taco_ted

First of all, this is my first post but I have been reading this forum for quite some time.
Now onto my predicament:
I have a 98 Taco, and after a state inspection (which we all know can be more harmful than helpful) my truck has developed this front end shake at all speeds. At lower speeds it isn't as pronounced, and it isn't always horrible at higher speeds. It just seems that sometimes it will settle into this oscillation that just hammers the front end and you have to speed up or slow down to get the vibration lessened.

I had the wheels rebalanced, and that didn't change anything. I then rotated the wheels front to back (it needed it anyways) and the problem is unchanged. Brakes seem linear and smooth, and steering and handling is identical to before. There is no vibration through the transmission or transfer case shifters. The vibration occurs in both 2WD and 4WD modes The only thing that has changed is the vibration through the steering wheel and dashboard. My suspension setup is Bilstein 5100's on stock springs up front, although the shocks are less than a year old. Tires are also less than a year old, BFG A/T KO's. The tires have a more pronounced rumble and the shake is in sync with the "wah wah wah" rumbling sound the tires make. However, I would think after balancing and rotating the issue would at least diminish or change in some way.

I have searched up and down, but it seems like everyone has a different case. I want to avoid replacing parts arbitrarily if there is any helpful advice you guys can offer. Is it a defective strut? Or a steering linkage? I am pretty sure the inspection guys have to take the wheels off to inspect brakes, so is there a part their lift contacts that they destroyed due to carelessness?

sebastianholmes

does the front drive shaft on the newer trucks turn all the time? that could be it

taco_ted

I would assume not, since the hubs are automatically locking. If it was always turning, then my speed would be limited to the quoted 55mph limit for use in 4HI setting. Right?

sebastianholmes

yea i guess thats true. what was involved in this "state inspection"? did they mess with amything? was it right after the inspection that it started? do you think they caused it?

taco_ted

I don't know 100% what is involved in the VA state inspection, but I know they have to take the wheels off because they inspect the brakes. It started doing this after the inspection so I have to guess they did something. I don't know how they lift a car to remove the wheels, but I would assume the load of the truck weight is applied to the frame so the suspension can hang free.

taco_ted

So, I went and made a thorough observation of my truck, and found that there was buildup up oil or grease on the skid plate and around the passenger side steering gear dust boot, as well as the passenger lower ball joint. My power steering fluid does not seem low (there is also no whine typically associated with that) as it is over halfway up the COLD marker on the dipstick.
Based on the photos I took, does it appear that the lower ball joints need replacing? Could this be the cause of my problem? Is this a safety issue (i.e., catastrophic failure) or am I safe to drive it until I can get it fixed?
Also to note, the passenger dust boot has a cut in the top of it, because as soon as I rotated it, fluid started leaking out. I assume this boot is supposed to contain fluid within it, however. Opinions?

BlackFive

Perhaps hub-centric wheels were not torqued while wheels off ground.
http://www.toyota-4runner.org/perfor...must-read.html

taco_ted

Hmm. It is true that the wheels hadn't been removed since I had the lift done and tires installed last spring, however, in the past I had removed and torqued wheels myself with the wheels on the ground and never had this problem. Plus I wouldn't imagine after having them pulled off a couple times and rotated that my problem would remain unchanged.

BajaRunner

Jack up the front tires, grab each one at 12 o'clock and 6 o'clock, and push/pull the wheel. Does it move? If there is some movement then either your lower or upper ball joint needs to be replaced.

Now grab the wheel at 9 and 3 o'clock and shake. Does it move? If so then your tie rods are starting to go or your steering rack (OR BUSHINGS) need to be replaced.

Obviously there is some gray area here. I've been able to shake my wheel slightly in either direction and its been fine. If there is a considerable amount of movement then I'd look into it further.

The most common occurrence with these trucks is the rubber steering rack bushings will start to go. If you have your truck on the ground, have someone jump in while you are underneath looking at the rack. Have hte person go back and forth with the steering wheel, and see if the rack moves around. There should be a little/tiny bit of movement, but if its moving considerably that could be your problem. You can buy aftermarket polyurethane bushings from Wheelsrs offroad for like $20 or something.

taco_ted

@Baja: Thanks so much for the suggestions! I checked it and there is no up/down play but I can shake forward/back (9 and 3'oclock) maybe a centimeter or so in either directions. Having someone turn the wheel, I noticed that the steering rack does move, and the bushings look pretty old. I will replace the bushings and tie rods and post back with results.

taco_ted

Also, if there is fluid in the bellows, does that indicate a need for a replacement steering rack? I originally thought there should be oil in there, but after further investigation have learned this is not so. The inner tie rods shouldn't hold back steering fluid, right?

jrm

Does that mean that you had the tires balanced at the same time or just before the state inspection?

