1989 Toyota 1/2 Ton, 22R 4 Speed driveline vibration

Is this lifted truck running higher driveshaft angles?

----------------- TheSnoMan.com

No lift on this

It's a 2wd, everything is stock - I have a 325lb wildernest camper on it at the moment and the springs are sagging a bit (I'm putting a pair of supersprings on it this evening)

-a SnoMan wrote:

I'm assuming that you scribed the driveshaft so that you could reinstall the same way it came out?

If not, that could be where your problem lies. You could experiment with resetting the u-joints in new configurations (one at a time, please) & see if that eliminates your vibration.

BTW there should be no detectable side to side play where your driveshaft is splined to your transmission. If so, you'll want to replace the splined portion of the driveshaft and hope that this cures it.

-- Mike Harris Austin, TX

Can't say for sure - I had a shop do it - limited toolset here :(

balancing the driveshaft would have the same effect yes?

Assuming that side to side play is the same as up and down in this case right?

Thanks

-a

So... is there a particular reason why you aren't having the shop at least try to fix it?

Not necessarily, unless they balanced it while on the vehicle.

Correct - and assuming that it is truly play between your transmission and the driveshaft and not the whole tailpiece of the transmission moving up and down on a loose or broken transmission mount.

-- Mike Harris Austin, TX

I was going to do it myself but I couldn't get the joint out so I took the driveshaft itself to the shop and reinstalled it myself

Not sure how keen they'll be on diagnosing the problem now..

I'll check the mounts tonight and if they look good I'll take it to a transmission/driveline shop tomorrow

Thanks

-a

Okay, my take on this is drive shaft joint angles. WHith age on load the springs settle and twist a bit from input torque and change drive driveline angle and Ujoints are constant velocity. You need to make sure angle are the same on both ends of driveshaft for starters. (the reason it does it is one gear at 40 and not another is because the lower gear can apply more drive shaft torque which can wind springs up more and change u joint angle more on rear axle connection. You might also pull drive shaft and have it rebalanced if everytighing else checks out. (Note, the rear joint should be tipped down with a bit more angel that front when static because it will tend to rise when torque is applied.

----------------- TheSnoMan.com

Okay... that explains a lot...

Back to my original question - did YOU scribe or otherwise mark your driveshaft so that you could reinstall it in the same orientation that you removed it, not 180 degrees out at the rear? Did you reinstall it properly? Cups centered in the rear yoke? No dirt, rocks, twigs or wooly mammoth in the yoke which might have interfered with the cups seating properly in the yoke? The joint itself is properly lubed with all needle bearings in place? All lock washers present and accounted for?

And... just to play Captain Obvious for a minute - did the vibration exist BEFORE you changed your u-joints? Was there a specific problem that you wanted to remedy or were you doing it "on spec?"

-- Mike Harris Austin, TX

So I could rotate the installation of the shaft itself by 180 degrees to see if the vibration disappears...

I didn't think of that - so no, I didn't mark the driveshaft in relation to the vehicle - I'll try that tonight

I'm assuming that the joint is properly installed with all needle bearings in place ( the shop did this)

I'll give the clips a visual to make sure all 8 of them are there

No worries on playing captain obvious - a different set of eyes on an existing problem always helps..

There was a vibration before - it's gone but a different one is there now

I could drive the truck at 80 before (with the bad ujoint) but I can't now - different, new vibration in the driveline

-a

Unless there is a slip yoke in the driveshaft itself allowing you to take it apart and get it the two halfs out of sync, you cannot put it on wrong.

----------------- TheSnoMan.com

There is no slip yoke on the driveshaft except for where it mates to the transmission.

The Transmission end of the driveshaft is splined to mate with the transmission.

that portion of the ds is about 6 inches long (roughly) and then the first u-joint, then the ds, then the second ujoint and the diff.

so there is no 'incorrect' way to mount a driveshaft like this?

Is it possible that the new ujoints 'unbalanced' the ds? and if so is the only solution to balance the driveshaft on the vehicle?

I had some ds's fabbed for an old land rover project I had and they were balanced at fabrication and I never had an issue like this with them..

-a SnoMan wrote:

Check ol the Ujoint angle with a protector if you can because if they are not correct to cancle each other out (because Ujoints are not constant velocity) it can cause vibration

----------------- TheSnoMan.com

Did you put the drive shaft back together properly?

Look at the "spokes" on the U-Joints, they should be aligned with each other. That is, the yokes on each end of the driveshaft must be in alignment. If the driveshaft has a slip joint in it, then it is possible for you to separate the slip joint, then not orientate the halves of the driveshaft when you put the slip joint back together.

Another possibility is that the driveshaft is out of balance. It is balanced at the factory, and when you come along and take the shaft off, you're supposed to mark all of the connection points, then put the shaft back in with the connections all orientated exactly the same way. If you do not orientate all of the connection points (places where parts bolt or otherwise fit together), then the balance of the driveline can be compromised, and a vibration can result.

But SnoMan, he had the same loading before he did the U-joint project. Id did not vibrate before, therefore the work he did must play a role in the new vibrations.

Yes and no. When it is on the verge of doing it, sometime a small change in joint tightness can change outcome

----------------- TheSnoMan.com