PDA

View Full Version : Replacement of Font Diff on ZJ


Hunno
22-03-10, 06:15 PM
Starting to think about replacing the diffs, front 1st as the right hand side CV is & has been clicking since before the lake Lyell trip. Now I have got a relly bad shake coming from the left.
Steve T has suggested previously about changing to HP44's, which would allow me to run a bigger lift also.
My questions
1) What models are they on?
2) Is it a straight swap or do I have to change mounts or something?
sbadman
22-03-10, 06:34 PM
A HP30 out of an XJ is readily available and I believe a bolt in swap to a ZJ. You also get rid of the CV's in exchange for uni's, and near on the strength of a stock D44 (low pinion) due to the reverse rotation. I've heard plenty of stories of 35" rubber on even stock HP30's with no problems (as opposed to almost any D35, which will twist up like rope in the mere presence of a 35" tyre :D)
Steve F
22-03-10, 06:39 PM
Yep, I'd go with the D30 from an XJ to get the High pinion. The D30 can be built up pretty strong and will cope with 35's if driven with respect. Wooders had 36's on his and gave it hell at tuff truck (A few years ago now) and I think that was the slightly weaker low pinion TJ diff. I have a D44 I'll start building up after Easter for the rear of the XJ but I'll keep the D30 (regeared etc though) and I plan to run either 33's or 35's.

Cheers
Steve
Hunno
22-03-10, 07:55 PM
Ok so I can get a HP30 from an XJ. Will the gearing match to what I need? As for regearing that will have to wait as I need to clear a couple of bills first.
sbadman
22-03-10, 08:03 PM
Ok so I can get a HP30 from an XJ. Will the gearing match to what I need? As for regearing that will have to wait as I need to clear a couple of bills first.

Stock petrol XJ gearing is 3.55:1, I think ZJ may be lower though?
Steve F
22-03-10, 08:04 PM
I think the ZJ gearing is 3.73 and the XJ is typically 3.55 or 3.73 if you get one from a diesel, also look around for 3.73's on Ausjeep as a few have regeared and may have them lying around. Also do you have ABS, if you do then you'll need to swap the ZJ knuckles on to the XJ front end to keep it.

Cheers
Steve