Rear axle swap ideas

[Warren99]

I wanna swap in a better rear end with a locker to handle my ~400hp om606. All I really care about is I want the same width as my dana44, disc brakes, the same bolt pattern, and something easy enough to find in a junkyard or off marketplace. Maybe an 8.8 or a 9 inch? Any recommendations?

[Warren99]

I was kinda thinking an 8.8 from a 95-01 explorer

[Big_Mark]

A couple questions,

Are you gonna be hammering down with this setup?

What size tires do you expect to run?

 

Any axle housing can be cut down to a specific width, and you can figure out what standard axle shaft lengths are that get you over all axle width where you want them.

I went through 2 axle swaps on my Scrambler, Ford 9" (with two standard width axle shafts, 36" tires) and a Dana 60 (from a junk yard Ford 3/4 ton van 42"  tires), that one had a custom width axle shaft that I had to get cut and splined.

 

My advice is figure out what your end goal is, then build you axle plan from there and gather more info.

 

Hope this helps

 

[Pete M]

not sure even the exploder axle is up to handling a 400 horse diesel.   that's 60 territory. 

[Warren99]

32 tires and I'm gonna want 4.10s. Right now it has a dana 44 with like 3.55s. And I think it's more like 350 hp, no real way of nowing until I dyno it. But the dana 44 with a spool has held up to some decent street abuse so far. I'm only really gonna be doing mild offroading with it. I think the 8.8 should be fine. In the far future when the body gets more beat up I may get some one tons and cut up the fenders.

[ghetdjc320]

All depends how you wheel. A D44 in an MJ can easily handle it. My 8.25 is handling my LS with zero issues. Unless you’re running racing slicks with a weighted bed, you just aren’t going to get enough traction to kill anything. Exploder axles are a bit on the narrow side among other shortcomings … 

[Warren99]

18 minutes ago, ghetdjc320 said:

All depends how you wheel. A D44 in an MJ can easily handle it. My 8.25 is handling my LS with zero issues. Unless you’re running racing slicks with a weighted bed, you just aren’t going to get enough traction to kill anything. Exploder axles are a bit on the narrow side among other shortcomings … 

I mean the main thing is I wanna get a locker, and disc brakes. It just seems like its easier to swap in a 8.8 than convert my dana 44 to discs, and the 8.8 is a little stronger as far as I'm aware

[ghetdjc320]

26 minutes ago, Warren99 said:

I mean the main thing is I wanna get a locker, and disc brakes. It just seems like its easier to swap in a 8.8 than convert my dana 44 to discs, and the 8.8 is a little stronger as far as I'm aware

The 8.8 is narrow for an MJ and has an overgrown pumpkin of a center section. The disk brakes on it are petite. A JK 44 is a great axle. KJ 8.25 with disks is a good width. But a stock MJ 44 with a disk swap is golden. And the MJ 44 is a very strong axle. 

[Pete M]

just make sure you weld the tubes to the diff on that 8.8   

[Warren99]

1 hour ago, ghetdjc320 said:

The 8.8 is narrow for an MJ and has an overgrown pumpkin of a center section. The disk brakes on it are petite. A JK 44 is a great axle. KJ 8.25 with disks is a good width. But a stock MJ 44 with a disk swap is golden. And the MJ 44 is a very strong axle. 

I mean I guess I could just buy a disc conversion kit and a new carrier with a locker. Might be a lil more expensive but seems like it would be worth it in the long run based off what you said

[derf]

The 8.8 isn't really an upgrade over a Dana 44.  Not by much anyway.

 

You can upgrade the 44 easily enough.  Weld on a good truss that reinforces the center section.  You can put in a locker with 32 or even 35 spline shafts.

 

You can swap on disc brakes too.

[ghetdjc320]

1 hour ago, Warren99 said:

I mean I guess I could just buy a disc conversion kit and a new carrier with a locker. Might be a lil more expensive but seems like it would be worth it in the long run based off what you said

Truetrac is a great option with nice street manners and decent trail capability. Gentle on axle shafts too. Otherwise a selectable locker is great. Lunchbox lockers are finicky on the rear. 

[Eagle_SX4]

If you are keeping the 44 I have a Yukon Zip locker with 4.10 gears I just pulled out a TJ 44 I won't be using.

[Warren99]

23 minutes ago, ghetdjc320 said:

Truetrac is a great option with nice street manners and decent trail capability. Gentle on axle shafts too. Otherwise a selectable locker is great. Lunchbox lockers are finicky on the rear. 

