4.636 gears from an LS into a gen 2.5 with locker?

[nckwltn]

Is it possible to swap the 4.636 gears from an LS with 4.636 gears into my 99 with the 4.2xx gears?

I don't want to lose my locking ability, so can I swap over all of the necessary locking bits?


A local parts pick place has an LS with the engine and drive train yanked... should make it much easer to get the front out as I have access from top and bottom.


Although there is an SR at another parts place with 4.636 gears with a locker that I could pull the rear from.



I want to bump up to 33" tires, and figure that if I can swap the gears out, I might as well.



**UPDATE I've you stumbled upon this thread because you're thinking of doing the same thing, DON'T! Read to the end to learn more, but the short version is that the LS with the 4.636 gears have a 7.25" ring gear, while the SR that bolts more readily to the gen 2.5 uses an 8" ring gear. You want the 8" ring gear not the 7.25". The 97 LS may have come with the 8", but research it. A quick way to tell is to measure the outside of the diff housing. The outside top to bottom measurement of the 7.25" ring gear diff housing is only about 8"... so clearly an 8" gear isn't going to fit inside.

 

[stioc]

Can't speak for the mitsu diffs in particular but to do a gear swap you're only changing the pinion and the ring gear so shouldn't affect the locker. However, of course, not every ring and pinion gear will fit just any diff housing or the carrier.

If you can swap the entire axle or even the pumpkin it'll save you on the labor charges (assuming you and a buddy can do the axle swap) because setting up gear lash is best left to the pros. Also you'll need to buy new bearings etc to do the gear swap. Just some food for thought.

 

[billygoats]

Get the front from the LS, and the rear locked from the sr. The fronts are the same.


1999 Montero. Locked.

 

[nckwltn]

I should be able to remove the rear without taking the tires off, right? the SR has wheel locks, and I can't find the key. It looks like I should be able to unbolt the flange that holds everything to the axle from the back side... unless those nuts are welded onto the back side of the flange.

 

[billygoats]

You can leave the rims on. There are 4 bolts you need to remove holding the entire outside assembly in. You will need to loosen the bracket that holds thee brake cable. The just push, pull, kick or whatever to break the initial seal, the pull the whole tire outwards. The hard brake line will bind, but there is plenty of clearance to pull the axle out about 6" each side to clear the axles out if the diff.


1999 Montero. Locked.

 

[nckwltn]

got the gears pulled... is there any reason I just don't install them as is? I have the full front diff, and have the rear snout piece with all of the diff bits attached.


This seems like it would get around the difficult process of shimming and checking everything... Although, I would probably take it all to a shop to get inspected....


Outside of some seals and the likes... is there anything I should think about replacing before I slap everything into place?

 

[nckwltn]

Nice! Glad to hear you got it out! Sneakyninja's advice helped me out a lot too. Any issues getting it out? How about the front?

No real issues... was much easier than I thought it would be... Biggest problem was figuring out what I needed to unbolt on the front... Because the diff/axle mount was already cut, it came out pretty easy. and by undoing the ball joints, I was able to slide the axles out without having to undo the hubs.

The rear was pretty straight forward, 4 bolts for each wheel and a big tug pulled everything right apart... I had to disconnect the drive line, which for some reason was spinning (I think I left the t-case in neutral when I pulled the shift lever). I was able to use another wrench in the yolk to stop it from spinning. I also didn't realize that the entire diff was bolted into the snout piece. I'm glad I didn't take off the stabilizer bar, or it would have come crashing to the ground! and that rear piece is HEAVY!!!

 

[billygoats]

got the gears pulled... is there any reason I just don't install them as is? I have the full front diff, and have the rear snout piece with all of the diff bits attached.


This seems like it would get around the difficult process of shimming and checking everything... Although, I would probably take it all to a shop to get inspected....


Outside of some seals and the likes... is there anything I should think about replacing before I slap everything into place?

You can install the new front and rear in your car as is. Since the ring and pinion were not touched, there is no need to have them adjusted. Just change the front axle seals and bolt everything in. Sure helps to have a transmission jack because a floor jack does a terrible job at balancing the front diff at the correct angles.

 

[nckwltn]

Any tips on cleaning the gears up (and the housing)? carb cleaner? water and degreasing agent? Gasoline?

 

[billygoats]

Degreaser with brushes then brake clean

 

[jeep-N-montero]

Any tips on cleaning the gears up (and the housing)? carb cleaner? water and degreasing agent? Gasoline?

No need to clean the remaining gear oil off, I would actually avoid cleaning it personally and just add new oil when you install it.

 

[nckwltn]

No need to clean the remaining gear oil off, I would actually avoid cleaning it personally and just add new oil when you install it.

I was going to remove the front gears and only keep those, but as it was just as easy to pull the whole thing out, thats the way I went. I'm sure some debris from the parts yard got in, so I just want to make sure it's all cleaned up.


The LKQ, while having advantages like online inventory, and.... and... well, thats about it. I found the ground to be VERY dirty with little bits of debris strewn about. The U-Pick Parts on the other side of the 5 had a very clean lot. It looked like someone had gone through with a push broom just a few days earlier.


I'll probably do a little clean up, just to make sure nothing nasty gets ground up. I suppose that if these things (front from a 95, rear from a 94) have made it into the 140k mile mark, there probably isn't anything in them that is going to fail and strand me on the side of the road.

 

[billygoats]

I'm sure some debris from the parts yard got in, so I just want to make sure it's all cleaned up.


I'll probably do a little clean up, just to make sure nothing nasty gets ground up. I suppose that if these things (front from a 95, rear from a 94) have made it into the 140k mile mark, there probably isn't anything in them that is going to fail and strand me on the side of the road.

That's why I cleaned my rear up too. As careful as I was moving it around, I still had small bits of dirt that found its way to stick on the gear oil.

I cleaned up my front as I installed the lokka, I needed to make sure everything was clean to ensure proper mating surfaces and no gear oil on the bolts (locktite used).

I also cleaned the remaining gear oil out of my rear housing and used brake clean to wipe down the inside. Glad I did because that's where the teeth of my old locker ended up. I figured it couldn't hurt to get every last bit of old oil and residue out since fresh stuff was going in!

 

[billygoats]

When are you doing the install?

 

[nckwltn]

When are you doing the install?

I'll probably give it a go this weekend. I also want to do ball join on passenger side, and I'll probably do tie rod ends as well... then it's off to the shop for alignment and 33s..... Although, I kind of would like to see how the 33s and 4.2x gears feel... so maybe I'll have the new wheels put on this week, and then do the gears this weekend.... either way I know it will need alignment after the tie rod ends.

Also thinking about control arm bushings... I'm getting a strange pulsating in my brake pedal. It probably is related to rotors, but they weren't replaced that long ago... sometimes it's so strong (usually at highway speeds) that it shakes the truck quite strongly. Othertimes, it is only VERY faint (even at highway speeds).

at 130k on a '99, they probably need to be replaced, right?