what to look at when buying used axles

Found what i think is a good deal on some built axles off of a forum member..

Front is a H.p. dana 30 with 4.56 gears, ARB, 30 spline chromoly shafts, tube seals, spicer u-joints, lower control arm skids, newer unit bearings.

Rear is 8.25 with 4.56 gears, ARB, 29 spline chromoly shafts. Riddler heavy duty diff covers front and rear. Ready to bolt in.

roughly 10-15K mi.

"From an xj that rolled on the road, the owner was running without sway bars. The axles don't appear to be affected in any way, no apparent cracks, no wobble when rolling. No the compressor is not included but the switches, solenoids and lines are, one of the switches may be bad, it doesn't click"

$1500 plus about a 9 hour round trip.

Seems like a great value what do you guys think?
Anything i should be looking at when i pick them up? I did ask him if i could open the diff to take a peek in there.. but really all i would know is it seems to look ok and i could count teeth to check gear ratio..

any way to test an arb on the fly?

this is alot of $ on my current budget but i can swing it . what do you guys think. im a little nervous about ending up having issues with them ( i suppose thats the risk im taking)..

Anyway any thoughts would be appreciated

im pretty much sold on them just dont know what to look at when picking them up..

Check both housings for straightness. Make sure no brackets look bent or folded. Look for cracks or chips on the gears. Does it come with steering?

Put compressor on the arb 90 psi I believe see if they lock

I think you main concern is that the axles are straight.
Front Axle: at the minimum un-bolt the unit bearing from the axle and slide the axke part way out until the axle splines are disengaged
from the carrier. Rotate the axle and re-seat the axle into the carrier. If the axle is straight, it will slide right back in. If its bent, it won't. I have no idea how you'd check the rear.

dont think steering comes with it as it wasnt mentioned ,, i recently replaced all my joints in my stock (weak) Steering though

Uh, what? Straightedge and measuring device.

Remi rolled his Jeep on the road one time, swapped the axles under a new rig, and broke a housing on the Rubicon. That was funny.

I paid $750 for a used (10K) 8.25 with the same stuff as the one you're looking at, with receipts for the build. I paid $1K for a used HP 30, with TNT high steer knuckles, CTM joints, Ox locker, trussed, Vanco brakes, and all the steering parts. So, $1500 isn't too bad for both axles, but not a complete steal. Though it would cost a whole lot more to have the work done on your existing axles.

You can charge the ARB with 75-120 PSI, at very little volume. The trick would be to make a tight connection so you can listen for any air escaping from inside the differential. Especially on the front, if the there is excessive side play in the carrier, the seal housing may leak, particularly as you turn the axle. Of course, turning it with any load is impossible with the axles out of the vehicle.

You can calculate the gear ratio without pulling the cover. Just rotate the pinion and count how many times it turns for a revolution of the axle. If I remember correctly, if you keep one axle from turning, the other one should rotate twice as fast as the actual ratio. But, pulling the cover will let you look for shiny parts in the fluid, and see what the contact pattern looks like.

David Bricker / SYR

Phil, I think that method would work for the rear axle.
It would work OK for the front axle up until the inner C.