[BulldogTJ98]

Im installing a custom built Dana 44 High Pinion in my 98 TJ with a 3 inch suspension lift and about a 1'' TC drop kit. I dont have a slip yoke eliminator kit yet but I would like to install my HP D44 w/ 4.88s and Detroit locker now. I was just wondering... Can I put the axle in, measure the distance between yokes, get my driveshaft shortened and use a step-down U-joint for now? And still use my slipyoke driveshaft? I should be able to remove my TC drop also because of the location of the High Pinion.
Thanks

[BulldogTJ98]

Bumpidey Bump bump buuuump...

[flatlander757]

Originally Posted by BulldogTJ98

Im installing a custom built Dana 44 High Pinion in my 98 TJ with a 3 inch suspension lift and about a 1'' TC drop kit. I dont have a slip yoke eliminator kit yet but I would like to install my HP D44 w/ 4.88s and Detroit locker now. I was just wondering... Can I put the axle in, measure the distance between yokes, get my driveshaft shortened and use a step-down U-joint for now? And still use my slipyoke driveshaft? I should be able to remove my TC drop also because of the location of the High Pinion.
Thanks

If I'm reading this right it is going in the rear of your Jeep.

First off, a high pinion axle in the rear is a terrible idea since the pinion is riding on the coast side(not the drive side) of the ring gear. So you've basically got a D44 that is 30% or so weaker than a standard TJ D44. The opposite holds true for the front, where a low pinion is weaker than a high pinion due to the wheels turning the opposite direction relative to the ring/pinion. In all honesty it's not that huge of a deal in the front since the rear does majority of the work, but in the rear I'm pretty sure it's asking for trouble. I haven't seen ANY HP rear D44s, but I have been lucky enough to see a Hi9(not a True Hi9) shatter the entire case in half under a Bronco on 35s.

Provided your HP44s pinion yoke takes the same 1310 u-joint that your stock axle does, you can possibly get away with just using the stock shaft for now. I'm sure with the pinion being physically further up and closer to the t-case it will work fine. Just make sure the slip-yoke can move in and out far enough to not cause concerns in both directions. I'm assuming you are swapping out a D35? If so your driveshaft will possibly be a tad too long if anything. If you had a regular rotation D44 then it will likely be just right as the 3" lift would negate the pinion being closer now that it's high pinion. This is all speculation but without measuring anything that's about the best I can do.

What I did was buy a SYE, installed it, measured for my driveshaft and ordered it from Tom Wood, and then in that time I drove around in FWD 'til it arrived.

[BulldogTJ98]

right on man.
Ya this HP Dana 44 is from the back of a TJ that is owned by a dude that owns a Jeep Fabrication shop. Its this guys 8th rock crawler and let me tell ya, this thing is ronchy! I know, ive never seen a high pinion dana 44 in the rear either, but you should see this thing, its been chopped, braced and all sorts of heavy duty stuff done to it. Anyways, i was just wondering if the slip yoke would be okay with pushing the 4.88s in that D44.

[BYuen]

It should be ok. If anything that HP axle will help with your driveline angles decreasing your chances for getting vibes.

[mrblaine]

Originally Posted by flatlander757

If I'm reading this right it is going in the rear of your Jeep.

First off, a high pinion axle in the rear is a terrible idea since the pinion is riding on the coast side(not the drive side) of the ring gear.

Truly not an issue unless you wheel where wheelspin is needed to traverse the obstacles. There are far too many important advantages the HP has over the LP to even consider most LP options. Another reason I'm not that big of a fan of 8.8's. Goes against my philosophy of maximum gain for minimum effort. Why go to all the work to swap in an axle and still have a LP?

So you've basically got a D44 that is 30% or so weaker than a standard TJ D44. The opposite holds true for the front, where a low pinion is weaker than a high pinion due to the wheels turning the opposite direction relative to the ring/pinion.

