Damn Vibration... Any suggestions appreciated!

[gottadiesel]

I’m feelin those “bad” vibrations…

Here is the scoop and this is what has already been done:

Current – High Frequency vibration at about 62-68, goes away to some degree around 70, comes back at about 75 or so and then as you near 80, start to also pick up this oscillating low freq vibration. All in car, none in steering wheel – it becomes obvious at night when the headlights in the rear view mirror all of a sudden look like 50 headlights moving up and down…

To begin with I could feel some in the wheel also, so did the obvious things, went and had wheel balance checked… Wheels and Tires have less than 5k on them. Slightly off, they re-balanced. Did not fix the issue, so went to another place in which they had a dynamic wheel balancer, in which of course I could only do the fronts of the car. But they did them and changed weights, vibration in wheel now gone… now I could still feel what I feel now in the car itself.

Now turned to the driveline, carrier seemed like it had too much play, pulled drive-line and took to drive-line shop, they replaced carrier and rear u-joint (was not loose, but a little stiff) then they balanced it. I put it back in, it was worse, way worse… took it back, they spent an hour with it, trying to get it to balance at both low, mid and high rpms… said they got it for sure, put it back in… it got a lot better, but it is still like what was described in the beginning.

Had rear wheel balance re-checked, all is good…

Side note – new engine and tranny mounts during build… Drive line does line up (so no slippage of the embedded rubber in 2nd half of shaft)

I am going to go back to the drive-line place for the 3rd time and see if they have any further thoughts… I am thinking it is now perhaps time to just go to a one piece steel, not sure…

Does anyone have any further thoughts as to what might cause such an issue?

 

[IJ.]

Out of phase driveshaft, sight along the UNI joints all 3 should be in line.

 

[Moy]

check your wheel bearings, the rears especially

 

[gottadiesel]

Out of phase driveshaft, sight along the UNI joints all 3 should be in line.

Side note – new engine and tranny mounts during build… Drive line does line up (so no slippage of the embedded rubber in 2nd half of shaft)

Thanks IJ, though I did check that, my wording was a little vague, but that is what I was referring to... I did that after reading the sticky in the transmission and drive-line section...

Maybe they just can't get balanced??? Though they come recommended by many, been in business for 30+ years, but seems like they do more heavy equipment, so perhaps the smaller higher-speed ones, perhaps have less experience... I was going to convert my engine rpms to what the drive-line is spinning at, so that I could see what their balancer says at those rpm speeds...

In your opinion, are there issues with going to a one piece, I know there are with aluminum, but what about a steel one? I just do not want to put anymore money in to this one, if it would be a better long run option to go to one piece...

 

[IJ.]

You'd need to do the calculations for critical speed on a steel 1 piece, I tend to stay away from them in general as my cars tend to rev quite hard and are driven at high speeds so a shaft failure is a huge concern.

 

[Poodles]

Rear section is bonded rubber, spinning it on a machine isn't the same as loading it on a car.

 

[gottadiesel]

check your wheel bearings, the rears especially

They sound and feel clean when spinning on jackstands... also no play any direction on rear or front... was just aligned a couple of weeks ago, so should be no issues with excessive play anywhere...

 

[IJ.]

Is there any change in vibration on/off throttle, clutch in/out?

 

[gottadiesel]

Rear section is bonded rubber, spinning it on a machine isn't the same as loading it on a car.

Yeah I was wondering about that myself, which is why I was debating getting rid of it and going to one-piece, but I see there are multiple concerns there also... I am thinking the rubber is 23 years old, it is probably not pliable and flexible as when it was new... Poddles - do you have thoughts on the best way to cure that in your opinion?

have the bonded section replaced with a straight tube making it a true 2 piece (this is what I've done in the past)

This was taken from Sticky... What did you mean by this? Let me re-phrase, I know the theory, I am curious of the specifics of the process you followed.

Thanks to all!

 

[IJ.]

I have the shop cut out the Tube in a tube bonded section and weld a tube in.

 

[gottadiesel]

Is there any change in vibration on/off throttle, clutch in/out?

There is no obvious difference between on/off throttle, almost seems the worst when you settle into a speed and throttle setting (cruise)... Less noticable to me during hard acceleration, but not sure if that is just because there is some much else happening at the same time or if it really minimizes it.

Clutch in/out tried that no difference, also tried sitting in N with clutch engaged and sat at the same RPMs with no weird vibrations...

---------- Post added at 01:47 PM ---------- Previous post was at 01:45 PM ----------

I have the shop cut out the Tube in a tube bonded section and weld a tube in.

Thanks for the pic... Ok, that makes sense...

 

[IJ.]

I get a bit serious about driveshafts, they have the potential to kill you if they fail at speed/load...

 

[gottadiesel]

^^ Better safe than sorry

So I spoke to the shop, I will take it in one more time, with information as to the actual rpms of the shaft... if their machine still says it is balanced at those rpms then they said they could do the tube replacement for $160, to rid it of the rubber composition...

We'll see what happens...

To all who responded - Thank you for all of the insight!

