Driveshaft Play, "Clunks" Into Drive and Reverse

[SourTooth307]

Not sure how to tackle this one. Could it be U-Joints? How do I properly diagnose this one? I can feel the play in the driveshaft if I pop the truck into neutral, crawl under it, and twist the driveshaft by hand.

[MountainGoat1966]

Sounds like U joints to me.

I had play in one of mine, replaced it, and the old one wasn't even dry or worn bad.

[motornut]

have a look at them,try to grease em, are they the originals?
the gap should be even all around it(mine had uneven space on lower left)
but grab it,if it moves/jiggles/noisey it's time.
i call it a "ping" seems to resonate up the shaft.
could mark it's position,remove and inspect,but watch sliding the end cap off...
loose a needle bearing and gona have to do them.

[Keith Seymore]

When you can move it by hand does the rear axle pinion flange move too? (or just the u joint)?.

Just trying to determine if it is excessive lash in the rear axle.

K

[SourTooth307]

Originally Posted by Keith Seymore

When you can move it by hand does the rear axle pinion flange move too? (or just the u joint)?.

Just trying to determine if it is excessive lash in the rear axle.

K

I think so, yeah.

[savatreatabvr]

Crawl under the truck and grab the rear pinion flange, aka (yoke) it's what the rear u-joint bolts to and push up and down! If there's play it's time to replace some pinion bearings! I recently had the same thing happen to the point where I almost dropped the drives haft doing 70 mph down the freeway! Remember, yoke movement up and down if bad, bad bad!

[SourTooth307]

Originally Posted by savatreatabvr

Crawl under the truck and grab the rear pinion flange, aka (yoke) it's what the rear u-joint bolts to and push up and down! If there's play it's time to replace some pinion bearings! I recently had the same thing happen to the point where I almost dropped the drives haft doing 70 mph down the freeway! Remember, yoke movement up and down if bad, bad bad!

So it's been a while but I finally had an opportunity to crawl under the truck and twist the driveshaft around. Turns out the play is coming from the yoke and not just the shaft. I didn't notice any up and down play, but it does twist. So on to these pinion bearings, what's involved in replacing them?

[c10454]

Check the hanger or carrier bearing. The rubber isloator get old and worn and transmits a lot of noise when shifting into R or D. After changing mine its much softer and quieter going into gear.

[SourTooth307]

Originally Posted by c10454

Check the hanger or carrier bearing. The rubber isloator get old and worn and transmits a lot of noise when shifting into R or D. After changing mine its much softer and quieter going into gear.

How is that done?

[c10454]

If the rubber looks dry and cracked, if the rubber looks to be pushing out. If you can move the driveshaft by hand at the hanger bearing, the worn rubber will allow it to move. If the u-joints are worn and need to be replaced chances are the hanger bearing does as well.

[farmall]

Transfer case chain.