I mean for street stuff I just wanna be able to do the occasional burnout, and get both tires to lock up if I try to slide it lol. For trail stuff I'm just doing light offroading for now to not mess up my rockers or fenders. Maybe its worth trying the truetrac out, it's like half as much as an e locker anyway

[Warren99]

8 minutes ago, Eagle_SX4 said:

If you are keeping the 44 I have a Yukon Zip locker with 4.10 gears I just pulled out a TJ 44 I won't be using.

Thats air operated right? If so no thank you, I'd rather install an electric one or a cable.

[ghetdjc320]

23 minutes ago, Warren99 said:

I mean for street stuff I just wanna be able to do the occasional burnout, and get both tires to lock up if I try to slide it lol. For trail stuff I'm just doing light offroading for now to not mess up my rockers or fenders. Maybe its worth trying the truetrac out, it's like half as much as an e locker anyway

Truetrac and similar lsds are great for street use and give excellent traction while still allowing differential action

[Warren99]

3 minutes ago, ghetdjc320 said:

Truetrac and similar lsds are great for street use and give excellent traction while still allowing differential action

I think I'll go with that then, or any worm gear style lsd.

[89 MJ]

3 hours ago, ghetdjc320 said:

The 8.8 is narrow for an MJ and has an overgrown pumpkin of a center section. The disk brakes on it are petite.

This. Especially the width is why I’d steer away from an 8.8. The Explorer Sport Trac is almost the same width as an MJ rear though. 
 

I would either stick with the D44 or order a brand new 9”. 

[Eagle_SX4]

1 hour ago, Warren99 said:

Thats air operated right? If so no thank you, I'd rather install an electric one or a cable.

Yes it is air operated.

 

I agree with the other comments about using a TrueTrac. I have one in both my Eagle and my Comanche. They are great. The rear end can get loose in the snow with a heavy foot, but it is very fun.

[derf]

I run TrueTracs in my Jeeps that are mostly street oriented.  You never know they're there.  The Jeep just handles snow and ice better.  And there's no clutches to worry about so it lasts forever.  Just don't put in gear oil that has limited slip additive.  It messes with the helical gears in the TrueTrac and reduces how effective it is.  The limited slip additive is for clutch style (OEM style) limited slips.

 

It should let you do a nice dual tire burnout.

 

If you're doing serious rock crawling where you lift tires off the ground, a selectable locker is a better choice.  Auburn Gear makes one that's a lot less effective than true lockers.  I had one and I'm glad I got rid of it.  I put in an Eaton Detroit E-Locker instead and was much happier.

[Warren99]

Alright I've decided to just convert my dana44 to discs, and get an e locker and some 4.10 gears. For the HP dana 30 in the front, do I need reverse cut gears? I know I need a bigger carrier to go from 3.55s to 4.10s.

 

Also, so far this is the only complete disc conversion kit I've found for a dana 44. https://www.quadratec.com/products/12700_414_07.htm?gad_source=1&gad_campaignid=19480551502&gbraid=0AAAAAD_wpjgLBBsqXjg6KO5t0CeUypgYR&gclid=CjwKCAjwnvTUBhBoEiwAZNDxZyCJqWfRhU90aVGzj7Layxg4_wGGejMCb1h-SP6oQKA02fwnlzizlBoCeUoQAvD_BwE

Does anyone recommend a different one? Or know of any cheaper ways before I pull the trigger on these?

[Eagle_SX4]

Check out this thread. They used Explorer brake parts.

 

 

Also others have used Crown Vic brakes.

https://naxja.org/threads/dana-44-disc-brake-conversion-crown-vic.1045256/

[Eagle_SX4]

Also if you convert to disc you will probably want an adjustable proportioning valve to set the rear pressure correctly. Wilwood makes a great one.

[ghetdjc320]

Keep in mind that you could also go with the wilwood big brake kit for the D30 with the 89- knuckles. The D35 rear kit can also be made to fit the MJ44 with a couple of extra parts and some simple adjustments

[Warren99]

16 minutes ago, ghetdjc320 said:

Keep in mind that you could also go with the wilwood big brake kit for the D30 with the 89- knuckles. The D35 rear kit can also be made to fit the MJ44 with a couple of extra parts and some simple adjustments

Yea I do plan to upgrade the fronts at some point as well. Right now I'm just sorta in a rush to get 4.10s in for an upcoming offroading trip my brother and dad are trying to organize. I'm leaning more towards just getting the quadratec kit for the rear, but to be honest I may just hold off on touching the brakes right now and just do gears and the locker.