Are HPs necessary

[SwampTJ]

I'm about to hit the local junkyards lookin for some 60s. I got to wonderin, what is the main reason people go with hp axles in Jeeps? Driveline angles, ground clearance? Would a hp 60 have to be put in the rear on a TJ with 8"+ suspension lift? I wonderin because I would rather spend less on the regular junkyard 60, but if a hp is needed then I would spend the $$. Also my TJ is built for mud, no rocks in South La. so the ground clearance of the axle shouldn't be a big issue compared to getting over rocks. I'm thinkin after the TJ brackets are welded on at the right angle it shouldn't be a big deal if it's hp or not. Am I on the right track here, remember my TJ may never see a rock, but it will see the bottom of a few swamps. <IMG SRC="smilies/jeep2.gif" border="0">

[The Rockslut]

On short wheelbase vehicles the HP makes it very nice for driveline angles. The HP isnt that much help for ground clearance.

Driveline angles. But if you're only running mud, why the need for 60's? I would think running rocks would put the most force on the axles, not the mud where tire slippage would help keep you from breaking. Any other opinions?

[UGET IT]

Your lift isnt important as much as your tire size.........tire size will determine the clearence at the housing. I ran 35's and 36's and was always hitting my Dana 60. I recently put on 38x14.50 SX's and its all good.! <IMG SRC="smilies/biggrin.gif" border="0">

[badassjeepguy]

Originally posted by Rockslut.:
<STRONG>On short wheelbase vehicles the HP makes it very nice for driveline angles. The HP isnt that much help for ground clearance.</STRONG>

ohh id have to argue with that one... <IMG SRC="smilies/biggrin.gif" border="0"> since i have been running hp's at both ends it is pretty hard for me to eat d dhafts with rocks... i can still do it, but alot harder to do... im clearing shit with 39.5's that guys with 44's low pinion and t cases dropped are'nt

on the mud side, if you run high pinions and push everything up into the frame rails you will have less shit to drag through the mud... id say go hp, you wont regret it.

[SwampTJ]

Well 38"+ tires and 350hp will need 60s. That's what I aimin for anyway, I want to get the axles out the way first & this is gonna take several years to do. I asked this because I've never really seen the issue of hp60s, mud & TJs addressed before. 99% of all jeep boards deal with rock crawling. I'm at 35s now with a 44, 1 moser & 1 superior shaft. I know not as much stress is put on axles in mud but it's that cleanin of the tires & startin & stoppin in 3ft of clay that will put a big load on the axles. I guess what I'm tryin to ask is will a TJ need a rear hp axle with 8+" of lift with a 60 rear & no less than 38" tires that will be used in mud?

[SwampTJ]

Originally posted by badassjeepguy:
<STRONG>on the mud side, if you run high pinions and push everything up into the frame rails you will have less shit to drag through the mud... id say go hp, you wont regret it.</STRONG>

That's a good point I hadn't considered yet. But couldn't a grinder get me close to the clearance of a hp? What is the actual difference in clearance between a hp & lp?

[badassjeepguy]

id say yes or you will have to lower the t case and that will give you less clearance... and drag shit in the mud

[badassjeepguy]

Originally posted by SwampTJ:
<STRONG>
That's a good point I hadn't considered yet. But couldn't a grinder get me close to the clearance of a hp? What is the actual difference in clearance between a hp & lp?</STRONG>

i aint quite sure what the hell you could grind to make a low pinion higher.. <IMG SRC="smilies/rolleyes.gif" border="0">

[wngrog]

There won't be noticable clerance gains at the bottom of the housing, he is talking about keeping his driveshafts out of the rocks.

As for me, I HAD to go HP due to my 18" driveshaft in the rear of my Cruiser when I added the Altas.

I would guess you will be OK with low pinion D60's with the setup you are looking at.

[badassjeepguy]

Originally posted by wngrog:
<STRONG>There won't be noticable clerance gains at the bottom of the housing, he is talking about keeping his driveshafts out of the rocks.

As for me, I HAD to go HP due to my 18" driveshaft in the rear of my Cruiser when I added the Altas.

