My 4Runner has developed a very annoying symptom in the front end. When going over minor pavement irregularities or ripples, the front end will exhibit a significant æshudderÆ. Normal dips in the road will have no effect. It is actually alarming enough that I am taking the time to post this, rather than laying on my back under the truck theorizing on what may be amiss. I welcome any and all thoughts, and will attempt to explain the current state of the truck.

I purchased the truck new in 2001 and now have 125,XXX miles on it, mostly highway.

At around 70,000 miles (three years ago), I replaced the stock suspension with a set of Bilstein HD shocks and factory new Æ99 4WD/auto/V6 coils. Shortly thereafter, I ditched the stock 265/70/16 Dunlop TG35 Grandtrek tires and installed a set of 275/70/16 Bridgestone Dueler A/T REVOs (standard load). This combination gave me a great ride, whether on the highway or during mild off-road usage. With fairly religious 5,000 mile rotations, I was able to get close to 50,000 miles on the REVOS û I loved the way the truck rode and how it looked with a slightly fatter tire. Tire wear was even for about 40,000 miles before the tires started getting loud. Before replacing the tires, I noticed quite a bit of lateral play in the steering rack, so I replaced the rack bushings with polyurethane pieces from WheelerÆs. I also replaced the completely-degraded sway bar bushings with polyurethane pieces at that time.

At 120,000 miles (January 2007), I replaced the worn tires with a set of 265/75/16 REVOs (standard load). I think this is where the symptoms became noticeable. At the time, the shop (GossÆs Garage) noticed that I had significant play in the steering rack, which would make an alignment difficult. Since I was there and witnessed the play, I decided to personally replace the rack with a factory new piece. Prior to this, I had noticed more and more play in the front end, as well as a distinct æclunkingÆ when going over uneven surfaces. I replaced the entire rack (plus tie rods) a few weeks ago (with a bad back) and then had the truck properly aligned (the front left camber bolt refused to budge, so the shop resorted to a torch and brute force to remove it. The threads were gone and I bit the bullet for a new bolt set from Toyota.) The next day I took it on a 1,000 trip. It was very smooth, but the æshudderingÆ issue reared its head constantly.

So here I am. The truck drives very smoothly on the highway, but as soon as I drive over a fairly-small pavement irregularity or rough patch, the entire front end simply æshuddersÆ very noticeably. When this happens, I can see the hood shake, can feel the 'shudder' through the steering wheel, and can see the dashboad shake. ItÆs only for a second or two, but is so distinct that I am determined to find the cause. I know these are trucks, but I have enjoyed nearly 6 years of reliable, and smooth driving. The condition is annoying enough that I donÆt even want to take the truck beyond normal around-town driving, and cringe when I see a rough patch in the road.

Here are some thoughts that have crossed my mind. Bear in mind that the truck is otherwise stock and has been overly maintained by myself. Even at 125,XXX miles, the truck looks new from 10 feet:

- Upper or lower control arm bushings. Has anyone experienced failures of these? Are they replaceable?
- Lower shock mount rubber bushings. I presume these are cast into the eye and are not replaceable?
- Worn front shocks. These are roughly three years old and have around 55,000 highway miles on them. Absolutely no off-road abuse.
- Excessive tire weight. The 265/75/16 REVOs weigh 45 lbs each. My former 275/70 REVOs weighed 43 lbs each. My original 265/70/16 Dunlops weighed 36 lbs each. ThatÆs a nine-pound difference between the stock tires and what I have now, but only a two-pound difference between the REVOs.
- Failed lower control arm bushing. Excessive heat from the torch may have roasted the rubber bushing.

Please let me know your thoughts. I appreciate any and all responses, but am really looking for some real-world possibilities/solutions. Thanks in advance!

Andreas

You might need to to take your VIN to the dealer for a lookup

Ball Joint Recall

I'd get that bushing looked at too.

I would put the front end up on jack stands and just pull on everything to see what you can get to rattle or see where there's any play in anything.

Jeff,
I aim to do this tomorrow.

Out of sheer curiousity, how difficult is it to replace the upper and lower ball joints?

Andreas

There's a couple of links sticky'd over in the Taco section for your application; give it a read-thru. I think the shock/coil assembly might need to be taken out of the way; just did my front shocks a couple months ago. A 14mm gearwrench is handy in that area.

It's a tad different than my older Toys; R&R of BJ's on them isn't too bad.

I've never messed with replacing the lowers. I've replaced the entire upper control arm with Camburg uni-ball arms so it would droop more during flex. It was a little frustrating but do-able for most people.

I have a 98 4runner sr5 with 90k on it. All stock with new tires until I started experiencing the very same shudders over small bumps. Especially when going over them at low speeds. I replaced the steering rack thinking that might have been it. Then I replaced the lower left control arm(seems to be the side of shuddering). Am thinking of putting Bilsteins on because I am at the end of my rope. Please let me know if anything you find works. I feels like its unsafe as well.

My 1990 4wd 4-Runner does the exact same thing. I haven't been able to figure it out either. I haven't had a whole lot of time to get under there to try to figure it out though. If you come to any conclusions, please let us know!

Did this come with bushings already installed? Were the bushings available separately as well? Cost?

Andreas

I just did a bunch of PM to the 4Runner so I spent some time underneath and noticed that most of the bushings throughout the front end looked pretty shot... anti-sway bar and steering rack included.

I've noticed a sloppy feel developing in the front end and suspect it's the bushings. Anyone have a source for a replacement bushing kit?

BTW, my OME springs (installed about a year ago) have really "softened" up... they feel great and the shocks definitely feel in control over most road conditions, but the short, choppy stuff is really starting to rattle my cage. <img src="/forums/images/graemlins/scared.gif" alt="" />

~Dave
111,000 miles and counting