ZJ weak points

[1BadZJ]

I am slowly a building up 93 ZJ with a V-8. I have done the motor and rebuilt the tranny. I just want some opinions on some possible weak points that I would need to replace or strengthen. I know I need to replace the rear axle and I heard the t-case might be a weak point to consider. If any ZJ owners have done some cool upgrades some ideas would welcomed also. I already have the suspension picked out, so no need for help in that area. Any input or help would be grateful

 

[Cody]

I found the roof to be pretty weak

Cody

 

[1BadZJ]

roof

Roofs are way over rated, especially when it rains or snows. I am not quite ready to turn a my zj build into a buggy build. If I roll it some day then I might have to do the same as you did, if I get far enough(money) into the build.

 

[utahxjer]

Well while lifting my bud's ZJ this weekend, we see he has a low pinion D30, so you might wanna swap out to a HP if you have the same problem.

 

[Herzog]

I found the roof to be pretty weak

Cody

 

[Cody]

What size tire? What are your goals (i.e. what kind of trails do you plan on traveling upon?)

The 249 that your jeep came with is a POS. A good swap is a 231 or a 242 t-cace, or if you sell drugs an atlas makes an even better swap. the pre 96 249 t-case does not have a locking center diff, which means you don't really have 4-lo in the truest sense. This is all assuming you weren't one of the lucky few who acquired a v8 ZJ w/o all wheel drive.

The front 30 isn't that bad of an axle and will handle up to a 33" tire just fine. If you gear start to gear it lower (like 4.10 or numerically higher) then the hp 30 is a cheap upgrade, otherwise the ONLY step from there is to go to a 60. The rear 35 is a turd, but can handle 33's if you talk sweet to it nightly. 8.8, 9", 44, 60, toy 8", are all good swaps to get rid of the turdy5.

anywho, hth

Cody

 

[4x4phil]

If your jeep has the front cv joint you might want to swap that out for a ujoint type axle shaft. The front drive shaft on the one i've owned and the ones I've worked on have a cv type yoke and joint at the front axle and those can't handle much lift. The low pinion 30 doesn't help either. Mine had vibes at 3.5 inches. You can replace the axles and the lower driveshaft and yoke, or you can do it cheaper and easier by buying a used xj, tj axle. It's a direct swap. Make sure you get the front driveshaft or take in your old one and have it converted. Just make sure you don't get the disconnecting axle and try to find one that has the 297X joints. And of corse the ratio's need to match but you should be able to get a high pinion 30 for around $200 or cheaper. It's definately easier to find one from an xj. All xj's had hi pinion 30's.

 

[4x4phil]

By the way Cody has the coolest zj (what's left of it) I've ever seen so he's a good person to listen to. He seems to be the zj guru of rme.

 

[1BadZJ]

tires, axles

I plan on running at least a 35" tire and may stuff up to a 37". I want a real trail rig and I am not afraid to cut. I might have a Ford 9" for the rear, do you thing that a super or awesome 30 kit for the front would hold up. I am not easy on the skinny peddle. I want to make it as strong as possible but just don’t have much funds right now.

 

[95jeepgrndchke]

I plan on running at least a 35" tire and may stuff up to a 37". I want a real trail rig and I am not afraid to cut. I might have a Ford 9" for the rear, do you thing that a super or awesome 30 kit for the front would hold up. I am not easy on the skinny peddle. I want to make it as strong as possible but just don’t have much funds right now.

Any reasons your going with a 9" over other axles? not flaming just curious?

 

[Cody]

do you thing that a super or awesome 30 kit for the front would hold up. I am not easy on the skinny peddle. QUOTE]

Nope. A HP 30 will last for a bit w/ 35's but if you're hard on it, it's going to break. Same for a front 44. If you're going to be hard on it and want to joint the 37" club, then you will need a 60. Kevin (kevins jeep parts kevin) runs 37's on an open hp30 and hasn't broken too much but he's pretty nice to it.. If you lock it and hammer it it's going to go boom.

Any reasons your going with a 9" over other axles?

3rd pinion support, stock 31 spline shafts, good width, 3rd member, rediculous amount of aftermarket support thanks to drag racers.

and I haven't been able to break it!

