Slip Yok on Drive Shaft

[BigO]

I have a 2001 HD short bed, ext cab.

When ever I take off I get a clunk noise in the rear end. My dealer says that is normal because they use a slip yok, so that when you take off the drive shaft moves. I am not up on drive shafts, I need to know if they are blowing smoke up my rear. I have complained about this before and do not get anywhere. If this situation will cause me problems down the road then I want to get this resolved. Any bulletins etc on this?

Thanks for your imput.

[More Power]

The spline on slip yokes can wear over time, creating a ridge where the upper (compressed) wear line is on the spline. Stopping causes the rear axle to rotate slightly causing the slip yoke to extend a bit. Then, accelerating from a stop causes the slip yoke to compress as the axle rotates in the opposite direction due to torque. This process can cause the yoke spline to ride over the previous mentioned ridge to produce a bump/clunk/etc.

If it's annoying, you can replace the slip yoke (most likely the center one on a 2-piece rear drive shaft).

MP

[BigO]

MP:

If it was your truck what would you do? It is some what annoying. I only have 40,000 miles on it, would it need replacing already?

Why might it be the middle one. I understand what you are describing but I thought the yoke would be attached to the drive shaft that enters the differential. Is there more then one yoke? If so where are they located. Exactly what does a yoke do?

[DmaxMaverick]

The slip yoke allows the shaft to extend/contract with suspension changes. A common fix is to separate the yoke from the spline and lube it with some lithium grease. It is not a permanent repair, but should last 15,000 miles or more.

It's easy. Drop the shaft and separate the spline from the yoke and pack it with the grease. If you were so adventurous, you could install a couple grease zerks to facilitate it into your normal service interval. I haven't had a problem with mine, but that would be my remedy when/if it happens.

[ 03-12-2005, 08:51 PM: Message edited by: DmaxMaverick ]

[madmatt]

a small amount of driveline slop is not only normal but also nessacary to maintain clearences in your rear diff. if yours is really excessive or just plain annoying, GM offers an updated slip yoke. the new yoke may or may not include a new u-joint. if not you'll have to buy one of those as well as the factory joints are held in w/ the plastic retainer that has to be melted out.

[More Power]

BigO, My truck has 43,000 miles on it, and it too has the bump I was talking about in an earlier post.

This truck is still equipped with the original 2-piece rear driveline, even though it was elegible for the factory re-fit of the aluminum one-piece. This truck never exhibited the launch shudder some had, so I felt it was better to maintain the originally engineered 2-piece rear drive shaft.

I may disassemble the rear driveshaft this spring and lube the spline as DM mentioned above. If I do (most likely will), you'll be able to read all about the process in a tech piece. smile.gif

MP

[BigO]

Thanks Folks.