 

[gottadiesel]

There is no obvious difference between on/off throttle, almost seems the worst when you settle into a speed and throttle setting (cruise)... Less noticable to me during hard acceleration, but not sure if that is just because there is some much else happening at the same time or if it really minimizes it.

Clutch in/out tried that no difference, also tried sitting in N with clutch engaged and sat at the same RPMs with no weird vibrations...

I checked this a little closer on the road yesterday... for sure much of the vibration goes away during acceleration, little difference between decel and cruise though... again more of a high freq vibration, I tell the most by looking in my rear view mirror and see everything looking like I have two 14's with 2000 watts behind them playin some snoopdog

Anyway if there are further thoughts, they would be appreciated, otherwise I will be taking shaft in tomorrow to continue down the path of re-tubing it...

Thanks

 

[gottadiesel]

Update - Had rubber section removed and new tube welded in and re-balanced... took it for short test drive, but was foggy... felt good so far (crossing fingers) headed to a job site about 3 hrs away in the morning... guess I will know if it is all gone by the end of that ride...

Thanks again for all the responses... and thank you again IJ, I can add another IJ solution to my list of things that I have done based on your recommendation... and of course (no surprise on my part) they have all worked...:icon_bigg

IJ - Now looking at your pic that you sent again... looks like you were showing removing the front section, but your rear sections does not look original either... did you have both removed? The front is solid is it not, where I know the rear section is bonded? Just checking to see if I missed something... Thanks

 

[IJ.]

Only the rear is bonded, that was my custom shaft the only Toyota bit left is the Centre bearing.

 

[gottadiesel]

Only the rear is bonded, that was my custom shaft the only Toyota bit left is the Centre bearing.

Thanks for clarification, I did not see anyway that the front was anything but solid... but makes sense with your explanation.

One other question and looking at your shaft, I am making an assumption... but we all know what that does... I know the UNI are too all line up, but I am assuming that it is right for the front and rear to be 90 degrees out of sync (speaking of the portion of yoke attached to solid shaft... It is how mine is now and how yours is in your picture...

Long story short, it is a lot better, so I know the rubber was causing an issue, but I am not 100% satisfied yet, the high freq vibration is about all gone, but I still get this oscillation lower freq vibration, seems to perhaps start in the back and work its way forward... almost seems like a slow motion shiver. It is something I would expect if I have loose tie rod ends or something of that nature, but everything is tight.

But it only seems to happen at certain speeds and not bad enough to worry about driving it, so I will continue to try to isolate its origin.

Keep in mind this is something that more than 1/2 of anyone else would never notice... always been picky about smooth and no rattles... yeah I know what you are thinking... but no one can make fun of me as good as my wife can, so don't even try:icon_bigg

 

[IJ.]

As long as the Caps are in phase and it's balanced as an assembly it doesn't matter about the 90 out, Try this jack the back of the car up and put a stand or a jack under the lower control arm so the weight of the car is on the suspension and the wheel is off the ground.

Now grab the wheel and see if there is any wiggle side to side or diagonal.

 

[gottadiesel]

As long as the Caps are in phase and it's balanced as an assembly it doesn't matter about the 90 out, Try this jack the back of the car up and put a stand or a jack under the lower control arm so the weight of the car is on the suspension and the wheel is off the ground.

Now grab the wheel and see if there is any wiggle side to side or diagonal.

OK, I will try that, yeah I usually place stand at inside point of lower arm... I have not tried putting weight on suspension and checking for play but I see where you are going with it... will update this evening, my time that is

 

[gottadiesel]

Try this jack the back of the car up and put a stand or a jack under the lower control arm so the weight of the car is on the suspension and the wheel is off the ground.

Now grab the wheel and see if there is any wiggle side to side or diagonal.

Done today... So here is my findings, also checked lash closer... see below:

Nothing left to right or on the 45 degree, so I also used bar to leverage bar between concrete floor and tire to find any up and down movement, had helper leverage while I inspected below, no visible movement, when I do the leveraging myself I could feel an ever so slight movement (talking 1/64 maybe) in DS rear, but nothing on PS rear. Wheel feels clean when rotating by hand.

Lash is another story:

In N with E-brake set, I get slight movement at diff input (assume that would be pinion gear lash right?)
In reality I get quite a bit of lash but it is really at the inboard joint (either tripod or joint tulip) I have not had the rear end of a supra apart yet, so I am not sure what typically would be wearing to create that level of lash...

So to make sure I am clear, if I try to rotate the drive-line with E-brake one, it will rotate 3/16" to a 1/4" but if I hold the inboard tulip, I only get about 1/32" to 1/16" of lash in the pinion, but when I let go of inboard shaft, then I get the full lash, but drive shaft is not moving, only the tulip, so the outboard joint seems tight.

What would you expect to see for symptoms with the above findings?

Thanks again... appreciate your time, as I noticed on another thread you are pretty busy setting up shop at a new home... congrats by the way, I did not read the entire thread, so not sure why you ended up moving, but hope all goes well... I know the pains of it (at almost 40, I have moved 36 times...) Hopefully I am done...