How To Grease The Slip Yoke

TILTED1 · November 3, 2009

No need for a "special" grease... and no, it won't contaminate your trans fluid.

Read this: http://www.truckmodcentral.com/forums/showthread.php?t=2504

I'm a noob to this and don't know much about trucks, but am good with my hands and figure I can tackle this since i was able to put on my old level kit. I have a 2wd and have the horrendous "clunk" when i come to a complete stop and take off from a stop and I cant take it any longer. From the write up, it looks like the yoke came from the front of the drive shaft from the tranny and not the rear of the drive shaft from the rear differntial. Is the yoke that I should be greasing in the front or the rear of the drive shaft? Sorry its a noob question, but that's why i come here to get great information and answers from you guys.

It becomes obvious when you remove the shaft. The rear bolts up and the slip yoke is in the front where it enters the trans.

Cheers!

Thanks Jim!

So I greased the slip yoke on Friday, used a high temp marine grade grease from the local auto shop. only took about 20 to 30 minutes because I took my time and was it the first time i have done this. Wish i would have done this 10K miles ago! Drove the truck all weekend at least 60 to 70 miles and the "Clunk" is gone!

What grease did you use? I'm going to tackle mine this weekend.

I used a grease from Lucas oil products called red and tacky #2, it is high temperature marine grade 540 degree drop point grease.

TILTED1 · November 3, 2009

...and how much did you add?

I used about two ounces or so, and packed it in the yoke. been about 200 miles now and still no "clunk"!

dakota29 · November 3, 2009

Did any one get a 'service 4WD' on the message center that went away after the slip yoke lube? I am getting a constant message after I start driving lately, and the clunk when I step on the gas hard....

I am wondering if the drive shaft is hanging up and causing the service 4WD message?? Just a shot in the dark, but I thought I would ask... I will lube the yoke this weekend and see if it helps......

Mossyoakglock · November 4, 2009

What about the Lucas X-tra Heavy Duty Grease? It says it is virtually washout proof, waterproof and stable in all temps. It looks like it is like the Red N' Tacky, just a little more heavy duty. Should I be ok with using the X-tra Heavy Duty? Should stick with the Red n' Tacky or any other Marine grade grease?

Zembonez · November 4, 2009

I've had very good success with synthetic base "marine" wheel bearing grease. I originally had it for my boat trailer. Works like a champ.

joutlaw · November 7, 2009

I just removed the driveshaft and greased the slip yoke.

The end cap came off of one of the u-joint ends when I was getting the driveshaft out. I didn't lose any needle bearings from what I can tell, but I was wondering if that's normal for the caps to come off? Both u-joints had zerk fittings so I don't know if these are stock or if someone replaced them before I bought the truck. It's a 04 RCSB Z71 with 126K miles.

Zembonez · November 7, 2009

I just removed the driveshaft and greased the slip yoke.

The end cap came off of one of the u-joint ends when I was getting the driveshaft out. I didn't lose any needle bearings from what I can tell, but I was wondering if that's normal for the caps to come off? Both u-joints had zerk fittings so I don't know if these are stock or if someone replaced them before I bought the truck. It's a 04 RCSB Z71 with 126K miles.

The end caps are held in when the ujoint is bolted into the rear yoke. Nothing to worry about, but it should be noted to use caution when removing the shaft NOT to let the caps come off.

Mossyoakglock · November 10, 2009

Anybody ever used Quicksilver Marine Grease? It looks like it's made by Mercury/Mercruiser. Would that work?

pckhalil · November 18, 2009

Is this the same clunk that a guy might hear when making a few consecutive shifts between reverse and drive, usually when making a 2 or 3 point turn? The clunk happens as soon as the transmission shifts, even with my foot still on the brake. Sounds like it's coming from the middle to rear part of the truck, like slack somewhere in the drivetrain...

pckhalil · November 18, 2009

I still don't quite understand how the grease could get into the transmission/transfer case. Shouldn't there be a complete seal between the inside of the trans/t case and male spline? You can't tell me that little rubber boot on the driveshaft is the only thing keeping the fluid from leaking out?

dlstewart01 · November 18, 2009

I still don't quite understand how the grease could get into the transmission/transfer case. Shouldn't there be a complete seal between the inside of the trans/t case and male spline? You can't tell me that little rubber boot on the driveshaft is the only thing keeping the fluid from leaking out?

OK, I won't tell you that, but it is. There is a tail shaft rubber seal that the slip yoke fits through. It goes past the seal and into the transmission tailstock. If the grease should break down it can run into the tailshaft and mix with the small amount of fluid that is in there, It could work its way into the trans body. People who know more than I do say moly and other grease additives should not get on the clutch plates. I don't take that chance......

I have an exploded view of a 4L60E somewhere in my garage that shows this...but i'm too lazy to go find it. You guys just do what you want to.

Experience is the best teacher........

Zembonez · November 18, 2009

The seal at the yoke is the only seal for the rear of the trans. If you were to remove the trans and tip it toward the rear, fluid would run everywhere. There is no fluid under pressure anywhere near the tail shaft. The bearings for the tail shaft are inboard and lubricated by the trans fluid but they are not near the rear of the trans. The seal at the driveshaft is there as much for keeping dust and dirt out as it is for keeping fluid in. The grease added to the splines is virtually impossible to get in the transmission. In fact, the factory squirts a shot of grease into the slip yoke when it is installed.

pckhalil · November 18, 2009

The seal at the yoke is the only seal for the rear of the trans. If you were to remove the trans and tip it toward the rear, fluid would run everywhere. There is no fluid under pressure anywhere near the tail shaft. The bearings for the tail shaft are inboard and lubricated by the trans fluid but they are not near the rear of the trans. The seal at the driveshaft is there as much for keeping dust and dirt out as it is for keeping fluid in. The grease added to the splines is virtually impossible to get in the transmission. In fact, the factory squirts a shot of grease into the slip yoke when it is installed.

A perfect explanation, makes perfect sense. Thank you sir

WaterGuy · November 19, 2009

Did the lube job on the two-piece drive shaft on my '03 Savana with 200,000 miles.

The yoke into the trans was wet with fluid in the splines.

No obvious binding issues there.

Now the slider section is a different story.

It had grease but was kinda dry.

I cleaned the male section very good.

Too much effort to clean the female section so I skipped it.

Put some good dollops of the GM Special Grease into the female section.

Lubbed up the male section real good.

As I inserted the male section into the female section I worked it in and out to get the Special Grease all the way into the female section.

I relubbed the male section and worked it some more to ensure the parts slide in and out real smooth.

Drove it today and didn't notice any clunkin'/bumpin' which I was having,

Some pointers:

1) Mark the yoke to trans position so you can reinsert it in the exact spline position.

2) Same on the slider section. The splines are not keyed.

3) Remove the metal strap from the slider boot nearer the center support. No need to remove the other strap. I used 2 zip ties to re-secure the boot.

4) Use duct tape to secure the u-joint caps. It resists the dragging on the concrete much better.

fiero2m4 · November 19, 2009

Is this the same clunk that a guy might hear when making a few consecutive shifts between reverse and drive, usually when making a 2 or 3 point turn? The clunk happens as soon as the transmission shifts, even with my foot still on the brake. Sounds like it's coming from the middle to rear part of the truck, like slack somewhere in the drivetrain...

I have the same noise / question. Is what 'mobiusdog' is describing what you guys are out to cure or some other scenario with a 'clunk'. Thanks for any additional insight.