Well guys, guess what. I'm still battling this vibration problem on the interstate. As mentioned in numerous posts, I only get it when I get above 60-65 mph. Doing 75 mph on the interstate, the interior is vibrating like crazy. I don't know what to do at this point. Andy (Bamachem) checked underneath about two months ago and could not find anything wrong at all. It's been looked at by the dealer twice and they could not find anything that could be causing the vibration. It's been balanced god knows how many times. The last time I thought it was cured. I stood there the entire time and watched the guy and he was extremely meticulious about what he was doing (re-mounting the tire several times on the Hunter machine to make sure it was exactly right) and according to him, they were perfectly balanced when I left and I believe him. I think there is another root cause here. Remember I had the same awful vibration when I had my new set of Revos. Well, I thought it was the Revos so I returned them and dropped all that money on a set of Michelin Cross Terrains and I've still got a vibration. The only common link here is that before this go round with new tires, I was running the stock size 265/70/16. I'm now running 265/75/16. Could this cause the vibration? Could worn out shocks an struts cause the vibration? I'm at a total loss at this point because I don't know what else to do. All of my whining about a harsh ride is probably more so the fact that the truck shakes me to death on the interstate than it is the fact that it nearly throws me out of my seat when I hit a pothole. ANY, and I mean ANY, input on this would be greatly appreciated. Thanks guys.

Matt

 

have you had the alignment (toe) checked at all other than the one time at the firestone dealer?

what about cross rotating the tires every 5k - 7k miles?

 

Yes, worn out shocks can indeed cause this. But so can a lot of things. Check it all.

 

do you think it could be the brush guard? If it only has 2 mounting points, its more likely to wobble. I only have 2 mounting points on my shopping cart guard and it wobbles on the highway.

 

Andy,
The alignment was redone this past weekend. I get it aligned every time I get the oil changed. I just don't think it's an alignment issue. Also, I have been cross rating the tires at this same time and that has indeed been every 6k miles or there abouts. I don't know what's up. It's definitely not the brush guard because it was doing this before I had it. Like I said, the only common denominator here is the fact that both new sets of tires (Revos and the Cross Terrains) are 265/75/16 instead of the stock sized 265/70/16 but I just don't see how that can introduce so much vibration. Maybe my Toyota is just a freakin lemon and it's taken me this long to figure it out. Jeff Johnson, the service manager at Limbaugh Toyota, has checked it out twice and found nothing that would be causing the vibration. I trust him and believe what he says. Andy you even looked at it and couldn't find anything. I don't know what's up, but it driving me nuts!!!!!

Matt

 

It could be the shocks, but that can be easily checked by merely pushing down on all four corners of your ride and checking the recoil of the shocks.
If they rebound quickly and without bouncing, then they're good.
Have you had any leaks lately, i.e., PS ?!? If so, that could cause the shock to seize up on it's piston shaft or collaspe, as it were, but this would be evident upon visual examination in that there would be a good length of the piston rod sticking out of the top of the upper shock housing where it meets the upper "A" arm.
If you've not had a leak and since it is an '01, I'd venture to say that it was'nt the shocks and would look elsewhere, say, for instance the drive shaft/universal joints..., sometimes one of the joint cups (what actually holds the universal joint in place) can break inside of one of the "ears" and that's not immediately obvious upon inspection unless you jack the body of the vehicle up, letting the suspension "hang", so that you can manually actuate (by hand) the driveline to check for just this.
It's worth a shot.

 

Flamedx4,
Define "check it all?"

Matt

 

Ok, just did the home-made shock test.....

1. Rear of vehicle--Jumped up and down on the hitch and got the truck rocking pretty good and then got off and it stopped after three cycles. The second rebound being shorter than the first and the third being shorter than the second.
2. Driver's side front--Rocked the vehicle using the brush guard. Same response as above.
3. Passenger's side front--Rocked the vehicle using the brush guard. Same response as above.

Thoughts?

Matt

 

Here is a few to check that comes to mind:
Steering: is there any play
Strut bushings: are they worm out
Driveline: is the drive shaft balanced

 

Go to second part of my post (about the "driveline").

 

I had the dealer check the drive shaft u bolts and he said they were fine. He also said that if the drive shaft was not balanced, that I'd feel the vibration at all speeds and not just highway speeds. He didn't think that was the problem.

Matt

 

Either the driveshaft - or - you've got a bad rim (out of balance or warped)/tire (a broken belt), although the "tire" diagnosis seems to rule itself out as you've changed rubber all around (unless you got both sets at the same place), so I'd lean more towards the rim and think that you should have someone else check it all out instead of the same place as "two heads are better than one" and opinions are free.

 

Well,
The run out has been checked on the rims every time they were balanced and/or road force balanced on a Hunter machine and they have been balanced at three different places using the Hunter machine and Haweka adapter plate and noone said anything about an out of round wheel. So.......what next?

Matt

 

How about Roadtripr's advice and add suspension bushings to that list (on either end of the swaybars/endlinks).
It's called "Process of Elimination", we'll get it eventually.

 

Reagarding the steering issues I would check if the rack is loose due to worn bushings or if steering rack itself has problems. See this thread:
https://www.yotatech.com/forums/show...eering+problem

 

really don't think it's the shocks. i just replaced my shocks at ovet 200k and get this... they were the orignal shocks they were rusted through you can push um in and they don't come back out. anyway she rode fine at 90mph

 

Like I've mentioned, this didn't really start until I got the bigger tires when my Bridgestone H/Ls wore out. They were 265/70/16. Of course I did get them balanced periodically when I started getting some vibration and I seem to remember always having a little bit, but nothing to this extent. As a matter of fact, I remember I would always get a quickie re-balance on the Hunter machine right before a road trip to Baton Rouge for a football game to ensure a vibration free ride. Like I said, it was never perfect, but way way better than it is now. I just don't see how that small of a difference in tire size would make such a difference.

Matt

 

Did what I described earlier sound like normal shock rebound or was it excessive? Didn't really seem so to me, but if I knew I wouldn't be on here bugging ya'll.

Matt

 

The tire size would'nt make any difference to the ride quality, except that you might pick up more tire noise due to an emphasized tread pattern.
The only difference you would experience would be rubbing due to the increased height of the tire.
I've gone from the stock 31x10.50x15 to a 32x11.50x15 and all I've really experienced is the increase in tire noise, as I've mentioned before, which I sorta enjoy, actually.

 

Well, as I mentioned back when all this started, I had terrible vibration with the OEM Goodyear Wrangler RT/S P265/70 R 16's, from the day I drove off the lot.

The dealership tried rebalancing them numerous times to no avail.

I finally got disgusted with them, and traded the tires for some Michelin LTX M/S
LT265/75 R16 tires. They were a dramatic improvement, but they would go out-of-balance after several thousand miles. So I'd go back and have them re-balanced, and they would be good for another several thousand miles. Two of the tires were replaced under warranty due to an out-of-round condition that they developed.

I'm not convinced of Michelins supposed high quality.

I replaced those tires with Toyo Open Country A/T's in the same LT265/75 R16 size, and since they were mounted and balanced, they have been vibration free, approx. 25,000 miles. They've been rotated, but haven't required re-balancing.

I think your problem is still the tires.