Front diff swap D30 to ?

[curtis]

A 44 has the same axle joints.

[aw12345]

Like I said before, other than better gearing choices not much gain between a D30 HP and a D44 of any variety. Other than that the latter costs a lot more.

[brokenujoint]

I'll tell you what I DO know.. Don't leave a hot soldering gun on the ground while sitting next to it, they try to stand up by putting your hand on the ground... ON THE SOLDERING IRON . Not only will your neighbors think you have tourette's syndrome but you'll be so mad at yourself you'll wanna punch yourself in the face...

[aw12345]

Yup hot stuff smarts when you rest your hand on it. You ought to try some good welding loogies in your shoe sometime, those are fun too

[Elusive]

Like I said before, other than better gearing choices not much gain between a D30 HP and a D44 of any variety. Other than that the latter costs a lot more.

not true.
the dana 30 differentials are very small. Even ARB's will break with 37's on a dana 30. The cross pin is made out of 300m but I have seen 2 of them shatter in dana 30's. The detroits and lockrites suffer the same problem.
When the diff in a 30 breaks it will most likely require new gears (if the gears themselves didnt break). If a 44 breaks you are much more likely to just replace a shaft of U joint.

[aw12345]

As far as a D30 locker disintegrating when the gears go, could happen, but not a sure thing. One of my buds twisted a front shaft destroyed 3 gear sets and the Detroit is still alive. Granted a few of the small bolts on it went awhol. Which was an easy fix. About the only big advantage of an old HP D44 other than better gearing choice is the ability to run Hi steer arms. Getting the steering away from rocks is a good thing. Running 37's on a D30 is living on borrowed time unless you are extremely lucky and pussyfoot around and over rocks.

[curtis]

The post is about going to 40" tires some day. A 44 is only good to to 37" tires not 40's. I have broken three gear sets and three axles in a 30 with a Detroit. And the Detroit is still going. All breakage was do to driver having to much fun with life time warranty.lol

[ROBERTK]

Daym, this thread is ALL over the place. And with some info that is not true or at least misleading.
A few things I saw that seem wrong, or came across wrong. In no particular order.

JKD44 front ujoints ARE larger then any other D44 or D30 front ujoints up till 2013. At which time now the JKD30 comes with new larger JKD44 front ujoints. They are basically the same width cross as a D60 with D44/30 caps. Huge improvement over 760's. Does this apply here in this thread, No. But I saw reference to all the same including the JKD44.

Then there's talk of a HP9 now and convert over to some D60 outers later. This seems wrong as its typed. A hp9 by currie is not reuseable if over about a 35" tire. so the only reusable part is the housing which is going to be narrowed when inners are cut off to weld on D60 inners. Unless you're talking TrueHi9. Then if you ahve the thousands for that center section, why not just do it right and get a True complete axle.

As for a RJD60 rear and a 9" (high or low or truehi9) is also not really great. A low pinion rear is stronger typically then High Pinion. I would rather see a RJD60 front with a low pinion rear 9". Only issue there is a RJD60 only goes dn to 5.38 ratio.

I had the 14B and RJD60(full 8lug 1ton). I swapped it out for 9" F&R. LP rear and LP Front. I didnt have the money for a truehi9 at the moment. Also, this is being converted to a 3700 Jeepspeed, and no longer a Ultra4 stock class. SO the low pinion front 9" should survive fine. Best part is that I am able to pick almost ANY ratio every made by man... Running 5.89's...

Everybody breaks stuff at some point. I will say I Never found that point with my heavy shaved 14B and RJD60 in my XJ (both had better ground clearance then JKD44's). I ran KOH x2, Glen Helen, Blue water desert challenge, and more trails then I can count, and NEVER easy line or without care for putting 350HP to them, but only a 35" tire. I have a very strong heavily mod 4.7 stroker that has failed, but never a axle or anything inside. I hope to say the same about the 9" 's.

Unless you want to change wheels, then you really should stay with what you have axle housing wise. You can strengthen most everything you have to a point though. Is it wise, well thats like asking what the best truck out there. everyone has a different opinion. Some parts thrown at them is wise I feel. But not some of the crazy stuff that seems like smoke and mirrors...

[curtis]

Robert on curries web it says the hp 9" is 400hp and 37" tires. So what is the 44 rated at?

