I'm looking at getting 4.10 gears for my dad this Christmas. Are reverse cut gears for front axles converted to rear-steer applications or just a different way to cut them? Would I need to get regular cut or does it really matter? TIA

 

If you have an Xj with the stock front Dana30, it is a high pinion axle and needs a reverse cut ring and pinion set.

 

The typical front axle is essentially a "flipped" rear axle housing, and takes the same gears (with the pinion axis below the shaft centrelin.)

A "reverse spiral" gearset is one that is meant for a front axle with the pinion axis above the cetrenline of the shafts. Due to the nature of a hypoid gearset, the spiral must be reversed to allow the gear teeth to mesh.

(NB: I say "essentially" flipped, because an LP front axle is not a flipped rear axle. If you try to flip a rear axle to make a front, the bearings are going to end up starved for lubrication and will self-destruct. The housing gets redesigned to accommodate the gearing and lubrication.)

It's easy to tell whether or you you'll need reverse spiral gearing - if the pinion axis is above the axis of the halfshafts, you'll need reverse spiral gears. If the pinion axis is below the axis of the halfshafts, you can use standard spiral gears.

High pinion front axles are a bit less than common - they're out there, but finding them outside of the D30 front in AMC and early ChryCo Jeeps takes some doing sometimes...

 

I thought most D30 XJ's are High Pinion...........only late ones (00-up?) came with Low pinion was my understanding????? I could be wrong