high pinion/low pinion?

[volaredon]

I recently was in on a front axle replacement on my buddy's XJ. his old (wreck damaged) housing was a "low pinion"; the JY replacement is a "high pinion";

1) did they offer both styles of axle, in a TJ?
2) for the same gear ratio, does "hi pinion" or "lo pinion" make a difference as far as buying ring and pinion sets?
3) same question as #2 EXCEPT as related to carrier. Do Hi pinion and lo pinion housing carriers interchange?

The reason I ask is that I am looking for a set of 3.73s for my TJ to replace some lame 3.07s. (3.73s will be plenty, for "my" usage of the Jeep) there is a member here that has talked about doing a swap from 3.73s to 4.56's and I have inquired about buying his 3.73s but need answers to avoid buying something, that is unusable to me.

 

[Bounty__Hunter]

1) All TJ's had a low pinion front axle, but the HP d3o from an XJ will bolt right in. XJ's all had low pinion except for '01 and maybe '00 when they switched to low pinion.

2) Gear sets are specific to high pinion and low pinion, the gears are cut differently depending on the position of the pinion.

3) The carriers interchange between HP and LP.

HP is desireable in the front as you get more pinion and driveshaft clearance, as well as the stronger gear mesh setup.

 

[jps4jeep]

Just to clearify BH post, all XJ's are High pinion, they switched mid year 98, 99 is considered the first year for lo-pinion. 96 is the most desirable since it has the large joints and no CAD on the axle.



To add HP is desirable for the front application for the clearence mentioned, but also becuase the way reverse cut gears engage, when your accelerating your engagment is on the drive side of the gear, this is only appliciable to a HP in teh front, a HP in the rear your engagement would be on the coast side of the gears, and while it will work, probably for the life of the diff, it is not ideal in hi torque situations