drive shaft issues

Hi just a follow up to an earlier post concerning clunking in the drive train. It was suggested to repack the yoke in the shaft with grease. I did and it appears to have corrected the problem. Pass it on. Thanks for the help! Bill

 

This is the slip joint near the back? I have a zerk there and put some grease in it. With each pump of my grease gun the joint slipped a little so I stopped. Should I have pumped until I saw grease squishing out?

 

I think instruction says to put just 2-3 pumps. If you fill up the whole space with grease you will hydrolock the joint.

 

Hi I never saw anyplace that said how many pumps of grease goes into the yoke. Toyota told me to clean out the yoke and put a light coat of grease on the spline. That did not work it only got worse. I do know after filling and driving easy excess grease did come out of the joint. I hope it just works itself to a happy place. I think what caused my problem was carrying my truck camper. The extra weight compressed the shaft and forced the grease out to create a cavity. That void made an air pocket that would get stuck. Bill

 

If you have a two piece driveshaft , reports are coming in there is a lack of lubricant on the splines of the slip and stub . Your truck will clunk when downshifting into first gear when cold . Takes a special lubricant
This stuff will work http://www.lowrangeoffroad.com/ptfe...-ford-motorcraft-xg-8-ml1167-31508-42027.html
And this stuff is said to be the best but pricey http://paceperformance.com/i-782162...bricant-high-temperature-c1-2-w-a-t-1-lb.html

The splines on your slip yokes are not designed to use grease .
They are designed to use glide-coat , and a high wear teflon based lubricant .
The lubricant is expensive as you can see in the above links and probably why Spicer doesnt add much to the splines on every toyota truck sold .. The teflon lubricant is resistant to coming off the splines and getting forced out the end of the yoke . You are essentailly replacing a coating of graphite that has worn off the splines when you add this lubricant .

 

What do you do? Take it apart, clean it up and lube it, then put it back together?

 

Yes . Thats the best way to tackle the slip yoke . Not only that , but you also check your universal joints properly when the driveshaft is removed

 

I've got a couple videos for you dudes on this subject. Taking the slip yoke off and greasing it with a special grease has helped my rear end clunking but it doesn't last as long as I wish it would. I think the reason why a lot of us have issues is the zerk fitting for the slip yoke does a horrible job of lubricating the splines. Most of the grease just ends up packed at the bottom of the yoke. Over time due to the poor lubrication, excessive wear occurs and not even proper lubrication will completely fix the clunking issue. I can grab the main driveshaft and slip yoke twisting them in opposite directions and there's a decent amount of play in the splines. When I check my front drive shaft and slip yoke, there's no detectable play. The play in the rear shaft could be normal because it's always turning while we drive but something tells me the play wouldn't have been as bad if the yoke was properly lubricated over the years.

I made two videos. The first is the primary one and the second is me trying out the new grease. The special Ford grease definitely helps. My slip yoke barely clunks after the greasing but it starts getting worse in a few thousand miles and I need to do it again. The greasing use to keep the clunking away for around 10,000 miles but I think the spline wear has gotten worse and that's why I've been forced to do it more frequently. I think I might just break down at some point and get a custom driveshaft from someplace like Tom Woods.

Ok, enough typing. Here's the videos:

https://www.youtube.com/embed/oKX5UeE2Txs

https://www.youtube.com/embed/Jyltxe2nPEg

 

Has anyone taken the slip joint apart and not marked it and put it together again differently than it had come out? If so did you get any vibes that weren't there before? I got a good deal on one, but the slip joint had been separated. Wondering if it's worth getting balanced. Might just end up being my trail replacement.

 

From what I've read, the main propeller shaft and slip yoke are balanced in the same orientation so you can get it very close. Take a look at the one currently on your truck and you'll see the u-joints of the double cardan joint near the transfer case line up with the u-joint at the rear differential. I'd lay it on the ground and keep repositioning the slip yoke until the u-joints line up just like the one on your rig where everything matches, even the direction the zerk fittings face. If you do that, your shaft will be very close to being balanced, if not perfectly balanced. You could even test it out by pulling your current one and putting that one in and taking it for a test drive. I'd take it on surface streets first. if you don't detect any weird vibrations, take it for a spin at freeway speeds. If everything seems good, take a paint pen or other marker and make match marks on the main propeller shaft and ship yoke so you'll know how it goes back together the next time.

 

Thanks man. Good common sense info - I'll try it when he brings the slip yoke over - it was still bolted up to the diff and we didn't feel like taking it off without an impact that day.

 

Just one spline off is visually very obvious when compared to how it should be. The spline count is low so just one off is obvious. While they are balanced as a unit, the separate "halves" are still in balance and countless folks have swapped "halves" with other shafts with no vibration issues. Many folks carry just the rear half as a trail spare.
Also note that if aftermarket u-joints have been installed, the kind with the zerks in the caps, who knows what orientation was used at assembly. In that case go with the yoke orientation from the drawing and test drive. Worst case, one or more of the joints is 180 deg out.




There is a catch 22 with the grease fitting for the slip joint. The cavity at the end of the inside shaft is between the fitting and the splines. Therefore it is impossible to get grease to the splines without first filling up the cavity. Now if the cavity is full of grease, the first good "slip" of the joint can hydraulically pop out the core plug at the end of the yoke. Of course this depends on the condition of the joint, it's seal and if there are any air "bubbles" in the cavity. Been there.
It's kind of a bad deal but it is what it is.
The DC joint actually has a crude pressure relief valve. This prevents the centering ball from being hydraulically pressed out of position by pressure from a grease gun.
When I occasionally use the slip joint zerk to "freshen" things up, I slowly bounce the rear of the truck up and down (with my weight, after greasing) a few times. Some folks go for a short drive or do the bounce with the zerk removed to get a little air cushion in there.


Core plug in question.

 

This is why pulling the slip yoke out and manually greasing it is the best way to go in my opinion. Even if you fill the yoke with grease, the upper splines are still not getting lubricated because the yoke and propeller shaft would have to separate very far to draw grease to the upper splines and I don't think it's possible for the shaft to separate that far unless there's some excessive movement in your drivetrain.

 

Yep and by the same logic, a u-joint is not really greased until grease comes out all 4 cap seals. Many times a joint will need to be flexed a bit (off the truck) to get this to happen.
I do a "remove and lube/check" around every 4 or 5 "on the truck" lubes. I have to remove the shaft to manually grease the DC joint as it is, due to a modification.

 

That's good to know about the u-joints. I usually stop when I see it squirting pretty good out of at least a couple of the caps but I'll pay more attention next time I grease the u-joints.

 

Wow, all the 'heavies' are in this thread. Nice job OP.

 

All good greasing suggestions.^^

 

Hi when I filled my yoke using the grease fitting I had excess grease come out of the spline and spun onto my muffler. I unknowingly over filled it. I will check the rear plug. I didn't notice any issues. Thanks for all the input from all. Bill

 

You don't happen to play guitar in a three piece band do you? Or have a long gray beard?

 

Does any one thing will be a good idea to remove the zerk drive for a bit and then pump some grease after?