Care to try that one just one more time? The ring and pinion still have to turn the same direction because the vehicle still has to go forward and the motor don't run too well backwards.

In all honesty it's not that huge of a deal in the front since the rear does majority of the work, but in the rear I'm pretty sure it's asking for trouble. I haven't seen ANY HP rear D44s, but I have been lucky enough to see a Hi9(not a True Hi9) shatter the entire case in half under a Bronco on 35s.

Yeah, and some folks can break an anvil in a padded room with a rubber mallet. Don't let one example of idiocy be the rule. That's clearly an exception. I ran a pair of Currie Hi-9's for 3 years on 37's and although I did tend to wear them out a bit faster than normal, I never broke one. (I was a test case for Currie)

Provided your HP44s pinion yoke takes the same 1310 u-joint that your stock axle does, you can possibly get away with just using the stock shaft for now. I'm sure with the pinion being physically further up and closer to the t-case it will work fine. Just make sure the slip-yoke can move in and out far enough to not cause concerns in both directions. I'm assuming you are swapping out a D35? If so your driveshaft will possibly be a tad too long if anything. If you had a regular rotation D44 then it will likely be just right as the 3" lift would negate the pinion being closer now that it's high pinion. This is all speculation but without measuring anything that's about the best I can do.

What I did was buy a SYE, installed it, measured for my driveshaft and ordered it from Tom Wood, and then in that time I drove around in FWD 'til it arrived.

[flatlander757]

Originally Posted by BulldogTJ98

right on man.
Ya this HP Dana 44 is from the back of a TJ that is owned by a dude that owns a Jeep Fabrication shop. Its this guys 8th rock crawler and let me tell ya, this thing is ronchy! I know, ive never seen a high pinion dana 44 in the rear either, but you should see this thing, its been chopped, braced and all sorts of heavy duty stuff done to it. Anyways, i was just wondering if the slip yoke would be okay with pushing the 4.88s in that D44.

Must see pics

Originally Posted by mrblaine

Truly not an issue unless you wheel where wheelspin is needed to traverse the obstacles. There are far too many important advantages the HP has over the LP to even consider most LP options. Another reason I'm not that big of a fan of 8.8's. Goes against my philosophy of maximum gain for minimum effort. Why go to all the work to swap in an axle and still have a LP?

I guess you either choose a trade-off between potential strength and ground clearance. Fair enough.

Care to try that one just one more time? The ring and pinion still have to turn the same direction because the vehicle still has to go forward and the motor don't run too well backwards.

No no... you didn't understand. They are physically moving the same direction in relation to each other, but in the front looking at the diff case the pinion spins counter-clockwise to move the Jeep forwards. In the rear the pinion spins clockwise to move the Jeep forwards. This is why the pinion in a LP axle applies it's force on the "coast" side in the front and the "drive" side in the rear.

Yeah, and some folks can break an anvil in a padded room with a rubber mallet. Don't let one example of idiocy be the rule. That's clearly an exception. I ran a pair of Currie Hi-9's for 3 years on 37's and although I did tend to wear them out a bit faster than normal, I never broke one. (I was a test case for Currie)

Oh I understand that fully, just stating my experiences.

[mrblaine]

Originally Posted by flatlander757

No no... you didn't understand. They are physically moving the same direction in relation to each other, but in the front looking at the diff case the pinion spins counter-clockwise to move the Jeep forwards. In the rear the pinion spins clockwise to move the Jeep forwards. This is why the pinion in a LP axle applies it's force on the "coast" side in the front and the "drive" side in the rear.

Oh I understood perfectly, you just didn't explain it very well. You should have stated that because the driveshafts, axles, and tires still have to turn the same direction, what gear makers did was reverse the spiral on the pinion and flip the teeth on the ring gear when they moved them from below to above centerline on the axle.

The reversal and flip are what inverts the drive and coast sides.

Oh I understand that fully, just stating my experiences.

Your experiences or just seeing that one event without knowing the history of the rig, driver, terrain and driving style?