• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

HP D30 strength

4x4JeePmaNthINg

NAXJA Forum User
Location
Colorado
I have an hp d30 27spline in the front and im looking for advice on what this axle can hold up to. Ive never run bigger than 32's and its an open diff.

I ask because i changed the diff fulid recently and i guess ive forgot how small (literal size of material) the ring gear is 3.73. It seems kinda scary for wheeling but maybe not?

If you guys have any pictures of what youve wheeled with this axle or set ups that are a good example of how far this axle will go strength wise i would appreciate it.



Thanks for all your help
 
All I can say is with a D30 up front, I got to the point where I could change a shaft on the trail in less than 15 minutes.
 
There is no correct answer for this question! The most important element is the driver/skills. A open diff can cause problems in itself. The 27 spline is the weakest variety!
 
I've broke axle u-joints on my D30, locked on 33's, on two separate occasions. I was a little stupid with the skinny peddle both times. Since then I've installed RCV axle shafts and have not had a problem since.

With the D30 and stock shafts, the shaft u-joints are the weak link. This is a good thing since they're easy to change and the ring/pinon aren't likely to be damaged.
 
If you plan to stay on 32's and open you will be fine.

It is dependent on if you are locked, wheel size, and foot size. In my humble opinion, locked on 33's with alloys is reliable. 35's is doable but risky.

FYI I have run 33's locked since 08 on alloy shafts. In that time I have broken one carrier which was my fault because the ring gear bolts came loose.
 
As said above, 33's with alloys is pretty safe. With 35's and alloys the weak link becomes the ring gear.

It really does come down to the size of your foot. I know guy who can break a d30 in 5 minutes on 31's, and I know guy who can run 37's for years without issues. Choose carefully which guy you want to be.
 
I know guy who can run 37's for years without issues. Choose carefully which guy you want to be.


Then that guy stepped up to 39" tires and still never had a problem lol


I think driver skill really plays an importance with this axle. Also gearing, as the deeper the gears the tinier the pinion and the more torque is given on the axle shafts. The guy mentioned above ran 37"-39" on stock 3.55 gears and never broke anything simply because of lack of gearing and being decently easy on it. I know others who ran 33" tires and 4.88 and broke ring and opinions by the handful.
Be easy on it and you will be fine, start getting the lead foot syndrome and you might be wanting to find a bigger axle
 
Im generally one to hit the break pedal if any wheels start spinning. It's time for a new line at that point. I have a 99 so I believe the shafts are 27 spline? What other variety other than 30 spline aftermarket is there?
 
there are 30 spline options for the HP30.

ARB makes a 30 spline locker.

Revolution Gear makes a shaft with the larger JK44 ujoints in both 27-30 spline.
although I don't reccomend the 27 spline version, then the inner shaft becomes the weak link.


I have an HP30 that has been locked on 35"s for the better part of 10 years now. its been over countless trails of all difficulty. in that time I have only ever broken on of the warn hubs.

the HP30 is actually a decent axle if you treat it properly. A good gear setup, A full case locker, Alloy Shafts, and Quality joints will help it last.

what others have said here also applies, wheeling smart is the key to making axles live. everything breaks if you abuse it. even 60s.
 
I have c8.25 rear so if I converted to manual hubs and alloys would I be no longer able to rotate tires and do the manual hubs space tires out further?

there is no reason to convert to manual hubs. they are not stronger or better.

I bought my axle built and the PO had done it. I would not spend the money on that.

but no, the hubs nor alloy shafts affect the wheels in any way.

the hub kit does space the tires out about 1".

regular alloy shafts attach to unit bearings just like the oem shafts. they are simply stronger.
 
So does anyone other than alloy make a unit hub that accepts the 30 spline inner/outer shaft combo?

Say i stuck with the inner and outer 27spline alloy shaft, is this a relatively strong combo? Ide rather the 30 spline obviously but a new carrier is a big expense.

Aside from the axles are the knuckles generally weak with 32-35s?
 
So does anyone other than alloy make a unit hub that accepts the 30 spline inner/outer shaft combo?