I would guess you will be OK with low pinion D60's with the setup you are looking at.</STRONG>

yeahh, i think it would work too, but if ya do the hp you would never regret it... its nice to have only control arms and axles below the framerails.. <IMG SRC="smilies/biggrin.gif" border="0">

[SwampTJ]

Originally posted by badassjeepguy:
<STRONG>
i aint quite sure what the hell you could grind to make a low pinion higher.. <IMG SRC="smilies/rolleyes.gif" border="0"></STRONG>

I was talkin bout the the clearance from the bottom of the diff to the ground, not about driveshaft height. I know a hp would be best but I don't know of any hp rears that can be found in a junkyard.

[ 09-06-2001: Message edited by: SwampTJ ]

[camo]

no such thing as a hp rear. you need to build it from a front.

[badassjeepguy]

Originally posted by camo:
<STRONG>no such thing as a hp rear. you need to build it from a front.</STRONG>

ha ha ha, ya got a point... didnt think we had to go into that depth, but maybe we did... <IMG SRC="smilies/biggrin.gif" border="0">

[SwampTJ]

Originally posted by camo:
<STRONG>no such thing as a hp rear. you need to build it from a front.</STRONG>

Exactly hoss, that was the point, get a junk 60 for cheap or have a hp one built $$$. I thought I covered that when I said don't know of any hp rears that can be found in a junkyard. <IMG SRC="smilies/thefinger.gif" border="0">

[YellowSub1962]

Originally posted by Jeepster1220:
<STRONG>Driveline angles. But if you're only running mud, why the need for 60's? I would think running rocks would put the most force on the axles, not the mud where tire slippage would help keep you from breaking. Any other opinions?</STRONG>

<font color="yellow">This is not usually the case unless your running in a perfect bog. Then you would be running in the "loose" mud and spinning your tires till the finish line where you shut down the power before your tires have a chance to hit the "hard pack".

So its actually the opposite in most real world situations. You'll be spinning all fours in the mud, then all of a sudden a tire will hit a rock, the uneven bottom of the mud hole, or grab some sort of traction while you're foot it still to the floor. Your axles need to be able to absorb this shock load otherwise you end up like this:



I was spinning all fours when the left front grabbed traction. The wheel slowed down (read stopped) and the axle kept going...

In rocks, the axles need a high sheer stregnth, but are not usually (ARCA comps not included) shock loaded to the same extent as a mud axle... Hope this makes sense..</font c>

[yjtj]

hp is bad if you clock your t case and are running a auto tranny. the d shaft will hit the pan. in the middle of building mine now and im concerned about the low pinion and t case which is clocked flat. a high pinion would have no chance

[Mike Knorr]

High pinions just work better in most situations when you are dealing with short wheelbase vehicles. Moving the drive shafts up allows you to move other parts up. This can smooth the bottom of the rig and provides a better break over angle. The less crap hanging down the better.

[TEX]

With 350HP & 38's, 60's could be overkill for a mud machine of TJ weight - especially in the front. A lot of the mud guys around here run a semi-floating or ff 60 in the rear of CJ's with Dana 44's up front & 38.5" Boggers. But, these guys are turning 800HP & more. With 350HP & 38's, I'd be inclined to run 44's front AND rear.

TEX

[P&T Jeeps]

Not that it will matter to you now, but remember by running HP's in the rear you will be running on the coast side of the ring gear which will reduce strength...

[badassjeepguy]

Originally posted by P&T jeeps:
<STRONG>Not that it will matter to you now, but remember by running HP's in the rear you will be running on the coast side of the ring gear which will reduce strength...</STRONG>

that may be true but we are talkin 60's here

[P&T Jeeps]

I know, just saying...

[SwampTJ]

Originally posted by TEX:
<STRONG>With 350HP & 38's, 60's could be overkill for a mud machine of TJ weight - especially in the front. A lot of the mud guys around here run a semi-floating or ff 60 in the rear of CJ's with Dana 44's up front & 38.5" Boggers. But, these guys are turning 800HP & more. With 350HP & 38's, I'd be inclined to run 44's front AND rear.

TEX</STRONG>

Hmmm, sounds like the man I needed to hear from. 60s overkill, no such thing <IMG SRC="smilies/glasses.gif" border="0">. Really 44s front & rear? Are these guys that run the ff 60s in the rear of CJs have hp or lp axles? <IMG SRC="smilies/jeep2.gif" border="0">