but its mainly disconnecting stuff around it like cvs and stuff, no tbar stuff iirc. and have you got the ohv or sohc? the ohv has a one piece pan that iirc needs the engine lifted to change, but the sohc is a 2 piece so you can chsnge the lower one without lifting motor any.

edit: heres the writeup! How to: - removing front diff on a 95+

 

[C420sailor]

Yeah…fishy. Bring the truck to a reputable shop.

For comparison, my rear 8.8 lasted 330,000mi before rebuild, and I probably could’ve gotten another 10k out of it if I pushed it. Front is still going strong, she just needed some seals.

You can get rebuilt diffs for $1200ish I think? Rebuilding one yourself isn’t terrible if you have the know-how and the tools. But the tools are a bit of an investment. And having the space, too.

JY isn’t a bad idea if you’re looking to save $$$, but make sure you pull the cover (bring a drain pan and bucket for the oil) and inspect the fluid and gears first. Make sure the gear ratios match though….

 

[ThatOneGuy99]

Unfortunately I don't know any other reputable gear shops around me right now, I'd do it myself but I don't have a press to do the bearings. I'm looking at a set of diffs with 140K miles 3.73 gears for like $410. The front diff went first, started howling pretty loudly, and the rear diff is doing more if a high pitch squealing at any speed over 30ish.

 

[ThatOneGuy99]

Oh this thing is lifted with 31" tires on it, ain't exactly stock.

 

[Fix4Dirt]

Unfortunately I don't know any other reputable gear shops around me right now, I'd do it myself but I don't have a press to do the bearings. I'm looking at a set of diffs with 140K miles 3.73 gears for like $410. The front diff went first, started howling pretty loudly, and the rear diff is doing more if a high pitch squealing at any speed over 30ish.

thats a good deal imo! what gears has it got in it now? curious. i liked 373 with stock tires, with 31s, its meh now.

 

[ThatOneGuy99]

thats a good deal imo! what gears has it got in it now? curious. i liked 373 with stock tires, with 31s, its meh now.

Pretty sure they're 3.73 or 3.55 now

 

[Fix4Dirt]

alright, cool!!! but yeah, its a good deal imo. fwiw i would freshen up the ls or add auto locker since its gonna be "fresh"

 

[ThatOneGuy99]

alright, cool!!! but yeah, its a good deal imo. fwiw i would freshen up the ls or add auto locker since its gonna be "fresh"

Heh funny story, it's an open diff, thought it was LS but I guess not, if I go this route I'll probably throw a yukon dura grip in it. I was kinda thinking this wasn't common for the gears to shred themselves, I mean the flange going out on the rear definitely had something to do with it I suppose, do you think the tires could have something to do with it?

 

[Fix4Dirt]

Heh funny story, it's an open diff, thought it was LS but I guess not, if I go this route I'll probably throw a yukon dura grip in it. I was kinda thinking this wasn't common for the gears to shred themselves, I mean the flange going out on the rear definitely had something to do with it I suppose, do you think the tires could have something to do with it?

i suppose tires could affect it, but im pushin 330k on mine, had to put new seals in at 300. usually its stuff like lubrication, how old was the fluoid?, or backlash

 

[ThatOneGuy99]

i suppose tires could affect it, but im pushin 330k on mine, had to put new seals in at 300. usually its stuff like lubrication, how old was the fluoid?, or backlash

Fluid was replaced maybe 2K ago at the most, backlash I'm not sure, haven't actually checked honestly

 

[Fix4Dirt]

then that rules out lack of lubrication, so it could jsut be age and wear/backlash

 

[ThatOneGuy99]

then that rules out lack of lubrication, so it could jsut be age and wear/backlash

Well the shop said the flange was shot so my guess is the preload wasn't right and the gears weren't making good contact with each other, which kinda sucks because I had a different shop do the pinion seal and now that I think about it ever since then it shuddered on acceleration, kinda told myself it was the auto 4wd trying to kick in

 

[Mbrooks420]

Oh this thing is lifted with 31" tires on it, ain't exactly stock.

For the intents and purposes of your differentials, it’s stock. 31s aren’t really a load on these. I’d get the junkyard set and spend a weekend putting them in.

 

[C420sailor]

45 code = 3.55s assuming no one has been in there

 

[ThatOneGuy99]

45 code = 3.55s assuming no one has been in there

I'll have to look when I get home, my guess is 3.55 or 3.73 because it's just an XL fleet model OHV, but it did come with the towing package and other random things.

 

[Fix4Dirt]

it probably didnt come with 410s. if it came with the tow pkg, iirc they didnt make a 355 tow pkg (maybe they did, but i dont think), so its probabyl 373 like mine is.

 

[ThatOneGuy99]

it probably didnt come with 410s. if it came with the tow pkg, iirc they didnt make a 355 tow pkg (maybe they did, but i dont think), so its probabyl 373 like mine is.

I found some new diffs for $375 and they're 3.73 gears, I'm not disappointed in the 3.73s, I mean it's a 23 year old pushrod I'm not expecting a fast car

 

[ThatOneGuy99]

Mine is axle code 46