hard shaking/vibration at highway speeds

[mx52nr]

Ok here's my situation... At 60-70mph (iirc 2500 rpm in 5th) there's a low resonance vibration throughout the cabin, at 70-80mph (iirc 3k rpm in 5th) it gets a bit more high pitched. It only happens when I accelerate. It is really bad at 2-2500 rpm, it sounds like a low resonance sub - it literally shakes the dash, and all the interior panels; the seats have a really harsh vibration. It's unbelievably unpleasant on a long trip...

I'm thinking it could be exhaust related after looking under it and seeing a loose bracket just before the cat. I'm guessing I would need to get a muffler shop to bend me some new pipes? I bought the truck about 18 months ago, and I doubt the exhaust/cat/muffler has ever been changed from the looks of it... Anyone have a similar situation? Any help is really appreciated!

BTW - my truck is a '96 4cyl manual 4x4 with 177k...


thanks!

 

[Ill4Runner]

When was the last time your tires were balanced or you had an alignment?

 

[240K'97T4R]

I have the same problem. When I hit about 55mph and on the steering wheel would vibrate from side to side. The dash shook a little bit but it is mostly the wheel. I did some research and it sounds like it can be from bent or warped rotors. It sounds like it is a pretty common problem and there are a couple threads on it if you try to search for them. I have a '97 SR5 with 242K miles on it. I haven't gotten the rotors checked but it might be your problem also.

 

[mx52nr]

When was the last time your tires were balanced or you had an alignment?

The tires were rotated and balanced about 2 weeks ago, about a week before the shaking started... The truck drives straight, although I haven't had an alignment done in a while... Initially, I thought the alignment could be the problem, but it only happens on acceleration, when I coast it goes away....



240K'97T4R, I had new rotors installed almost 9 months ago (about 10k miles ago)... Could the rotors get warped that badly that soon?


I removed the dangling bracket/clamp and drove the truck today at similar speeds, it didn't seem as bad as it was the other day, but there was still a slight vibration when I accelerated. It also seemed a bit sluggish on acceleration.


I consulted a car-buddy of mine, he suggested checking out the catalytic converter. He said it might be blocked from deterioration. Do you guys think that might be the issue?


Thanks again for responding guys....

 

[Ron Helmuth]

Shaking thru the steering wheel?

No I do not think anything you have described would have anything to do with a clogged catalytic converter-that would show itself as a lack of power, sluggish acceleration and so on.

Are you feeling the shaking in the steering wheel ? If so I would have your tie rod ends checked, it only takes a slight amount of excess play to cause the front tires to shake-and generally at higher speeds as opposed to cruising around town speeds.

I will take a wild guess and say something in the driveline-like an out of balance driveshaft or loose connection where it attaches to the differential...

I am not mechanically inclined myself-I would have your alignment shop drive it while you ride along, this is one reason I use Firestone as they sell "lifetime alignments" so once paid for you can get your money's worth out of them.

Stay in touch so we can all learn from this please.

 

[mliebal]

Good luck
Mike

 

[neo mrosko]

if it's tire balance it should vibrate on coasting and accleration but you should recheck the Tire balance...

I'm extremely gratefull for this guys web site
http://www.gadgetonline.com/Vibration.htm


I've had the experience that very few tire dealers, etc., actually know how to properly balance lug centric hubs like those on toyota and they'll try to convince you there's something wrong with your vehicle. In the mean time you may spend unecessary time and $$ and your tires will wear flat spots.

I recently went through hell with Goodyear and 4 new Silent Amor Wranglers...I went to 3 Goodyear service centers for tire balance 7 times and finally I ended up paying an extra $140 to have an independent tire dealer balance my tires properly. It took 4 tire exchanges(a total of 8 tires) to find 4 that didn't road force test aat 20 lbs. or more and that didn't vibrate excessively.

Have your tires road force balanced on a newer Hunter machine with 1,400 llbs. force pressure and have them give you a computer print out of the results.

My 98 4runner still shows some sutle vibration from one of the tires that measures at 13 lbs. force variance.
Anything around 20 lbs. or more variance is likely to show up as vibration on the 4runner.

 

[unlimited96]

sounds like a balance issue, took me several times to to get the shake out of my cooper stt's, although last year my ball joints were sloppy which felt like a wheel out of balance. you fill it more with offroad tires or a/m wheels.

 

[mx52nr]

Thanks for all the responses guys, I've been out of town and haven't been able to check the site as usual. I'm planning on taking it back to Discount tire where I got the balance/rotation done a few weeks before the shaking started, and have them double check their work. But the whole vibration thing started before I had them balance and rotate the tires....

When I checked out the exhaust system, the catalyic converter was pretty beat so I went ahead and replaced that, and I noticed a small crack in my exhaust manifold - that is getting replaced this week... Replacing the cat did help out with some of the sluggishness I felt around town, and I'm really hoping that after I install the new manifold the whole shake issue will magically resolve itself.... I'll keep yall posted...

On another note, I'm putting the truck up for sale... I'm having monetary issues and can't afford 2 vehicles, school, and a mortgage payment... Anyways you can check it out in the classified section...

 

[mx52nr]

sorry to revive an old thread, but I wanted to let you all know what was happening to my truck in case you were following it... I had the vibration checked out at a dealership, and it was determined that the vibration was caused by a worn u-joint. I ended up selling the truck before i could get it fixed, but informed the buyer of it, he had his mechanic look at it and fix it, and from what i understand it's back to driving like perfect...

i didn't know this but older 4 Runner's are quite desireable in South/Central America. Almost everyone that came to check mine out were intending to transport it out there, including the person that eventually purchased mine...

 

[drmorbius]

Btw warped rotors would only show up when braking, not under hard acceleration.