COZ

Newbie here...

I've been through the many vibration threads and have a twist on what's already been posted.

My problem is a very intermittent but violent front-end shake. 90% of the time my 4runner drives great but all of a sudden I start getting a vibration in the front-end and steering wheel that keeps gaining until I'm about off the road.

Mostly happens at 40+. Recently I've replaced the tires with LTX M/S (265/70/16) and had my rotors replaced, front / back pads replaced and back drums ground. I have 92K on the truck.

No pulling or vibration otherwise. Truck stops straight and in good time - no pulling or fade.

Once the vibration starts it will continue until I stop. While stopping I get a strong vibration and pulsing from the brake pedal. Once I've stopped the problem goes away. Sometimes just for a couple of minutes and sometimes for the balance of my drive.

Is it ok to rule out tire balance since it drives fine a vast majority of time?

My mechanic has looked over the front end - no problems found.

The real kicker here is the long period of time (days, weeks) between problems and that I can't duplicate at will.

Ruled out;
- Snow/mud in rims
- dry .v. wet conditions
- tire pressure / balancing (i believe)

Any ideas - really getting to be a pain and I'm afraid there is an underlying problem or I may be causing one.


Thanks,
- COZ

Nobody

I was starting to get a slight 'bounce' from my front suspesion before I repalced the shocks..maybe one of your Bil's is bad?

COZ

Ok - I have 60k on the shocks but they seem to be fine. Plus wouldn't a shock problem occur all the time or at least all the time within a speed range?

This problem comes up quick w/o warning and on good road conditions. No slight vibration or bounce here either - it feels like my front end is coming apart or a tire is coming off.

Unhappy99

Have your suspension dude take a look at TSB PG027-02, upper ball joints.

Something is definitely loose up there, recheck tie rod ends, steering free play, ball joints, wheel bearings, alignment eccentrics, shocks and their mounts (particularly the lower), and spring seats.

I'd put a torque wrench on all of it. There is a recall for your rear springs, but this doesn't sound like this problem.

p.s. Do you mistreat it? I once had a jeep I treated quite poorly for a long time, to the point where there was so much frame fatigue it shook violently.

MTL_4runner

Does it feel like just the steering wheel is shaking or is it the entire body of the truck?
Front suspension parts you should feel it in the steering wheel.
If the body of the truck is the offender, you need to look at other parts of the system.

COZ

Unhappy99 - will look into the TSB and I agree that something is "loose". Specially since there was a brake job and new tires in the mix over the past month or so. Also - no abuse whatsoever....
I baby the truck. I'll get some pictures into my profile. Hastings oil filters, mobil 1 every 5k, etc... No off-roading with this one. My 92 had all four wheels off the ground before I had 25 miles on the truck. My '98 is babied.....

Anyone know where to go to read up on TSB's?

MTL_4runner - I feel it in the front end and steering wheel mostly. The whole truck gets to vibrating but definitely starts in the front-end. The best way to describe it is 5 lug nuts fall off and the 6th one is loose.

Thanks
- COZ

Unhappy99

The stealership must allow you to look at the book of TSBs anytime you want at no cost. You might even get them to print it out for free, too.

Was it shaking before the new tires and brake job? I know (you believed) tire pressures are ok, who checked them?
Very low pressure can cause shaking.

COZ

Air pressure is at 30 pounds all the way around so looking good there. The "I believe" comment I made was directed towards the balancing since I had the local Merchants Tire replace the tires. I assumed they did the balance right. Remember my problem is widely intermittent - I would assume a balance issue would flare up often and be consistant.

I did have a slight shaking problem prior to replacing the tires. I had 275/16/70 BFG AT/TA tires with 43k and they were beginning to talk and shake. However, that shake went away with the new tires.

60k on Bilsteins that have not seen heavy loads and too aggressive driving should still have plenty of life right? I have very little roll and they feel fine. I thought I saw somewhere that Bilsteins had a million mile / lifetime warranty.

My kicker is the infrequency of the problem. I can go days to weeks w/o a problem and then out of the blue - bam. Different roads, speeds, weather - nothing seems to be a pattern.

Unhappy99

Not to say they can't go bad, but Bilstein has a very low failure rate. And yes, with only 60K on them, they should have plenty of life left. The rest of the 4Runner will die before the Bilsteins.

And yes again, a tire balance or rotor warp issue should be more consistent. I think you've got a few nuts and bolts loose.

goldtaco9

I had this exact problem with my old Syncro. It was a balljoint but it was very hard to diagnose. It would go for long periods of time with no problems and then develop that scary as heck shake. I thought it was a front CV but it was a balljoint.
Good luck,
Mike

MTL_4runner

Given what you answered to my questions and the randomness of the vibration, I agree that it must be a balljoint that is causing all your problems. Check both the upper and lowers just to be sure. Could also be tie rods so check those too while you are under there.

Mikey

Check the rack. See if there is any slop, expecially on the drivers side. Shake the wheel side to side and see if it moves. Tacomas seem to have a problem with these. Is there any weird tire wear?

COZ

Here's a followup - I noticed a foul smell after a recent drive where the vibration started after several miles of driving.

Checking my brakes I noticed the left rear (drum) was glowing red. Seems I have been dragging a brake around just enough to cause problems but not enough to notice under power.

Think this could be my intermittent vibration source?

My mechanic will be looking at it again. 1st time we thought it to be the parking brake and made an adjustment. However, I'm still dragging that wheel.

Anyone, had a problem with a locking drum brake before?

calgarysteve

Seems a lot of these threads go dead once the person actually fixes the problem but then doesn't post the information. I too have fixed and replaced everything on my 1990 4runner and cannot figure out why I am getting a sudden and intermittent vibration from the front passenger wheel. Anyone who has had this problem and has fixed it themselves please please please let us know of your experience.

calgarysteve

Fixed my problem with changing the lower ball joints on both sides. I still have a rattling that has been present but getting worse over the years. sounds like the break pad shield rattling. Turns out its a brass bushing in the steering spindle that wears out. The fix is a bearing that Toyota sells instead of the bushing.