I think I could cut the outers off with out narrowing the housing. I'm pretty sure.

[ROBERTK]

Those numbers are pulled out of a smart persons arse. Cause a HP 9" is just a 8.8rev gear set, if thier HP9. Not to mention if its in a stock style housing, the housing is the weaker link and if you bounce alot then that will kill parts. If your in a F9 3.5" tubed trussed housing then your looking at the ujoints (If 760's) as the weak link.

Also a HPD44 with the JK gear set is likely rated higher (for the gears and bearings) then the 8.8R.

If you cut Inners off of a 1/2ton setup then no biggy but welding new ones on.

But with a 1 ton larger inner you Really should have the tube go thru the inner C and that might not be fully poss. Maybe though.

PS. do you really think a hp9 (curries or others) with a 31sp shaft and 760 ujoints are ok in say, a LJ with about 1200 lbs added and a LS motor in it, out in the rocks? Oh with 37" tires :-)

[curtis]

PS. do you really think a hp9 (curries or others) with a 31sp shaft and 760 ujoints are ok in say, a LJ with about 1200 lbs added and a LS motor in it, out in the rocks? Oh with 37" tires :-)

No I wouldn't.

[ROBERTK]

No I wouldn't.

:thumbs_up

[curtis]

But I would run a f9 with 1 ton outers and 35 spline axles lp with 40's.

[aw12345]

Daym, this thread is ALL over the place. And with some info that is not true or at least misleading.
A few things I saw that seem wrong, or came across wrong. In no particular order.

JKD44 front ujoints ARE larger then any other D44 or D30 front ujoints up till 2013. At which time now the JKD30 comes with new larger JKD44 front ujoints. They are basically the same width cross as a D60 with D44/30 caps. Huge improvement over 760's. Does this apply here in this thread, No. But I saw reference to all the same including the JKD44.

Then there's talk of a HP9 now and convert over to some D60 outers later. This seems wrong as its typed. A hp9 by currie is not reuseable if over about a 35" tire. so the only reusable part is the housing which is going to be narrowed when inners are cut off to weld on D60 inners. Unless you're talking TrueHi9. Then if you ahve the thousands for that center section, why not just do it right and get a True complete axle.

As for a RJD60 rear and a 9" (high or low or truehi9) is also not really great. A low pinion rear is stronger typically then High Pinion. I would rather see a RJD60 front with a low pinion rear 9". Only issue there is a RJD60 only goes dn to 5.38 ratio.

I had the 14B and RJD60(full 8lug 1ton). I swapped it out for 9" F&R. LP rear and LP Front. I didnt have the money for a truehi9 at the moment. Also, this is being converted to a 3700 Jeepspeed, and no longer a Ultra4 stock class. SO the low pinion front 9" should survive fine. Best part is that I am able to pick almost ANY ratio every made by man... Running 5.89's...

Everybody breaks stuff at some point. I will say I Never found that point with my heavy shaved 14B and RJD60 in my XJ (both had better ground clearance then JKD44's). I ran KOH x2, Glen Helen, Blue water desert challenge, and more trails then I can count, and NEVER easy line or without care for putting 350HP to them, but only a 35" tire. I have a very strong heavily mod 4.7 stroker that has failed, but never a axle or anything inside. I hope to say the same about the 9" 's.

Unless you want to change wheels, then you really should stay with what you have axle housing wise. You can strengthen most everything you have to a point though. Is it wise, well thats like asking what the best truck out there. everyone has a different opinion. Some parts thrown at them is wise I feel. But not some of the crazy stuff that seems like smoke and mirrors...

Jk D44 aftermarket Chromemolly front shafts use spicer 760 U joints atleast that's what the proud owner of a TJ with JK axles and the fancy stuff in them claims, he paid the bill so ought to know. Stock shafts do use a larger U joint though.

[ROBERTK]

Jk D44 aftermarket Chromemolly front shafts use spicer 760 U joints atleast that's what the proud owner of a TJ with JK axles and the fancy stuff in them claims, he paid the bill so ought to know. Stock shafts do use a larger U joint though.

Nope. Pretty much All 4340 kits now use jk d44 joints.

Year's ago superior and dana trac used to only offer the 760 sized. Only cause they had to offer something.