Drive line noise/vibration

[mountainhick]

I searched and read quite a lot about the topic and am trying to take care of it prior to taking it to a drive line specialist.

The Previa has the TV 4x4 high low transfer case in and I swapped drive shafts in from the 92 donor van. These have 182K miles and I don;t know if they have been serviced, I suspect not.

It is also lifted. so drive shaft angles have changed.

The drive train is just a tiny bit more noisy than previously at all times, but there are a few situations where noise gets louder and even kind of scary:

-letting off gas/coasting in gear starts getting a little rough sounding


-at highway speed around 65 mph, scary rough growl with a rough vibration.


-I dropped out the rear axle and seems the u joints have no play but spline joint does. Not sure what is acceptable for this joint.


-Running without the rear axle on front wheel drive, it whines at higher speeds, and there is a notable clunk which sounds like up front when engaging the clutch especially from 1st to second gear. There is play when rotating the front shaft by hand at the front diff, Again, don't know if this is normal or acceptable.


-Also, there is play from the rear section of front shaft at the spline joint into transfer case. I checked the feel of the transfer case shaft before installing and it seemed fine, so suspect the spline joint from drive shaft may also have some slop


-There is movement at the carrier bearing that seems to be from the busing, not the bearing itself.


I'd like to drop out the front shaft and run it on the rear, but I don't have the tool to seal the front transfer case output shaft

It is also entirely possible that i re-assembled in some way that is not in proper alignment, for example, the manual says to match mark shafts to flanges when removed, but seemed moot transferring into a different Previa


Any thoughts would be highly appreciated


Ben

[timsrv]

Vibrations on all-wheel drive vehicles can be tough to track. It's largely trial and error. The 1st thing to do is determine frequency. High frequency vibes are usually driveline issues. Lower ones are usually tire/rim related. Does the frequency change with engine RPMs or does it consistently increase with road speed? If it changes with engine RPM I'd take a very close look at the SADS. If it increases with vehicle speed, then it's definitely drive train related. Removing parts of your drive system (like what you're doing with the drive lines) is a good way to rule certain things out. Just keep chipping away at it & you'll eventually get to the bottom of things.

I had similar issues with my Previa after lifting it & that's partly why I changed the drive angles by lowering my front differential and rotating my rear axle. I replaced my rear drive shaft with a Power Train Industries shaft, replaced my front most drive shaft with a new Toyota shaft, and took the other front shaft with hanger bearing down to a driveline shop to have removable u-joints installed and to have it balanced. I changed the SADS flex couplers & even swapped in a salvage yard front differential as I was suspicious of that too. Everything I did seemed to help a little and with mine I think it was multiple small things that added up to the bigger problem (no one thing seemed to be the smoking gun). In the end I got things running pretty smooth, but then the torque converter started vibrating when shifting from 3rd to fourth and down shifting from 4th to 3rd. That vibration isn't severe and it only lasts for a second or so during the shift. I decided to wait until it got worse before doing anything about it & so far it's been staying about the same. At least you don't have a torque converter to worry about anymore. Good luck. Tim

PS: If you're wanting to do everything yourself and not spend a fortune on new parts, there's a crude way of balancing your own shafts with hose clamps. Burntboot outlines the process HERE (http://www.toyotavantech.com/forum/showthread.php?650-Drive-shaft-balancing)

[mountainhick]

Thanks Tim,

Sounds/vibrations are entirely affected by road speed, I am sure not SADS.

I stumbled onto some of your info about your drive shafts after the lift, but it didn't register to me that you essentially replaced/serviced the entire line! It makes sense that we end up with problems after changing drive line angles from lifting.

I did lower the front differential, but I have not extended the rear axle upper control arms as of yet. The rear shock extension situation is a story unto itself which I did not do the same way as you since the lower end has metric thread, and I could not find any matching coupling nuts, so I made upper extension brackets off the crossmember. It is working for now, but it needs to be tweaked. Once I do that I'll probably adjust the rear axle angle.

The other aspect for me is since the auto transmission uses different shaft lengths, I also transplanted two of three shafts (the two outputs from transfer case, not the the front most shaft) from the donor into this van along with manual trans. As such the front pair may not be well matched/balanced as a set, and at the time I did not know about having to align them in phase. I don;t know if I did or not, it's a 50% possibility!

I have the drive shafts all out now and found a few things that I could not tell on the vehicle. The carrier bearing is bad, one U-joint has a bit of play, and the other 4 have no perceptible play but are a little stiff, and two of them have the slightly sticking feeling of pre bearing failure.

I found the 17 video series on replacing staked joints, so am considering DIY, but am taking the set to a pro for a look today.

If I do end up DIY, one local guy said he has the carrier/center bearing assmlbly for $95, know of any other source for less?

And, sounds like you did not do the shaft work yourself Tim, but one pro shop guy on the phone said he'd have to do some "machine work" to allow the clips for new replaceable u-joints. Seems others have done this as DIY with just deburring, not actual machine work. I am a lttle confused about this.

