GMT900 Slip Yoke Lubrication

**Zembonez** · #1 10-18-2009, 02:40 PM

Pulled the driveshaft today and greased the slip yoke. What a difference! Takeoffs are smoother than ever... It's hard to believe how such a small thing can make a difference.

Walk through:

FIRST. Set the parking brake. Once the driveshaft is removed, the truck can roll even when in Park... and it will!

Make sure to mark the driveshaft, U joint, & rear end so that you know everything goes back together exactly
as it came apart for the sake of maintaining balance. A simple china marker works well.

Here is the front with the slip yoke still installed in the trans.

Remove the 4 U joint retaining bolts. Tap the shaft at the U joint with a dead blow hammer to dislodge.
Slip the driveshaft forward until the U joint clears and then slide it rearward out of the transmission.

NOTE:
USE CAUTION to prevent the 2 exposed U joint caps from falling off. Some people like to wrap tape
around the joint to keep the caps on. Mine were not trying to fall off, but there isn't anything (except
the grease in them) keeping them in place when the shaft is removed.

Trans will not leak fluid as long as vehicle is level.

Yoke after removal. Notice how much surface rust is on the exposed part of the yoke after two years.

Take a scotch pad to the exposed portion and remove the surface rust.

After smoothing it, there is an obvious improvement in the yoke. This step is NOT totally necessary, but this is where
the yoke goes through the rubber dust boot on the trans tailshaft, so I like to make it smooth again.

After cleaning out the OEM grease, I lube the inner splines using Marine grade wheel bearing grease. This product has
proven to be an unbeatable lubricant for this purpose over time. I've used it on several trucks.

Nothing beats a good old finger when it comes to smoothing the grease out in the splines.

Installation is the reverse of removal. Just make sure that you align your marks so that everything goes back together as it was.

Headed off on a test drive after about 15 minutes of work!

CJ Hungus · #2 10-18-2009, 03:01 PM

I'll be doing this tomorrow! Great write up Jim

Bowtie2Sierra · #3 10-18-2009, 03:10 PM

Thanks for the write up. I always wanted to grease the slip yoke on mine as well. However, I'm a dummy when it comes to transmissions and I had no clue what the slip yoke was or what it entailed to grease the splines. I have a better idea of what I'm looking for now thanks to your write up.

CJ Hungus · #4 10-18-2009, 03:14 PM

Quote:

Originally Posted by Bowtie2Sierra

Thanks for the write up. I always wanted to grease the slip yoke on mine as well. However, I'm a dummy when it comes to transmissions and I had no clue what the slip yoke was or what it entailed to grease the splines. I have a better idea of what I'm looking for now thanks to your write up.

Exactly.... to this day there has never (that I know of) been a good solid write up on greasing the slip yolk. It was always... just pull the driveshaft out and gease the slip yolk. That doesn't help me

much

**Zembonez** · #5 10-18-2009, 03:21 PM

It's easy guys. Just MAKE SURE you mark the driveshaft and don't rotate anything while it's out. Install it the same way it came out and it's a snap!

CJ Hungus · #6 10-18-2009, 03:28 PM

Quote:

Originally Posted by Zembonez

It's easy guys. Just MAKE SURE you mark the driveshaft and don't rotate anything while it's out. Install it the same way it came out and it's a snap!

Well now that we have this write up, it should be a snap! What brand of wheel bearing grease do you use?

**Zembonez** · #7 10-18-2009, 03:33 PM

I use Marine grade wheel bearing grease like a boat trailer would use. I figure if it's good enough for being used in submerged wheel bearings, it should be fine on the slip yoke. I've used it on my trucks since my 2001 came down with the slip yoke bump problem. I'm sure any car part store or even a Walmart type store would have it.