Deerhunter4

Since Ford will not do anything to fix the horrible clunking that I get at every stop light, I decided to talk to a drive line shop. I told them I was willing to spend whatever I needed to fix this because it drives me insane. They said a new yoke will most likely not fix the clunking (FYI, I have a 1 piece drive shaft where the yoke connects to the transfer case). They said grease is about the only good option for now. They said that GM and some other have starting using nickel plated yokes to solve this problem but that Ford has not as far as they knew. They told me to use a heavy synthetic grease (which I have done 3 times so far and it works for a few hundred miles before the clunk returns) on the splines. I got tired of removing, greasing, and reinstalling the drive shaft (which takes me about 15 minutes now) so I decided to install a grease fitting to make my weekly greasing much easier. All that is required is drilling a hole about .75 inches from the rear part of the yoke, tapping the hole, and screwing in the fitting. Took me about 15 minutes and it works great. Now I can grease the yoke in a few seconds. The only issue is you have to move the truck until the fitting faces down so that it is accessible when you want to grease it. I took the truck on a 200 mile trip today (some 4 wheeling included) with no ill effects.

This isn't really a fix, but it is better than removing the drive shaft every time I fill up with gas. Just thought I would share and hopefully help someone else out.

TwinTurboFx4

Thumbs up

bubbabud

I did the same thing on my 4x2 with the 2 piece drive shaft at the slip spline on the rear shaft just behind the midshift bearing so far just greased it once 3000 miles no more thump clunk

ji603

I would be interested in pics. My old truck used to have an axlewrap clunk, and it had a zerk on the driveshaft. Three squirts, and she was good for another few K.

Kinda disappointed that ford claims there are no greasable zerks needed on the chassis.

Did you have to bevel the inside of the fitting where it extends into the shaft, or did you not thread it that far????

bubbabud

The mod I did on the 2piece shaft I drilled and tapped the slip sleeve ahead of where the internal shaft slides under full compresion so even if the zerk went in past the spline it still would not hit it. this is just like the old school or hd truck slip yokes. the grease is injected in the cavity in front of the spline and as the shaft spins it is forced to the outside of the cavity by centifugal force and is forced down the length of the spline by the shaft moving in and out with suspension movment. Since the spline is coverd by a plastic bellows you dont want to over grease it and blow out the bellows. I figure one or two squirts as needed should do the trick. so far 3000mi no klunk

Deerhunter4

I'll try to get one tonight. The fitting doesn't thread all the way through the yoke. I made sure to put it far enough back on the yoke so that even at max travel the output shaft would not impact the fitting if it did protrude on the inside.

Deerhunter4

I pumped mine full of grease. The one piece design doesn't use the bellows so I don't think you can use too much on it.

bubbabud

No but keep in mind all that grease will eventualy end up in the transfer case and contaminate the oil The designe of the single shaft spline is supposed to be lubed by the transfercase oil and should not need any further lube. I believe that the tolerances are loose on the ford spline and they just dont want to deal with it. Maby some one in the future will come up with a slipyoke eliminater kit like the after mkt has been installing on Jeeps for years

Deerhunter4

I thought about that but wasn't sure any would make it past the shaft seal. Guess ill have to change transfer case fluid sooner than expected. Looks easy enough to do.

Jimbo45

Exactly. I wouldn't want to pump grease into the trans case on a regular basis. That cant be good, and you may end up with a more expensive problem than just a "clunk", somewhere down the road.