And finally, Tim, all I have found local replacement shafts that are WAY too expensive, and just OEM style with staked joints. Do you remember what you paid for the power train industries shaft? EDIT: Never mind, I found your post about this in 2010: http://www.toyotavantech.com/forum/showthread.php?35-Drive-shafts-and-u-joints&highlight=drive+shaft

[timsrv]

I should temper those glowing "free advertisement" posts I made for PowerTrain Industries with a link to this thread: http://www.toyotavantech.com/forum/showthread.php?895-Vibration

Here's another related post: http://www.toyotavantech.com/forum/showthread.php?390-Re-91-Previa-Alltrac-drivelines

When it comes to checking u-joints by hand, anything other than completely smooth is bad. Any binding or stiff spots are a dead giveaway. When checking by hand the force you can exert is nothing compared to what the vehicle does, so it's easy to think a joint is tight when it's shot.

I've used these specialty u-joints before but never on a Toyota. The times I've used them the retainer clip areas did not require machine work, but it's entirely possible that the Toyota shafts do.

At the time I did my drive-shaft work, I could not find a new shaft w/carrier bearing (2nd one back for the front drive) so I got one from a salvage yard then had it reworked at a drive-line shop (while I continued using the old one). I don't think it's common for these carrier bearings to fail, so if you can't find a good deal on new, I'd go to a salvage yard and look for used. Sounds like you're well on your way to getting this all worked out. Tim

PS: I happen to have a new OEM front most shaft still in the box I'd let go for $150 + shipping. Just PM me if you're interested. Tim

[pdgizwiz]

A conventional U-joint is known as a Cardan joint or Hooke's (http://en.wikipedia.org/wiki/Universal_joint) joint.
If you have one joint between two shafts at some angle, and the input side is spinning at a constant rate of rotation, the output shafts rate of rotation won't be constant. If you scroll down in the wikipedia link above you'll see the math behind this phenomenon, and graphs on the right hand side that illustrate how the deviation increases with angle. The fix is the "double Cardan joint" which is how your stock driveshafts are designed. The effect cancels out if the joints on the intermediate shaft are clocked the same, and the input and output shafts are parallel to each other (are at the same angle with respect to the intermediate shaft). If you lift a car and don't take this into account, you might get some irritating vibrations.
The reason a "constant velocity" joint is called that is that they don't have this characteristic.

[TheMAN]

noise when coasting sounds like it is diff related... the backlash is probably out of whack.... this is typically due to bearing and gear wear in the diff you should pull the cover off and inspect for gear wear and rebuild the diff if necessary when you lifted the van, did you extend the panhard arm? not changing the panhard arm length will cause the rear axle to be off center... this may cause problems with the vehicle's tracking U joint vibrations won't be surprising if the van was lifted too much... new/good U-joints should reduce this effect

[mountainhick]

A conventional U-joint is known as a Cardan joint or Hooke's (http://en.wikipedia.org/wiki/Universal_joint) joint.
If you have one joint between two shafts at some angle, and the input side is spinning at a constant rate of rotation, the output shafts rate of rotation won't be constant. If you scroll down in the wikipedia link above you'll see the math behind this phenomenon, and graphs on the right hand side that illustrate how the deviation increases with angle. The fix is the "double Cardan joint" which is how your stock driveshafts are designed. The effect cancels out if the joints on the intermediate shaft are clocked the same, and the input and output shafts are parallel to each other (are at the same angle with respect to the intermediate shaft). If you lift a car and don't take this into account, you might get some irritating vibrations.
The reason a "constant velocity" joint is called that is that they don't have this characteristic.

Thanks.

Funny, I just discovered the angled drive shaft u-joint wave effect a couple days ago before you posted this. The front drive shaft is 2 piece as you describe. The lift itself does not create a change in the front driveshaft angles, but dropping the diff lower to achieve better front axle angles does. But the change in angle at that u-joint is miniscule. The graph you refer to shows the first line at 15 degree angle which is much much more in comparison. So point taken, but I suspect not the actual cause of the problem.

The center/carrier bearing was bad for sure and U joint at front transfer case output was rough feeling and seemed to have some play. And, the two shafts attached at the transfer were from the donor van, so front pair not necessarily matched and balanced. The driveline shop looked at the assembly, said the front part of the shaft still has good u joints. They are replacing carrier and u joint on the rear section and balancing the works. I should have this back tomorrow.

If some vibration in the front end remains, I'll consider the double cardan when the middle u-joint actually goes.

[mountainhick]

noise when coasting sounds like it is diff related... the backlash is probably out of whack.... this is typically due to bearing and gear wear in the diff you should pull the cover off and inspect for gear wear and rebuild the diff if necessary when you lifted the van, did you extend the panhard arm? not changing the panhard arm length will cause the rear axle to be off center... this may cause problems with the vehicle's tracking U joint vibrations won't be surprising if the van was lifted too much... new/good U-joints should reduce this effect


Thanks for the reply. I have not changed the panhard/upper control arm length yet. It is in the longer term plan if needed after the shafts are replaced. I still have to tweak the shock mount extension situation to allow room to rotate the axle.

All drive shafts are being rebuilt/replaced. I should have the front back tomorrow, and rear in a few more days.

There was a clunk going into low gears especially from 1st to 2nd when running only on the front axle/rear driveshaft removed. Might be the diff, but could have just been from the driveshaft play as well. I'll know soon!

[mountainhick]

Reworked shafts are in. The interstate is 1/2 hr away, so I haven't driven the bean at full highway speed yet, but took her for a test drive yesterday and definitely quieter.

But we did get snow, so I can try her out and see how the 4x4 transfer compares to AWD with viscous coupling.