junkyard D30 question

so I'm putting in a D30 from a 97 to match the D44 3.55 gears in back. It had 66,000 miles on it, and all the seals look good. I haven't had a chance to look at the u-joints or ball joints, other than to notice it looked like they were greased once and a while.

My question: should I replace the ball joints and u-joints, or run them?

Also, what's the easyest way to check them?

Thanks!
mike

to check the ball-joints jack it up, and give the tire a shake with your hands at 6 o'clock and 12 o'clock on the tire. that'll give you an idea of what shape your ball-joints (or more likely your unit bearing) is in. then, take a prybar and press up on the tire. there should be no movement (or less then .030") between the axle "c" and knuckle. the ball-joints on jeep usually don't exhibit much movement using the first method, from my experience, so using the second method seems like a more accurate way to check them.

to check the u-joints i usually jack it up and turn the wheels, then spin the tire slowly. if a joint is sticking, it'll slow the tire down, and try to pull the tire back straight. that's about the best way i know of, other than pulling the shafts, which only takes a few minutes anyways.

what if the axle's sitting on jack stands, not attached to the jeep?

If the stud moves easily, replace them.

FWIW, I'd install new ones now instead of waiting.

install new now, then you won't have to say "I should have" after it breaks....and if it still breaks you did all you could

I'd do the u joints now, and check for play in the ball joints, If the knuckle just flops around replace them, I found the ball joints easier to do once the axle was installed and on the hoist (doesn't move around when your trying to work on it

that's true. i'd get it attached to the jeep, then do the ball joints. they're CAKE to do on the 30s...