what diffs should i run? help please!!

alright so i want to run 35's maybe bigger in the future. i HAVE a ford 8.8. i was origionally gunna swap in the 8.8 and leave the front 30. but i wouldn't mind swapping out the front to something different aswell.but tell me what you guys think should i swap in the 8.8 and leave the 30? or should i buy different axles. i know a guy that has a 79 bronco with a 44 and a 9". should i sell my 8.8 and swap in those diffs or just do what i origionally planned on doing? any help appreciated

Well, if you plan to lock the 30 you ought to truss it as well for 35s. I think the 44 would need trussing & building as well if you wanted to go much past 35s. Check out the FAQ / Stickies section here, CRASH has a great writeup on front axle tech & limits.

What tires/ lift are you running now? An 8.8 is a very easy swap. A HP 30 and an 8.8 is perfect for 33's and can hold 35's if your careful.


Whats the condition of the Bronco? 79's were sick trucks!

Right now im running 2 inch lift with 33s dana 30 and 35. The body of the bronco is shot (rust) only thing that is worth anything to me would be the 44 and 9 inch. But i think i might just swap in my 8.8 and upgrade the front 30

The 78 and newer Ford front axles really aren't good for swapping due to the Cast in radius arm mounts. Google Mr.N. and look for his Dana 44 write up. As far as the 8.8 goes, I think you guys should give it more credit. I have built SEVERAL customer rigs and have done 8.8 swaps in most of them. Even with stock 31 spline shafts you aren't going to break it on 35s unless you are a staight up idoit that can't drive. I beat the snot out of mine (with stock shafts) and have had no issues on 35s. And yes its locked: ARB. The stock hafts are 1541H just like a lot of aftermarket shafts, so its a solid platform even in stock form. Built up they can handle up to 38" tires with ease. My all time going shop motto is that you will never outgrow an 8.8 in a full bodied XJ.

The 30 is sorta a turd. Built right with a good locker and good shafts (alloys and super joints or RCVs) and you are ok with 35s, but anything above that and you will brake it sooner or later. The ultimate swap is a HP Dana 44, but it pretty much has to be 77 or older so they are hard to find. Keep in mind that a D44 can handle 35s pretty easily even in stock form, but its a lot of work to swap one in, and unless you go with a low pinion waggy, you will need to narrow it down or run a full width rear. PM me if you have any questions, these things are right up my alley.

That 8.8 will do ya just fine, done right an 8.8 can be just as strong or stronger than a 44. The 30 in front will be mostly safe up to 35s. If you plan on going bigger than 35s, take that Bronco's 44/9 combo.
I'll be putting a 9 in mine here soon.

So the "waggy" 44 is the same width as my 30 ??? Is it the same bolt pattern aswell? Thanks for the help you guys sure know what your talkin 'bout!!

The HP30 is plenty strong for 35s if you run chromo shafts and truss it. Imo I see no point in a 44 for the front, you can run a 30 right up until you go into Dana 60 territory unless you want to run the 44 on the lip of its limit until you get a 60. I'd just run the d30 with your 35s or even 36s then upgrade to a 60 when you go bigger(38s-40s type starting point)

Edit: I put "plenty strong for 30s" when i meant 35s, my bad

um an 8.8 is stronger then an xj 44, 31 spline shafts vs 30 is stronger, larger ring gear and carrier and same size pinion shaft as used on the ford 9s, larger and i think thicker axle tubes. weld the tubes to the diff and its got no weak point over the 44. yes the c clips are bad but theres c clip eliminators and personally i wouldnt drive with a broken shaft in there anyway.

1990heepxj said:

um an 8.8 is stronger then an xj 44, 31 spline shafts vs 30 is stronger, larger ring gear and carrier and same size pinion shaft as used on the ford 9s, larger and i think thicker axle tubes. weld the tubes to the diff and its got no weak point over the 44. yes the c clips are bad but theres c clip eliminators and personally i wouldnt drive with a broken shaft in there anyway.

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Yeah i ment the front 44 or does the waggy not have a front 44?? Sorry for all the questions kinda new here. I've decided to put my 8.8 in the rear now its just the front im worried about.

DoctorPhate said:

The HP30 is plenty strong for 30s if you run chromo shafts and truss it. Imo I see no point in a 44 for the front, you can run a 30 right up until you go into Dana 60 territory unless you want to run the 44 on the lip of its limit until you get a 60. I'd just run the d30 with your 35s or even 36s then upgrade to a 60 when you go bigger(38s-40s type starting point)

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yeah thats probably what i'll do. Anyone know of a good weld on truss for the 30?????? I have been lookin and haven't found to many options. I like the IRO 8.8 truss.but they dont make one for the 30

TMR Customs has a good truss system

Thanks for the help guys.now one mre question. I want to regear my diffs before i do the swap (gearing is different in the 30 and 8.8) all the ring and pinions i see are either for tj or are reverse cut?? What does reverse cut mean??? Do i need revrse cut gears???

you use reverse cut on a high pinion d30, the cut is just the direction the spiral of the pinion and the curve of the ring gear face. low pinion d30s technically use "standard cut" gears. also yes the waggy and grand waggy both come with 44s up front.

EDIT: i also want to edit myself on my first post, i said the 8.8 pinion shaft is the same size as the ford 9s, i was mistaken its the same size as a d60s

H wow the 8.8 is beefier then i thought.i will defenetly end up swapping the 8.8 in after i regear both d30 and 8.8 to matching ratios

If you're looking for something to increase the capability of the rig try this out.

http://staangsfab.com/products-1/jeep-cherokee-xj/ Rear coil conversion.

The 30 will be okay with 35's if it's open. I ran that on a TJ (which is low pinion) and never had problems. I was always scared to lock it though, but have known people who ran 35's on the locked 30 without problems.

And yes, you will need reverse cut gears for the high pinion 30.

I know a lot of people who have blown up 30s...

Some stuff:
Don't reuse the roll pin holding the cross shaft in. Buy a brand new one or tap for a bolt instead.
Don't lock it on 35s unless it's a full case locker, lunchbox locker = :explosion
What year is your d30 out of? If it's a 95 or later (or any year and has ABS), just install Spicer (no substitutes) 760X ujoints in the shafts. If it is 94 or older and does not have ABS, get shafts out of an XJ with ABS or any XJ made 95 or later, install 760X ujoints in them, and use those shafts.
Brace the LCA mounts, fully box the UCA mount on the passenger side, gusset the inner Cs if you feel like it, and maybe put mini skid plates on the undersides of the LCA mounts.

Ts a 92 i think i will keep it open fornow and when i decide to lock the front (i want an ox) then i'll upgrade to rcv's

DoctorPhate said:

If you're looking for something to increase the capability of the rig try this out.

http://staangsfab.com/products-1/jeep-cherokee-xj/ Rear coil conversion.

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I honestly dont have that kinda cash to put into rear suspension.i will prob stick with rear leafs. Or does anybody have a link to a good buildup for swapping in rear coils????? If i can build it for not to much i would probably go that route. Thanks again