HP D30 vs. D30

TheRedZJ

TheRedZJ

Member
Joined
Feb 25, 2011
Location
Ayden, NC
Whats the different other then just having more ground clearence for rocks? i know alot of the cherokee have them stock and was going to get a HP D30 out of one and put it in my 95 Zj, is there anything special i have to do to swap the HP D30 in?
 
Reverse rotation gears are stronger because they run on the drive side of the gear, rather than the coast side.
 
A HP30 axle from an XJ would be your best bet... it would have the link mounts on it already. Not sure if they are a direct swap or not, but I'm sure there isn't too much involved with it. Maybe somebody with a ZJ can chime in about it. If you run TJ axle shafts in it, it will have the 297x u-joint, versus the 260x that the XJ probably would have (bigger u-joint).
 
A HP30 from an XJ will be a direct bolt-in to a ZJ
 
I just put an HP 30 in my TJ the ground clearance thing is a little deceiving. Your drive shaft will be about 4" higher however the bottom of the differential is the same height from the ground as a low pinion.

About the only advantage I see to HP is that in theory it is stronger then a low pinion because as other people have said it it runs on the drive side of the gear tooth.
 
jds97Wrangler said:
About the only advantage I see to HP is that in theory it is stronger then a low pinion because as other people have said it it runs on the drive side of the gear tooth.
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It's not just a theory and having the d-shaft that much higher is a huge advantage. I've seen quite a few front shafts get a nice dent in them and subsequently twist into two pieces. Unless you carry spare front driveshafts with you, it can potentially save your weekend wheeling trip. You don't have to wheel balls to the wall to slip off a rock and damage the driveshaft. My .02.
 
willness33 said:
It's not just a theory and having the d-shaft that much higher is a huge advantage. I've seen quite a few front shafts get a nice dent in them and subsequently twist into two pieces. Unless you carry spare front driveshafts with you, it can potentially save your weekend wheeling trip. You don't have to wheel balls to the wall to slip off a rock and damage the driveshaft. My .02.
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I didn't mean anything by my theory comment. Yes running on the drive side is stronger it is not theory it is engineering fact. As for the ground clearance yes having the drive shaft up 4" inches is nice and has its advantages. But you do not gain differential ground clearance with the HP that was the only point I was making.
 
jds97Wrangler said:
I didn't mean anything by my theory comment. Yes running on the drive side is stronger it is not theory it is engineering fact. As for the ground clearance yes having the drive shaft up 4" inches is nice and has its advantages. But you do not gain differential ground clearance with the HP that was the only point I was making
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uhh.....duh.... :shaking:
 
Metto said:
uhh.....duh.... :shaking:
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I guess we should all have the great wisdom of Metto! :flipoff2:

But when I was researching putting an HP in my TJ I found a lot of people who hadn't installed a HP before and thought it would give them more ground clearance. SO I was just sharing some information to someone thinking about doing the HP install.
 
Food for thought: The HP is stronger when you are driving forward, and more weight is transferred to the rear of the vehicle. The LP is stronger when you are backing up, and more weight is transferred to the front of the vehicle.

Since we are all typically trying to go forward over obstacles, the advantages of an HP axle are usually in play. But when you are in a tight jam and trying to back out, keep that in mind. The reality is that you don't see LP axles blow out ring gears all the time going forward either.
 
well i dont plan on doing that much hard wheellin. but i see that over all it looks like the HP D30 is the stronger axle and is worth tryin to get one
 
TheRedZJ said:
well i dont plan on doing that much hard wheellin. but i see that over all it looks like the HP D30 is the stronger axle and is worth tryin to get one
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IMO it's worth it if you're planning on a regear anyways or can find one already geared to what you want or have. However, I don't think it's worth it if you're already running the gearing you want and the LP30 is still working.
 
that would be the plan man but im on a high schooler budget and i aitn gota job. im tryin to find the HP D30 for cheap so i can run them for a awhile till i have money for 4.10s and possibly a 8.8. thats the plan atleast.haha
 
jeepinmatt said:
Food for thought: The HP is stronger when you are driving forward, and more weight is transferred to the rear of the vehicle. The LP is stronger when you are backing up, and more weight is transferred to the front of the vehicle.

Since we are all typically trying to go forward over obstacles, the advantages of an HP axle are usually in play. But when you are in a tight jam and trying to back out, keep that in mind. The reality is that you don't see LP axles blow out ring gears all the time going forward either.
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This is a good point, but 9 times out of 10, you're gonna be a little rowdier going forward, and be more careful backing up. Having the front bound up in reverse is something that sucks either way, LP or HP. If you're gonna wheel a 30 hard, especially in a ZJ that weighs a lot, you might have to do a little bit more preventative work on the axle than a HP housing.
 
i dont plan on gettin that big of tires maybe 33s at the most but thatll be in the future because i only have 2inch spacer lift on 31s. but when yall say be more careful backing up or whatever you mean in fourwheel drive right?
 
yes.
 
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