After coming to a stop, I grew tired of the "thunk" I would get upon letting off the brakes. Felt like someone lightly rear-ended me. I always suspected a binding slip yoke. The slip yoke refused to accept any more grease so I figured the vent hole was clogged. After removing the drive shaft, I was amazed at how difficult the slip yoke was to get apart due to vacuum. After throughly cleaning everything I discovered there ain't no vent hole on this puppy. When I went to reassemble the yoke back onto the splines it would not slide/compress on the shaft due to trapped air. The seal works really well and even holding pressure on the yoke it would not "bleed down". Great, the drive shaft is now too long to reinstall. I ended up temporarily removing the slip yoke grease fitting and this gave all the trapped air and grease somewhere to escape when I pushed the yoke all the way back on the shaft. I reinstalled the front part of the drive shaft and then positioned the rear part so that as I pumped the slip yoke full of grease, it would extend into place. This ensured no trapped air and nuthin' but grease.

After driving now for almost a month the "thunk" seems to be gone. So anyone else experiencing this problem might want to give this a try. Make sure to mark the flanges and slip yoke with a chisel so that you can reassemble the shaft in the proper configuration. The bolts are pretty tight and required a wack on the box end wrench with a hammer (no room for sockets) to loosen.

 

Maj,
That's a good write-up. I've often wondered whether or not it has a vent/weep hole. I get the thunk as well, but it seems to subside slightly when I grease everything.

Hmm. Take another grease nipple, drill out the innards, and leave that in place as a vent until it's time to grease again.....

Andreas

 

aowRS,

Don't think that would do ya much good. The problem is that its tough to inject any new grease 'cause there ain't nowhere for air and the old grease to go. Most are vented through a hole in the middle of the yoke or one drilled in the tube. I pondered drilling one in the tube but obsessed over weakening the tube and drilling in the center of the hardened yoke (the best spot IMHO) was not in my game plan for the day.

 

This is actually a very good thread. Great job Maj!!

I never have had a warm fuzzy feeling after lubing my rear slip joint... Now when the day comes that feel like "really getting into it", I will do what you have done and make sure it is filled properly with new grease instead of just guessing and hoping.

Thanks again.

James

 

delete

 

Nice write up, I'll add this to my to do list.

 

Nature of the beast...although it would be worth tring.

 

too much trouble for me. ill take the thump lol... good write up though! makes good sense too

 

I was getting the same "clunk" right before I accelerated after letting off the brake. I recently took the truck to the dealer to have it serviced and I made sure to ask them to lube the driveshaft and other fittings. The "clunk" has now started happening as I slow down just right before I come to a complete stop. No longer on takeoff!! This "clunk" issue just tripps me out!! Dealer tried to act like it was normal....I think its a toyota conspiracy...