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Looking for criticism of my build plan

krieg80

NAXJA Forum User
Location
Virginia
Hey guys, I'm hoping someone with knowledge could give me a quick critique of my build plan. Here's what I've got so far:

'90, 4.0, AX-15
Zone Offroad 3" lift w/ nitrogen shocks
IRO double shear track bar
31" Goodyear Wrangler Duratracs mounted on 15x7's
Dynomax exhaust

Bone stock other than the above-mentioned. It's proven to be an excellent daily driver with zero post-lift driveline issues and it handles the Greens and mild Blues at Rausch Creek like a beast. In any case, I'd like to be able to run the more difficult trails, so here is what I've come up with in order to do so (the goal being to clear 35's without going any higher):

Axles:

-I'd like to stick with the HP D30 up front in order to keep costs down. It's a vacuum-disconnect model, so I plan to do the one-piece conversion first then beef it up a bit with chromoly shafts/760x U-joints and a diff cover.
-D35→D44 swap in the rear, preferably a D44 out of an older XJ for convenience.
-4.88 gears
-Aussie or Spartan locker in the front (undecided)/selectable locker in the rear (leaning towards OX)

Wheels/tires:

-35" Goodyear MTR's on 15x8 steel beadlocks. I want to stay at 3" of lift so there will be lots of fender trimming and bumpstopping.

Extras:

-JKS quick disconnects
-HD Offroad no-lift shackle relocation brackets with IRO adjustable shackles (should net an extra .5-.75 inches of lift). My stock shackles are at a 90-degree angle right now.
-2x6 steel rocker replacement

That's it in a nutshell. I think my plan would give me a very capable yet affordable XJ that could do pretty much anything I wanted it to within reason. I'm curious to know what you guys might do differently. Thanks!
 
35's on a D30 is asking for trouble. You will have to cut the hell out of it to clear.
 
Frame stiffeners, bumper to bumper. Steering box replacement spacer and frame bracing. Do it before everything tears itself apart.

David Bricker / SYR
 
33's and lockers will handle damn near anything for a full bodied XJ at Rausch. I did blacks and some reds on 31's/opens, bellypan did its jobs for sure. Bigger tires and you're gunna want bigger brakes too, look into the WJ swap.
 
Thanks for the responses. I'll get a steering spacer and a full set of frame stiffeners and install those first before I do anything else.
 
Frame stiffeners, bumper to bumper. Steering box replacement spacer and frame bracing. Do it before everything tears itself apart.

David Bricker / SYR

Great advise from David. Otherwise it's like starting a home construction on a mud foundation.

Welcome aboard. The second good upgrade is always a NAXJA membership.
:)

... and introduce yourself to your local chapter. It's a great club/organization.
 
yep. from a guy who almost pulled his steering gear off the frame rail last trip out: frame stiffeners and steering gear reinforced
 
You should also consider the Chrysler 8.25 rear axle out of an XJ if you have trouble finding a D44. As long as its the 29 spline its comparable to the D44. Might be able to find one easier too.
 
You should also consider the Chrysler 8.25 rear axle out of an XJ if you have trouble finding a D44. As long as its the 29 spline its comparable to the D44. Might be able to find one easier too.

It will definitely be cheaper
 
You should also consider the Chrysler 8.25 rear axle out of an XJ if you have trouble finding a D44. As long as its the 29 spline its comparable to the D44. Might be able to find one easier too.

The only thing that concerns me about the 8.25 is the C-clip design. I was a passenger in a Suburban once that had a C-clip let go at 65mph on the highway. At first I thought we blew a tire until we pulled over and I saw the wheel stuck out about a foot! When I popped the diff cover it looked like a bomb had gone off inside; the spider gears were completely shredded.

The 29-spline 8.25 is closer in strength to the D44 than I thought, though. Here's a comparison I found:

Spline count/Shaft diameter at splines/Shaft diameter at neck down/Tube diameter/Ring gear

Dana 44: 30-spline/1.281"/1.234"/2.75"/8.5
C8.25: 29-spline/1.250"/1.141"/3.00"/8.25
 
I was worried about the c clip design as well, but never read any stories of them braking.
 
Do not remember the exact year for the changeover, but your D35 could be c-clip as well. Do not let that aspect bother you. Putting some discs on the rear would help that also.
A D44 shaft/bearings etc can fail. Look at the later part of the team naxja build.
My 29-spline C8.25 has been trouble free going on 5 years now.
 
33's and lockers will handle damn near anything for a full bodied XJ at Rausch. I did blacks and some reds on 31's/opens, bellypan did its jobs for sure. Bigger tires and you're gunna want bigger brakes too, look into the WJ swap.

Yup.

XJs are best at home on 33s IMHO. 35s are asking for a lot in upgrades to keep them in one part... both the body and the drivetrain. I've been out of the XJ game for a while, but you should save money on going bigger and spend it right. Get some good 3" leafs and a .75" shackle, your 3" coils are probably fine. Get some Fox shocks or Bilstein 5165s or whatever they're pushing now. Armor up, throw some stiffeners on, throw an aussie in the front with freshened up D30 parts (new 760x ujoints, ball joints, hubs, whatever you need) and if you're feeling frisky do the WJ swaps. You don't need to, but should get some sort of steering upgrade. Selectable in the rear; gear accordingly.
 
Any one that wants to put 4.88 gears In A 8.25 should know that Un less you buy a aftermarket carrier you will either have to grind the center pin or the ring gear. Neither of witch is a good idea in my book.
 
Any one that wants to put 4.88 gears In A 8.25 should know that Un less you buy a aftermarket carrier you will either have to grind the center pin or the ring gear. Neither of witch is a good idea in my book.


That's only if you plan to add a lunchbox later on, if you did locker and gears together you can add the locker and pin then add the ring gear. Hence why many do those two upgrades together
 
With a c clip axle correct me if I am wrong but don't you have to pull the pin to get the axles to move in far enough to get the clips off? Hence the the need to grind the pin or the ring gear.
 
A bit of two ring gear teeth need to be ground even to fit 4.56 on the 8 1/4. Full case locker or not.

David Bricker / SYR
 
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