I have a feeling that it wasnt the state inspection that created the vibration it was the hub centric wheel-tire balance. And if you went back to the same place and had them re-balanced using the hub-centric method then the vibration remained.

If have the same aluminum wheels that came on the 96-02 4runner they require a lug centric balance otherwise you can re-balance um till your blue in the face and theyll still be out of balance.

http://www.4runners.org/writeups/haweka/index.html

scuba

That is all.

blake.nemitz

ya catastrophic failure!! my friend drives an 02 4runner, i know but same front end underneath, and her lower ball joint let go on the highway, good thing she wasnt killed, thay are know to be weak if there is play REPLACE IT

taco_ted

Actually, I had the balance after. Here is the timeline of events:

1. Someone runs into my front bumper while parked and out of town. Cosmetic damage, drove 300 miles home without a problem.
2. Realized I needed an inspection, took to my local shop for inspection.
3. Failed inspection due to leaking axle seals and gear oil in rear brakes. Replaced seals and rear brakes. (funny how I never noticed a performance degradation from this. Guess rear drums are pretty worthless)
4. Returned to same shop, passed inspection.
5. Took to a different shop to have brakes bled (couldn't get it to work myself for some reason), they only used a drive-on lift.
6. Noticed vibration on the highway.
7. Had wheels balanced at the local Merchant's Tire store.
8. Vibration persists.
9. Rotated tires, vibration persists.

I am going to replace the entire rack assembly, bushings, and tie-rods this weekend and will report back. The ball joint doesn't have any play (play is only front/back, not up/down), so I am ruling that out for now.

From what I have seen, it seems that the bolts that hold the ball joint in place are where the failures occur most often. Out of curiosity, has anyone simply replaced the bolts as a preventative measure? If the attachment point is the critical element, it seems wasteful to replace anything but the fasteners. I am not personally worried, I would imagine the guys who did my lift last year (and a mounting, balancing, and alignment) would have alerted me to anything fishy, and as stated before I didn't exhibit any of the typical ball joint wear syndromes.

scuba

The ball joint and tire rod pictures you posted don't look bad.

If I were you, I would replace the inner tie rods and the rack bushings before going and replacing the whole rack.

taco_ted

That's pleasantly reassuring.

I was planning on doing that, but after finding a considerable amount of oil in the bellows, I concluded the inner seals must be bad. Since I am doing little more work (just spending more money, of course) to replace the whole rack I figure it will take care of every possible point of failure.

I will definitely take some pics and post back on the results after I perform the installation this weekend. Fingers crossed!

Kiroshu

I noticed the truck in your avatar? Is that the truck? That bull bar on the front..... is it loose? And if so it will cause vibrations.

Have you tried lowering tire pressure in the front wheels to see if the vibration went away a little?

taco_ted

Negative, it doesn't seem like the lights beam pattern bounces enough when it starts oscillating to be sourced from the bar. Good thing to check though!

I haven't tried that, but I will if the new steering rack doesn't fix the issue. Another great suggestion! I think I will put together a troubleshooting guide for this issue because it appears all over this and other forums but never in one place. Having test procedures and solutions to try based upon difficulty and cost is probably handy for more than just our trucks.

taco_ted

Here is my report, post-installation.
First of all, here is what I replaced:
-Outer tie rods (Beck/Arnley from Rock Auto)
-Power Steering Rack (refurb from Discount Steering)
-Steering Rack Bushings (Polyurethane kit from Energy Suspension)

After installing this, I found that road vibrations are transmitted much more through the steering wheel. At first, I thought my front end problem was continuing, but I think the tires are just an aggressive enough tread pattern to create a vibration or oscillation at certain speeds and road textures. The dashboard and front end doesn't seem to be vibrating when I feel the shake (which is much more subdued and does not feel unsafe) through the wheel, so I think it is just a result of the increased steering feedback. It is clear that the poly bushing are quite firm and really make a difference in how well the truck handles.

I am going to write up a troubleshooting guide for vibrations because it seems like the hardest part about solving an issue like this is knowing what tests to perform and interpreting the results of those tests.