BOSTON4RUNNER

I have a 1997 3.4 Liter 5 speed 4WD 4 Runner

I recently balanced the wheels in order to smooth out a vibration that I get at about 60-65 mph, at 70 it smoothes out completely, my tire balancing did not make a difference, there is no shake in the steering wheel or shifter. Although I can say that some other minor vibrations that were in the shifter and steering wheel did disappear with the balancing, however this other vibration which I was hunting for, which seems to be in the rear, is still around.

If letting off the gas and letting it slow down from 70 to 60 mph you can also feel it, I also feel it with the clutch in, case that should be an issue.

I visually inspected the undercarraige, all seems good, driveshaft is tight, as is the rear bumper etc.

The truck is not lifted, the tires balanced perfectly, but I did move two of the fronts to the rear recently, as they had some rounding on the inside.

I wonder if this is where the problem may be coming from? I also do need to do steering rack bushings, as I can physically move the rack in and out of the bushings when the front end is raised, it is not like a hot dog down a hallway but there is definite play.

I also need to shocks, struts and have a ton of stuff on the way, diff drop etc to lift the truck, so I am thinking tonight I will move the rear tires back to the front and vice versa, see if the slightly rounded out tires in the front remove the vibration, maybe the front is better compensating for this for some reason.

any thoughts? I have read other threads that seem to point to tires, balancing, rack bushings.

thanks, tim

02SE

Has the driveshaft been lubed regularly over the years?.

There are 3 Zerk fittings in the double-cardon joint, 1 Zerk fitting for the slipjoint, and 1 Zerk fitting in the rear U-joint.

It's possible you have some wear on those joints, even if they have been regularly lubed, depending on mileage.

My .02

BOSTON4RUNNER

i will have to check those out,,,,thanks!

supahonkey

The u-joint is probably going bad... it probably has a crack in it. Depending on the severity of the crack, it could cause an extremely slight vibration, or a nasty one if it gets worse. I've seen cracked u-joints last a while (6+ months) before they finally stop working.

If no one greased the driveshaft then it could be the cause of your vibrations. If the driveshaft isn't greased then the splines on the stub and the yoke will eventually wear, causing some slop in the driveshaft. I know that you mentioned that the driveshaft seems tight, but so did mine, and it was the source of some nasty deacceleration issues.

Lastly, a piece of dirt on the inner face of the wheel could cause vibration. Anytime I go offroading, the ride home is always full of vibrations because of mud. Sometimes the culprit is a little bit of mud, sometime's it's a lot.

PeteV

http://www.gadgetonline.com/vibration.htm

There is a ton of great info. here. Cured my problems.

BOSTON4RUNNER

MAN O MAN

THANKS

my dad is in the automotive field himself, he is going to find one of his accounts that have a hawkeye balance set up

it does it only 62mph to 72mph then is totally smooth

sure feels like tires, mis balance, as I had this happen in other cars before

thanks alot, and great site! here is my site case you want to check it out www.sfaboston.com

tim

Nic

If you have bad tires, no amount of balancing is going to help. The Dunlops I had on my truck gave me fits trying to figure out what was causing my vibration-at about 65mph, just like yours. Out of frustration, I bought some Michelins and haven't had a problem since.

If you can have someone in another vehicle follow you at a relatively close distance at your problem speeds, they should be able to see the bad tires shaking-if that is what it is.

BOSTON4RUNNER

this weekend,,,,steering rack bushings and suspension,,then will replace my one kinda bad, rounded out tire, have it aligned, then have the wheels blanced with that haweka balancer

i am betting that is part of the problem, sure feels like tires

MTL_4runner

If you have a fullsize spare you can also rotate that around to see if you can track down the offending tire(s).
Lug-centric balancing should cure it if it is a tire balance problem (won't fix tire defect issue)

BOSTON4RUNNER

going to have the tires Road Force balanced tomorrow, with the Haweka adapter

I have two new front tires

...the vibration is present from 62-70mph or so then almost completely, well would say completely smooths out

I do not think it is a u joint, or driveshaft, as I am assuming it would be more consistent...I am hoping a good balance takes care of it

I will also again check out the shaft and u joints tonight

any other thoughts? tim

BOSTON4RUNNER

...quick update

I am leaving for the Outer Banks tomorrow night, but there is a little swell here, so after work went to catch some waves

I made arrangements for the morning to have my wheels balanced,,,but then when driving home from the beach the vibration seemed to be creeping in at different speeds..

so I got home, went underneath...and even though I checked it pretty good a few weeks back when the vibration was slight,,,and it looked ok,,,,the rear u joint at the axle flange was completely destroyed, lucky it did not let go

I have the new u joint, and luckily my dad will run it over to the machine shop tomorrow, the old clips are out but our vice is broken and we dont have anything to press them out

so hopefully, I will throw the shaft in tomorrow after work and then hit the road to NC

in the last week, I did a steering rack, steering rack bushings, 3 inch lift, diff drop, new tires etc etc

I hope this is the last of things for now...and hope it goes well

I do find it odd that the u joint mimicked symptoms of tire balance issues, also that there were no heavy vibrations up through the shifter, I guess most was given to the rear axle, rear suspension then resonated through the truck