universal joints

I have had u joints fail on cars, usually preceded by an unbalanced vibration that is on a different frequency than the engine or wheels, It will also change intensity when you back off the accelerator. I have seen some complete failures resulting in the drive shaft dropping into the pavement and tearing up the under-body.
The new sealed ones do last longer in my estimation but if I were to have a mechanic do an under-body inspection at 80,000 miles, I would include the universal check, along with transmission flush, rear end flush, tie rods, breakes etc

pops

DUNEBUGGYDOUG wrote:
grease fittings will weaken a u-joint

I've seen busted yokes on Both when the bearings failed/seized.



Everyday use......non-greasable are great

Wet use....greasable provided one actually greases them.

With the vehicle off, in park or in gear, climb under it and try turning the driveshaft by hand. Watch for any movement within the U-Joint, you may get some "play" from the yoke which may be normal. Look closely as you turn and wiggle the D-shaft for play in the cups of the joint, you will probably have both hands on the D-shaft when you do this, don't be too gentle.

DUNEBUGGYDOUG wrote:
grease fittings will weaken a u-joint

While I guess this is technically true... so what? Lack of grease in the cup/needle bearings is what causes them to fail. I've never had a cross break.

grease fittings will weaken a u-joint

One with a lot of sideways movement. Need to try moving in four different directions... 90 degrees.

some have grease ftings others are sealed . I,ve put 100k on my trucks and there sealed ,no failures. but I,m old school wish everything had grease fittings.