aowRS

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 'shudder'. 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 '99 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 - 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 Wheeler's. 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 (Goss's 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 'clunking' 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 'shuddering' 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 'shudders' 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. It's 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 don't 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 275/70/16 REVOs weighed 43 lbs each. My original 265/70/16 Dunlops weighed 36 lbs each. That's 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

mpavolka

Has your car been in for new ball joints? I know a lot of the 00-02 4Runners had a recall on the ball joints. If you have replaced the steering rack and there has been little abuse the bushings on your control arms should not be in bad shape. Maybe check your tie rods as well, but they were probably replaced with the rack.

aowRS

Thanks for the reply. I've owned the truck since new and have never received anything the mail regarding a recall. Is there a way to find out if my VIN was included?

I replaced the entire rack, including the outer tie rods. The issue is definately not steering gear related.

Andreas

PoleVaulter95

well i have that same shudder in mine but mine is a 2nd generation (we might have dif set ups). anyways, from what i have gathered it is spindle bushings (where the cv comes into the knuckle) they get worn and the cv shaft bounces inside it. try crawling under your 4runner and grab that cv and give it a good up and down shake. i can feel the slop/ hear the metal on metal contact where it comes into the knuckle. hope this might point you in the right direction

aowRS

Hmm. I think the shuddering I have is one or more of the following: control arm bushings, shock eye bushings, upper ball joints, or lower ball joints.

I'm not sure how the problem could be axle-related as the truck is glass smooth until I hit a rough spot in the pavement.

Andreas

mpavolka

Have a dealer run your vin number and see where you stand on that. As for loose CV axles that was a problem with my 1990 4Runner but have not heard of it in the 3rd gens.

surf4runner

i found it https://www.yotatech.com/forums/show...l+joint+recall
not a lot of detail, but has the info you want

SOAZtim

I have an 01 with the exact same shudder. It feels like there is play in the steering wheel. Weird, my tacoma never had it. I have yet to figure it out, but its been there for the last 15k miles and I've not had a problem, but I want to get it fixed.
I was thinking balljoints or higher up in the steering system, above the rack...?

Has anyone who has this gone to aftermarket upper a-arms. Did it go away???

aowRS

Tim,
We have the same tires. Did the symptoms start after installing the 265/75 REVOS, or were they present before?

If the upper ball joints are easily replaced, I may go that route and slowly work my way through the rest of the front suspension. After paying for two alignments in the last 4 months, I'm not keen on dropping the lower control arms to inspect the bushings.

Andreas

SOAZtim

no, it was there when i bought it and it had the stock tires.
If thats the problem I'll be replacing the ball joints too.

aowRS

Bump.

Andreas

Baloo

This might help on the recall info.

Keep us posted. I am trying to diagnose a similar problem on my 01 taco. I am going to start by gettting the Energy Suspension kit that basically replaces all the rubber bushing with polyurethane then work my way from there.

Several times in the shop and always told "everything looks fine" and that I can expect some problems on a vehicle with 117K on it. I thought I hadn't even completed the break-in period yet.

aowRS

Baloo,
Thank you. Please report back about the polyurethane components, and any difficulties encountered replacing the control arm pieces.

Andreas

Gerdo

What psi are you running in your tires? I have load range D (65psi max) and I run 32psi (LT265/70R16). I can go slow on wash board roads or I can blast down them in total control. What shocks do you have? I know that you 55k miles on them but they may be shot or just too stiff. I love my Bilsteins.

aowRS

Gerdo,
I currently have the tires at 35 psi. Dueler A/T REVO, 265/75, standard load (SL). The shocks are Bilstein.

I shudder (pun intended) to think of taking the truck down a washboard road right now. In fact, I think I would refuse

Andreas

mtnwheeling

I have the same issue on my 00 Tacoma. I have TC upper arms with new bushings, new lower ball joints, new tie rod ends and poly rack bushings......so the only thing left for me to replace is the lower arm bushings. I also have play in my steering column shaft...which Toyota says is "very rare", but it makes a lot of noise.

Extra info: 33x10.50 bfgs @32 psi on 15x7" rims and recently aligned.

SOAZtim

I dont know what kind of shudder your getting, but mine is defianately not form tires. If feels like only one side of my steering is a little loose. The shake seems to come from the front left tire area. No the tire or wheel itself, but the steering components. I you take your hand off of the wheel when you hit a good bump you can see it jerk ever so slightly. Smooth bumps even if I bottom out are fine. Its when you hit a rock or something abrubt....