Say i stuck with the inner and outer 27spline alloy shaft, is this a relatively strong combo? Ide rather the 30 spline obviously but a new carrier is a big expense.

Aside from the axles are the knuckles generally weak with 32-35s?

several manufacturers make 30 spline inners.

if you are going to bother though the Revolution JK44 Ujoint shafts aren't any more expensive.

I don't think anyone besides alloy USA makes a 30 spline outer, but honestly I have never seen them be necessary. the break is almost always on the inner or the Ujoint.

if you're going to buy a locker and shafts anyways, you might as well buy what is the best stuff on the market. the cost difference between a 27 spline and 30 spline ARB is negligible. the price difference between various mfg is also negligible.

cases of Dana 30 knuckle breakage are rare and those that do it are wheeling at the most extreme levels.
I would worry more about the upper balljoint hole on the inner C than the outer knuckles.

there are hundreds, maybe thousands of Dana 30s under rigs on 33"-35" tires.
the amount of those that experience severe breakage are slim in comparison.
wheeling stresses components; shit breaks nobody can deny that. if you're going to build a 30, do it right and prepare for the occaisonal break.

if you want to run junkyard level stuff and don't want it to break, go to tons.
 
So does anyone other than alloy make a unit hub that accepts the 30 spline inner/outer shaft combo?

Say i stuck with the inner and outer 27spline alloy shaft, is this a relatively strong combo? Ide rather the 30 spline obviously but a new carrier is a big expense.

Aside from the axles are the knuckles generally weak with 32-35s?

My experience from above was with 27 spline shafts. If I were to do it all over again I would still stick with 27 spline shafts. I would much rather replace a broken shaft/u-joint that a ring and pinion on the trail. Plus if you are wheeling with other jeeps with 30's, it is probably more likely they will have a spare 27 spline than 30 spline shaft. In your case, 32's or 33's I would run 27 spline shafts without hesitation.

several manufacturers make 30 spline inners.

if you are going to bother though the Revolution JK44 Ujoint shafts aren't any more expensive.

I was looking into JK u-joints and the info is somewhat unclear. From what I read the JK u-joints are the same diameter as a 30/44 cap (1.188) but the j-joint itself is slightly longer. Therefore is the joint any stronger if the caps are the same size?
 
I was looking into JK u-joints and the info is somewhat unclear. From what I read the JK u-joints are the same diameter as a 30/44 cap (1.188) but the j-joint itself is slightly longer. Therefore is the joint any stronger if the caps are the same size?

the JK 30 uses the same size u joint as the XJ 30, a 1310 cross.

the JK 44 uses a 1350 size cross instead.

consider this:

many JK rubicon guys are successfully running 37" tires on a rig that is much heavier than any of our XJs. the D30 760x would never hold up on a scale that wide.
 
the JK 30 uses the same size u joint as the XJ 30, a 1310 cross.

the JK 44 uses a 1350 size cross instead.

consider this:

many JK rubicon guys are successfully running 37" tires on a rig that is much heavier than any of our XJs. the D30 760x would never hold up on a scale that wide.

True, not going to argue those points. But here is the confusing point where I got my information:

http://www.4wheelparts.com/Drivetra...s=237&t_pt=101013&Manufacturer_PQ=Dana+Spicer

It shows the same cap diameter for the 30/44 u-joint and the JK 44. The JK 44 is an inside snap ring 1350 joint, and the I looked up a strictly 1350 u-joint and it lists it cap as 1.188, the same diameter as the xj 30 j-joint.
 
the overall size of the cross on the 5177x is larger.

If I could get at my 760x spares I could show you a side by side comparison.

the caps are the same diameter OD, but the larger cross means more material, which adds strength.
 
does this mean they (5177) can be used instead of the stock 1310?

1310 is the driveshaft joint.

760x is stock XJ axleshaft ujoint.

you can only run 5177x joints in an XJ if you have the shafts to accept them.
currently only Revolution Gear and Axle makes them.
 
Back
Top