Vibration at Speed...U-Joint?

[Kanger328]

Hello All,
I've been a lurker for awhile, but just picked up a new-to-me Runner today. I will do a complete introduction with lots of pics tomorrow after I have a chance to clean it up.

But for now...I noticed a vibration at 60-70 mph whether under acceleration or coasting. I searched on this forum and found it is most likely the rear u-joint, but when I check it for free play, it doesn't move at all. I moved up to the u-joint at the transmission end and that does move around a bit, so I'm wondering if this is the issue or if this is normal. I did read a post about a member who did not have free play in the rear u-joint, but still replaced it to fix the vibration problem.

Advice from the veterans please. Thanks in advance! And as promised, proper intro soon.

 

[downpour11]

Try greasing the ujoints first. It solved my problem for a bit. I use Mystik No. 2 Hi-Temp grease.
But yes, that loose one could be your problem.

 

[ToyOtis]

I had the horrible vibration at that speed too. Rear joint was not loose, in fact it was nearly seized. Only way to tell was to drop the rear of the shaft. Joint would move smoothly in one direction, and almost nothing in the other.

After I disassembled it, mine looked like this.



3 points were perfect. The 4th was rusted and no lube would get to it.
Still had a little vibration after I replaced the rear u joint, so I took it to a local driveline place and they balanced it. Smooth as silk now. (My double cardan checked out ok)

 

[Kanger328]

Thanks guys!

ToyOtis: Do you by any chance know the part # for this? This is the part I found on RockAuto...would like to confirm it's the right one. It's a MOOG #285
More Information for MOOG/PRECISION 285

 

[ToyOtis]

My local NAPA sold me a Precision/Federal Mogul #387. It was the only place I could get to that day and I had to get it done. It fit fine.

My runner is an '02. Not sure if my part # will fit your '96, sorry.

 

[ToyOtis]

Driveshaft Removal

Use some PB or Liquid Wrench type product on the nuts and flanges first and let soak.

On the double cardan end
On my '02, there are 4 nuts to remove on the driveshaft side of the transfer case flange. The studs will stay in the transfer case flange. Just remove the nuts. I ended up using two box end wrenches linked together for better leverage. In my case, there was also some rust bonding the flanges together. And a raised ring (as seen at the very right end of the stolen photo below) that keeps everything centered. I had to use the sharp edge of a painters 5in1 tool and a hammer to break the rust bond at the flange.

 

[ToyOtis]

Driveshaft Removal

The ujoint (rear) end of the shaft is attached with four bolts and nuts. Again, be sure to hit it with PB or Liquid Wrench first. I also had to pry this end loose too.
The rear flange has the centering ring as well, so the whole shaft needs to be squeezed shorter or the rear axle dropped a bit to get it out.

Since I had recently lubed the shaft and the slip yoke was full of grease, the shaft would not compress enough to allow me to remove it. I just unscrewed the zerk on the yoke, crawled out from underneath, stepped on the rear bumper a couple times and enough grease shot out of the zerk hole to allow me to pull the shaft out. (Just make sure your tools and creeper are out of the line of fire! Don't ask me how I know...)

I was working under the truck with the rear wheels up on ramps. I didn't have my jack stands with me, so this was my best option at the time. I'm sure there are easier ways to do this.

Good luck and let us know how you make out!

 

[Kanger328]

Well, I just got it fixed! Turns out it was a bolt or nut that was missing in the yoke on the trans end of the rear driveshaft? I don't know, that's what the mechanic said. The u-joints are fine apparently. Luckily, the mechanic as a family friend and he fixed it for FREE. No more vibrations! Thanks for all the help fellas!