Ok all, got a '90 2wd 'Runner Automatic with LC coils and BJ spacers. I'm on my second set of u-joints and the output bearing from the tranny in 65k miles. With new u-joints and a new bearing, I still have a mild vibration that I started with with the previous setup when at cruising speed or upon deceleration. I considered having the propeller (drive) shaft checked, but the local (and reputable) driveline shop said they won't touch this particular Toyota driveline because the of the rubber "harmonic balancer" on the inside. They told me to check with Toyota. They're discontinued...

So, I'm stuck at the moment and am not even sure it's the driveshaft that's the problem! Anything else I can try while I try to figure out this driveshaft thing???

Otherwise, I'll be changing ujoints and output bearings on a regular basis, driving with a vibration at cruising speeds and on deceleration.

 

you might want to jack up the rear and run it and see if the drive shaft is bent. by installing the lc coils did it change the angle of witch the u-joints don't like.

 

Had the pinion angles checked by the driveline shop AND Nick at Trail Gear. Both said their well within spec. It's really only a mild lift.

 

Check the angle yourself, it is trivial to do:
- http://www.4crawler.com/4x4/CheapTri...n-Measurements
A little more involved on a 2WD, you'll need an angle finder.

Have heard of even reputable shops checking alignment and saying it way good or bad, but they were using the wrong specs; for example assuming a CV shaft and finding the angles "wrong", but it was right for a u-joint shaft and vice versa.

Check the phasing at the same time (not sure if that can get out of whack on the 2WD shaft or not):
- http://www.4crawler.com/4x4/CheapTri....shtml#Phasing

And never heard of Toyota shaft with built in balancer, they may exist, but have never seen nor heard of one.

And check the output and pinon flange for play.

And if all else is OK, measure the overall shaft angle, I found that once you get above 12-15 degrees on a single-cardan shaft, that it'll not run smooth even if perfectly balanced and aligned.

 

Two wheel drive has a slip yoke at the end of the transmission output right? I'm not sure how important is it to balance with the slip yoke attached to the drive shaft.
One test you can do is to put the old springs back and see if you still get the vibe. If not, then it's the lift. I end up with a double cardan joint in the rear to get rid of vibration after I lift the rear with OME Land Cruiser 2.5" lift springs.

 

if it is a slip yoke you have to make sure that the shafts are in line once you put it back together otherwise it throws the driveline off balance

 

Roger: I'll read up on your "phasing" post this evening and check it. Appreciate your expertise! PS, Roger: It was Driveline Service of Fresno that told me my pinion was fine. Trail Gear seconded the opinion. I have to assume it's not that.

Anthony1: Don't have to old springs to test with... Tell me about the double cardan. Did you originally have a single shaft? If so, did you just have the double (cv) made?

Green_slime: The tranny shop did the pull/install. How would I check it after the fact?

Thanks a bunch for all the suggestions. It's much appreciated.

 

I used the front d-shaft from an 85 truck. The driveline shop lengthen and balanced it. Keep in mind that this is a 4wd with t-case and flange output. You would have to adopt it to fit the slip yoke.

 

Now, I asked the guy at the driveline shop about just building a new driveline. His response was that the rubber "balancer" thing in the Toyota driveshaft (of course, I'm assuming its the Toyota stocker) is there for a reason, get one from the dealer. As said before, Toyota discontinued them. So now what?

 

Rubber balancer? Man I wish the shop could be more specific, I've never even heard of one in a Toyota although my experience is limited. I know there are CV style DS's that you can buy but I don't believe they came factory on the 2wd models, could be wrong there. Can you pull a DS out of another Yota and bolt it in?

I'm leaning towards the input on the rear end being loose or worn a bit. Vibration on deceleration is usually a u-joint (yours of course are new) or something loose in the rear end, even heard of vibration caused by the DS being out of "phase" but am unsure what that entails. I think the yokes have to be lined up when you reinstall it to keep things balanced.

Can you zip outside and snap a photo of the DS showing both ends? That might help us, or at least me, see something wrong.


Edit: By balancer are they talking about a carrier bearing? I've never been under a 2wd so don't know if they have them or not.

Edit #2: Does it look like this?

 

Ya some pics would help for sure

 

I don't think you have it.
You may need to get adjustable upper links and tilt the rear diff up some. That should get rid of the vibration.


I have to do both ( adjustable link and double cardan joint). This is an old pic of the diff...yes, it leaked. I've fixed it since then...



If you're thinking about double cardan joint, you can do it by removing the end of the joint and mate ti to the slip yoke. Any drive line shop can do that for you. Look for the manual on the sticky section and take a look at the difference between 2wd and 4wd d-shaft. You'll see what I mean.

 

which u-joint(s) are failing?

90 2wd should be a prop shaft to a carrier bearing and then CV joint at the top/frame and then u-joint at the diff.... unless I'm missing something.

 

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Less than 500 miles and the seal at the output of the tranny is already developing a leak. Pisses me off.

 

Don't know if those photos were taken at the same time (w/o moving the vehicle in between) and hard to tell from the viewing angles, but does not look like the u-joints are aligned (phased - should line up like the light blue line below):

 

Snapped at the same time, Roger. Should I get wrenching and line 'em up?

 

If they don't line up end to end, then looks like the shaft may have been built wrong or perhaps was modified at some time and not lined up properly. Since the slip splines are not in the center of the shaft (like on the 4WD models), no easy way to separate it to line up the ends.

To check, see if you can roll the truck until the end caps of one u-joint is horizontal then see if the other end is also horizontal or not.

 

K, checked for lineup, and it appears that the joints are lined up. Check that one off the list. Now what?

 

OK, just could not see the phasing/alignment in the photos. Well, 2 or 3 things can cause vibration, alignment of the u-joint angles (should be equal to each other), the balance of the shaft and then any play at either end.

 

Both pinions need to sit parallel.