(Q) Bolt in front axle replacement.

So the differential went, not sure where it went, but its gone.
I dont even really care at this point because the bearings are on their way, and the ball joints are long gone.
Its a 2000 xj with a np242, 3' springs on 31s that has been plowing snow for 7 years.
Im going to go and pull a complete axle with hubs at a junkyard for $240 or so. The way they prices things, it dosnt matter where the part comes from, an axle is an axle($140), and a hub is a hub($37).

So to the questions.

What are my options for direct bolt in installation?
Will a TJ d44 really just bolt right in? (not holding my breath on this one)
Can i pull wagy locking hubs and slap them on a d30 (not 35), or the tj d44? (i know they have a couple wagoneers sitting around)



Whats all this vacuum disco business?
Did a bit of reading on this but please correct me if im wrong.
The vac disco was used on pre 92s with 231s. Which is a part time only tcase. So the only point of the vac disco is so your front shaft dosnt spin when youre in 2wd?
So is there any kind of mechanism to prevent the driveshaft from spinning on my 2000(the 242 was swapped in), it always spins.

A rubicon TJ 44 would bolt in but good luck finding one and it would be 4:10 gears..

Waggy hubs wont work on any of it...and a D35 is a rear axle....

You don't want a disco axle...

So you want to look for a HP Dana 30 Non disco with the larger u joints and sure if they got rubby 44s for 240 get as many as they have...

are there other possible donors that will be better than an xj(they sure have plenty of xjs), if i do find a tj d44, will the rear axle be a bolt in replacement as well?, how would 4.10 gears effect my MPGs running 31s?

How can i tell its its a d35 hp or lp. This is what i have right now, which one is it?

Is there a simple way to make the images appear smaller?



And Im guessing this is a 8.25 rear

Are you looking for front and rear axles?

Whitout fabrication nothing else will "bolt in".

To post pictures you have to host them on a site like photobucket and link it here.

are the pictures not showing up?
Im just looking to replace the front, but if i find a d44 ill need to match the ratio in the rear. And a matching axle for $150 seems like the best option.

Also, just thinking, different gears front and back in full time 4wd shouldnt actually cause any harm, just power distribution will be uneven, right?

Looks like the current one is LP


Maybe this would not have happened with an hp

Is there a reason you want to upgrade to a D44? A stock D30 is pretty strong and there are a lot of upgrades out there if you want to beef it up in the future. Unless you're planning on running 35's or larger (or maybe wheeling it really hard on 33's), I'd just stick with the Dana 30.

Any XJ D30 will bolt right in so finding a good replacement should not be difficult... The most important thing is to make sure it matches your existing rear axle gearing. The gear ratios MUST match if you want to use your 4wd. If you were to try to drive in 4wd with axles with two different ratios your rig would not move at best, and you'd break drivetrain parts at worst, so yes, you DO need to make sure you match gear ratios! Most 4.0L automatic XJ's have 3.55 gears, but it'd be smart to verify what's in your axles now as well as in any replacement axles you look at.

The non-disconnect axles are considered a little bit more desirable, and since that's what you've got in there now, that's what I'd look for to replace it with. You could run a disconnect axle, but you'd probably want to do the mod to lock the passenger side axle shaft together since you don't have the vacuum disconnect setup in your XJ. Someone correct me if I'm wrong, but from what I've read there is little benefit to keeping the disconnect system. Apparently it was supposed to help with MPG (due to having less parasitic loss from the driveshaft spinning), but in the real world the difference is pretty much nil.

'01 model year XJ's and possibly your '00 came with a Low Pinion axle. These have less ground clearance, steeper pinion angles on the driveshaft (which can become a problem when lifted over a certain height), and are said to be not quite as strong than the High Pinion version of the D30. If you're not planning to lift your rig any more than you're at now you're probably fine with a LP30, but if it were me I'd look for a High Pinion version. You're more likely to find a HP30 anyway since they're much more common.

There are differences in the size of the u-joints used depending on model year and whether or not the rig came with ABS brakes, I can't recall the exact cutoff year, but basically newer XJ's and older ones with ABS have the larger, stronger u-joints. This may not be a concern to you if you don't wheel very much, or you can always swap in axle shafts with the bigger joints later on (what I'm planning to do), so I wouldn't consider the small joints a dealbreaker on an otherwise good axle, but just FYI.

There were also some differences in the hubs (aka unit bearings) used over the years. I believe that '84-'90, '91-'99, and '99+ all use a different hub, and I believe they use different brake rotors to match as well. I don't know if the rotors off your '00 will fit older model hubs or not, but it's something to be aware of if the used axles you're finding are mostly pre-'99. If they don't fit, you may have to do some parts swapping to get a hub & rotor combo that will work together. Maybe someone else can chime in on that.

The reason for the 44 is if i found one, it would be the same price as the d30, so why not.
The reason im just pulling the whole set up from a junk yard is because everything is broken on mine. Everything being gears, ball joints, hubs/bearings. Just seems better to swap the whole thing.

So to wrap things up if a magically find a tj d44, everything will just bolt into place including driveshaft, steering,etc... but i will need to deal with the rear to match... but ill be ready for bigger tires.