 

[1BadZJ]

60 vs 9

"Any reasons your going with a 9" over other axles? not flaming just curious?"

I would have gone with a dana 60 just for the strength and cost, but I might be getting a Ford 9" for free from a friend. My understanding is that it is stronger than a 44 but not as strong as a D60, but has more clearance than a dana 60. They are also lighter and easy to convert to disc brakes.

 

[1BadZJ]

what do you run

Cody "3rd pinion support, stock 31 spline shafts, good width, 3rd member, rediculous amount of aftermarket support thanks to drag racers.

and I haven't been able to break it!"

So what are you running for axles on yours?

 

[N-Smooth]

you might want to run a different rig(frame) or a buggy if you are super serious. unless of course you don't mind slowly "buggifying" your rig when you could do it right the first time. just making sure you see all your options

p.s cody has a 9" and a hp 44 that he just recently polished

 

[mbryson]

I plan on running at least a 35" tire and may stuff up to a 37". I want a real trail rig and I am not afraid to cut. I might have a Ford 9" for the rear, do you thing that a super or awesome 30 kit for the front would hold up. I am not easy on the skinny peddle. I want to make it as strong as possible but just don’t have much funds right now.

Let's see....

35" tire (going to a 37")

....Super 30 kit....

"I am not easy on the skinny pedal".......D44 is not enough, don't even bother with the 30. Either learn to live with a 'light' throttle foot and run the 297 joints (available in the D30 {don't think you can 'baja' that D30--Housings bend pretty easily at speed} or D44), or buck up for a 60 that'll save you money in the long run.

 

[1BadZJ]

plan

you might want to run a different rig(frame) or a buggy if you are super serious. unless of course you don't mind slowly "buggifying" your rig when you could do it right the first time. just making sure you see all your options

My plan is to build the ZJ up as much as I can with out going over board, but make it a tough trail rig. Then when I am happy with it I can beat on it while I slowly build up a real buggy. Now this will be some time down the road when I have some money and time. The ZJ will be my first step my entry-level rig into rock crawling and someday I will step up with the big boys.

 

[1BadZJ]

axles

Cody what axles are you running on your ZJ/buggy?

 

[Cody]

Sounds just like me 4 years ago--oops.

I would say the best compromise of money and offroad performance would be a 5-6" long arm lift, 35's, front 30 w/ ujointed shafts, rear 44/8.8/9, 231 t-case and lockers.

As long as you remember you are driving a 5500 lb sherman trail tank, you should be able to make it live. Once you go bigger than 35's and you're hard on it, there is really no cheap way of making it work reliably. You're talking 60's or super spendy alloys in a 44 which is a bad idea anyways.

My 9" is stock except for the disks. I pulled the shafts out last week and the splines aren't twisted so I'm pretty impressed with the 9" strength.

I don't think a rear 60 is any stronger than a 9". It has a higher pinion which is nice, but the ring gear on the 9" is thicker and the shafts are about the same. You can take a 9", put a 35 spline spool, nodular 3rd, and 35 spline shafts and you'd have a light weight, fairly high clearance almost bomb proof rear axle.


Cody

 

[N-Smooth]

As long as you remember you are driving a 5500 lb sherman trail tank, you should be able to make it live.

thats what i was thinking

 

[1BadZJ]

front axle

Sounds just like me 4 years ago--oops.

I would say the best compromise of money and offroad performance would be a 5-6" long arm lift, 35's, front 30 w/ ujointed shafts, rear 44/8.8/9, 231 t-case and lockers.

As long as you remember you are driving a 5500 lb sherman trail tank, you should be able to make it live. Once you go bigger than 35's and you're hard on it, there is really no cheap way of making it work reliably. You're talking 60's or super spendy alloys in a 44 which is a bad idea anyways.

My 9" is stock except for the disks. I pulled the shafts out last week and the splines aren't twisted so I'm pretty impressed with the 9" strength.

I don't think a rear 60 is any stronger than a 9". It has a higher pinion which is nice, but the ring gear on the 9" is thicker and the shafts are about the same. You can take a 9", put a 35 spline spool, nodular 3rd, and 35 spline shafts and you'd have a light weight, fairly high clearance almost bomb proof rear axle.

What are you running for a front axle?

Thanks for the input, directions and inputs help.