dana lp 30 and hp30

i have a 00xj with dana 30low pionion and want to put in a high pioion 30..only reason is that i have a arb locker and want to keep it... i know the diff will fit but are confused on the hp30 diff if all the parts are interchangable execpt for the gears... should i get a disconnect or non disconnect planning for 5" to 8" lift

install in your low pinion unless you are lifting jeep above 5"

you want the non-disco, unless you want to use 2 lo. If you get a disco, you will need a cable to engage the front axle...or alot of vaccum lines.

Sponge Bob said:

install in your low pinion unless you are lifting jeep above 5"

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Why is that?

You will have to replace your gearset and bearings but your locker will work just fine.

You can find complete, non-disco front ends for around $75 if you search long enough.

The one in my jeep was free, if you don't count the gas money to go get it.

Ditto,the carrier is the same.

lowrange2 said:

Why is that?

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Jeep went to the LP30 after they upgraded the XJ in 2000 because of clearence issues with headers & other things.
The previous poster was correct in stating that you need around 5" of lift to clear a HP30 on a late model XJ.

Edited to fix year of change to LP30.

they went to the LP30 in 2000

never heard of an issue with clearing the exhaust swapping an HP30 into a 2000 or 2001....but i guess its possible.

is there a downside to the disco front end other than needing vacuum or a cable?

is it noticeably weaker or anything like that?

i kind of like the fact that it can be dis engaged like hubs

better gas mileage

There are 297 shafts for the disco housing, but they aren't common. I know they came in 95 YJs....not sure if that's the only application or not though.

Another downside to the disco is that it's one more piece that can fail. If you have the cable, then that helps. The housing is actually a little stronger with the disco, but since it's hard to get the same 297 shafts for the disco, they're commonly swapped out, or converted to running on piece shafts.

The whole reason for lockout hubs, and the disco front axles is the increase in gas mileage. When you're talking big trucks, it can made a difference, however, in terms of a small vehicle like an XJ, they determined that the difference was negligible, so they ditch the disco feature. Plus, again, less to break!

Some people like the ability to disengage, like lockouts, and if you want that, then find some 297 shafts for that thing and run it!! You can ditch the vacuum stuff and use a cable, or just operate it manually (which you'd have to crawl under there, but not that big of a deal).

i had it rigged on my 85 to where i had to pop the hood and switch a vacuum line. but i figured it wasnt any worse than getting out and engaging hubs


so the non disco front ends use the 297 shafts?

wingnutooa said:

i had it rigged on my 85 to where i had to pop the hood and switch a vacuum line. but i figured it wasnt any worse than getting out and engaging hubs


so the non disco front ends use the 297 shafts?

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Not all of them, the later ones do though. For XJs, the switch over is roughly 96. 97+ should definitely all be 297. My 96 should have had 260s, but it had 297s, it's a jeep thing!

AFAIK, no XJs with disco D30s came with 297s. I'm not saying it's not possible, but I don't think it was supposed to be an option. They stopped using disco D30s all together in the 91ish range (give or take a year or so, again, the jeep thing).

The only application that I'm positive has disco shafts with 297 joints is a 95 YJ.


If you convert it to one piece shafts, you can grab spare shafts out of not only XJs, but ZJs and TJs too!! TJs are all 297, and I'm not sure on ZJs, but they should be 297s too. ZJ/TJ never had disco D30s.

the 95 yj needed to have abs for the 297 joints same as the cherokee