More realistically i will pull a hpd30 ,no disco, from a 93-99 xj, and get it complete with hubs/brakes and make sure its 3.55.

I can see enough from your picture of the rear axle that you have a LP D30. Been there, done that. Get the HP D30 and rock it until it breaks.

If I was going to swap I'd put a Grand Cherokee D30 to get the big brakes. I've only done a little research and don't know the details or exactly which year is the best. Maybe somebody else can help out with the info.

HappySlappy said:

If I was going to swap I'd put a Grand Cherokee D30 to get the big brakes. I've only done a little research and don't know the details or exactly which year is the best. Maybe somebody else can help out with the info.

Click to expand...

Might want to research that a little more...

The WJs have the "bigger" brakes and are also:

Low pinion
Run CV joints
and the axle is somthing like 6 inches or so wider, so it wouldnt bolt in

Now swapping the WJ knuckles and brakes onto the XJ dana 30 is popular but is not just a bolt on.

whitexj98 said:

Might want to research that a little more...

The WJs have the "bigger" brakes and are also:

Low pinion
Run CV joints
and the axle is somthing like 6 inches or so wider, so it wouldnt bolt in

Now swapping the WJ knuckles and brakes onto the XJ dana 30 is popular but is not just a bolt on.

Click to expand...

Damn it. I knew it was too good to be true. Thanks for setting me straight.

ok, got a 99 (hight pinion from what i can tell) for $200, this thing is in FAR better condition that what i have.
It was prepulled too.

I will take into consideration all advice as to what i should do while swapping this out. All i have left is the 4 control arm bolts. Was working with no lube, so didnt even want to touch those. Either way im sure they are not going to cooperate considering 2 out of every 3 bolts i touched broke. I will be soaking them with pb whenever i step out for a smoke this evening. Working with all hand tools here.

Another thing: from my understanding with these differentials, i should be able to turn one of 3 parts(left hub, right hub, output to driveshaft) and one other one should turn freely. I am slightly worried about the new axle. Will check it out some more in a bit here.

Should there be any play in the output of the axle?

Thats a HP but it's not a 99.

Yes, if you turn one of the axle shafts the pinion or the other shaft should turn.

this video clears it up a bit.
http://www.youtube.com/watch?v=K4JhruinbWc

is fluid leaking from the pinion normal without a driveshaft connected?
seems as though the pinion shout turn if i turn both wheels in the same direction, right?
was the vacuum disco in place to prevent the driveshaft from turning when in 2wd?

thanks for all the info everyone.

DimaXJ said:

this video clears it up a bit.
http://www.youtube.com/watch?v=K4JhruinbWc

is fluid leaking from the pinion normal without a driveshaft connected?
seems as though the pinion shout turn if i turn both wheels in the same direction, right?
was the vacuum disco in place to prevent the driveshaft from turning when in 2wd?

thanks for all the info everyone.

Click to expand...

Wait, it's vacuum disconnect?

Yes, fluid is going to leak from the pinion when there's no yoke installed.

i was just wondering about the vacuum disco, i dont think it is, how do i tell.

Why do you say its not a 99 lowrange2

DimaXJ said:

i was just wondering about the vacuum disco, i dont think it is, how do i tell.

Why do you say its not a 99 lowrange2

Click to expand...

Lapse in knowledge. You're right. It probably is a 99. I was thinking 99-01 was low pinion but they went to low pinion in 2000.

Vacuum disconnect has a big mechanism on the passenger side axle tube. Yours won't be.

Lowrange2 said:

Lapse in knowledge. You're right. It probably is a 99. I was thinking 99-01 was low pinion but they went to low pinion in 2000.

Vacuum disconnect has a big mechanism on the passenger side axle tube. Yours won't be.

Click to expand...

Ive heard of some late build 99s with the LP axle.

I'm about in the same boat with mine. Bad pinion bearing and bad ball joints

Lowrange2 said:

Lapse in knowledge. You're right. It probably is a 99. I was thinking 99-01 was low pinion but they went to low pinion in 2000.

Vacuum disconnect has a big mechanism on the passenger side axle tube. Yours won't be.

Click to expand...

thats what i thought.

There appears to be a problem, same problem in both axles, maybe someone can explain it.

The Original axle.
Somehow I lost the big nut that connects the driveshaft to the pinion(this is how this venture began).
After that, when i got in reverse, the differential locks up, and if i gas it, it feels like im running over bricks and sounds like someones banging a hammer on something. Further testing with the car lifted up: if a helper spins passanger wheel forward, i can spin the driver wheel in any direction. If the passanger wheel is spun in reverse, the driver wheel will only go forward(if i hold the driver wheel in place, the helper is not able to spin the passanger wheel in reverse).

"new" axle.(not yet installed, just turning hubs)
same thing but opposite(perhaps because hp is an up side down lp)
spinning one wheel in reverse, the other wheel can do whatever.
Spinning one wheel forward, the other wheel has to go in the opposite direction.

Any and all input is greatly appreciated.

Started typing this before the above response, is that the problem?

The other axle will spin in the opposite direction. That's how spider gears act.

The pinion nut holds the pinion in place... You must have it on there or the pinion will drop down in to the ring gear and make a mess.