Chasing a front end vibration

Ive tried everything. Ever since coming back from a wheeling trip last November I've been chasing a front end vibe and only finding the symptoms but not the cause.

Especially at Highway speed, the steering wheel wobbles about 1/2-1" left to right and the truck shakes like a tire out of balance.

FWIW, I run +5 Caster on SPC upper control arms, and my cams cranked to the max.

I've replaced the LCAs because I thought the lower bjs were bad and my balljoint press wasn't seating well enough to press them out. So on went some used 4runner lcas.

Next I noticed play in the driver's side outer tie rod, so I replaced it with new OEM.

Next I noticed play in the driver's Wheel bearing. So it got a brand new wheel bearing from the guy who presses them up here on TW.

Next up my passenger balljoint (SPC) had a ton of vertical play when I pulled the passenger tire to check it's bearing. So new SPC joints on both sides, as the driver side ended up with some play too.

I can't seem to pinpoint the cause.

I can only think it's maybe:
-An inner tie rod
-The passenger wheel bearing is starting to go, but not enough that I can tug on the tire and feel it.
-Somehow all my wheels are bent (I've tried swapping them with the spare and even gotten a five tire rotation)
-The rack and pinion is going out
-The coilovers are under sprung or dying. (Bilstein 6112s, 650lb coils, around 50k miles. I'm heavy. Full plate bumper, full plate skids, and extremely heavy sliders, 1/4" wall.)

If you all have anything to chime in, let me know.
I still have another outer tierod to try on the other side and another wheel bearing to try.

 

Steering sector shaft is a known replacement item on those.

 

Check your steering rack mounting bolts/bushings and make sure they aren’t roached.

How much lift? What size and kind of tires? Had them rebalanced (or road force balanced) lately? Alignment?

Might also have so much caster that it worked the rack & pinion too hard and it’s dying a progressive death.

Could be UCA bushings. SPC arms aren’t my favorite for their history of failures, happy I got rid of mine.

Just more ideas. Good luck.

 

Could be all the tires need rebalancing.
4-wheel alignment, maybe crabbing a bit.
Any fluid leakage from the struts?
Check the strut mounts for cracked sheet metal.
Also the core supports and around the battery.

 

Ive had them rebalanced a few times now, but 295/70R17 Falken M/Ts, but the vibes started with my dry rotted 255/80R17 Falken wildpeak AT3Ws that I thought were the culprits as they were cupped.

Lift is like somewhere in the real of 3-4". 6112s are on 2nd from top preload setting.

Alignment after replacing the LCAs and cams.

 

^^^^

 

Ive had them rebalanced a few times, on the old set at least 3 times since it began, and this set twice.

 

Any way to test this before dumping over $200?

 

Can't do a 4 wheel alignment on a solid rear axle lol

+1 for checking the mounts as bushings etc as you suggested

Yes. Put a new one in and if the vibes are gone, problem solved!

Oh you said before $200.... Well .... Uh.....

Run really fast from the parts store once you have it

 

i had the intermediate shaft fail on my grey tacoma it didnt cause vibes it made it hard af to steer. after it was replaced it was easy to steer the truck again.

 

when we were talking last night it sounded similar to when my lca bushings completely failed on my grey truck. the only thing his isnt doing that mine did was move. from stopping to starting my lowers would shift since the bushings were bad...

i still wonder if you have bad bushings somewhere on the front end. not all of them but maybe a few of them to cause the issue.

 

Not looking to add to my rap sheet.

Anyways, after yall saw the video of the steering shake, which I may have overexaggerated a little, it's more like 1/8 inch, but it can get worse than that, or be almost gone randomly.
Also noticed that around 25 mph I hear a growling seeming to come from the right. Hoping it's not a diff, and just the other wheel bearing starting to fail. I have the other new bearing to swap into that side, guess I could replace the tie rod end while I'm there since I also have a new one for that side too.

Other thoughts that came to mind. Pretty sure the CVs I got were 3rd gen part numbers, and both were the same number. I really don't remember. Wondering if they are slightly longer maybe or one side is a different length?

 

I'm thinking maybe it could be the bushings on the front diff. Could be shot and allowing the whole front end to vibrate?

Also there has been a very very slow seep on the rack and pinion, as the boots have looked damp for years. Power steering level has never dropped significantly, and I haven't had to add any fluid. I'll give it a check though.

Another though could be that the power steering pump is on a slow death, and the road feedback has gotten too much for it to hold at bay. but it doesn't whine or anything even moving full lock to lock.

 

Damn, I should've bought new coil overs a few years ago when they were half the price they are now....

My train of thought is that the tires are cupping, I added more weight to the truck before embarking on these used coil overs on a trip from KC to Windrock Tennesee and then wheeled for 3 days and drove back. Then I daily'd it for a few months before taking it out one more time. Then I increased the preload a bunch, 2nd from top slot on the 6112s, 650lb coils to try to regain the inch I lost from the sliders. I was cupping prior on my old tires as well. Tired shocks + cupping = tires keep going out of balance, exacerbating the amount of bounce, and the cycle repeats. Every time I balance the wheels, it feels a bit better for a few days. So the bouncing over time just wears out everything and leads me around by the nose chasing the worn out parts.

Any flaws in this theory?

 

i mean it could be? ya never know until you look into it.

maybe it leaked at one point in time but then it stopped?

possible? anytime ive had one die it was always screaming for death so i havent had one slowly die lol but anything can happen ya know.

 

Can’t say anything about flaws in the theory. But what I can say is the reason I dumped the SPC UCAs is because they were cupping my tires due to trash ball joint and bushing design. Even though you’ve replaced joints they still could be trash. My problems were fixed switching to JDFab UCAs and rotating my cupped tires to the rear to let the road flatten them back out for a couple thousand miles. No more cupping, no more play up front. I’m going to go on a limb and guess you haven’t switched due to all that caster you are running with. Might be time for a plan B on those.

 

Should be the same for both sides

All power steering leaks. If its not lowering the level in the resi, I wouldn't worry about the leak itself.

I just pulled used pro coilovers off my daily and put my old sport shocks back in. Way better. Tired shocks suck

 

You need to pop off the brake calipers and look for seized or seizing pistons.... I always had trouble after wheeling....water and mud get all in there and then you can really get vibrations when one of the pistons doesnt retract how it should...usually the lower ones as they hold the most crud.

Last time I went out I think it must have seized up during the actual wheeling, as the ride home sucked....vibrations...did actually feel a drag on the truck on that one.....once I got into it, was apparent one of the pistons didnt want to press in very well at all.

 

I've kinda suspected maybe it was brake related, but it was low on my list of culprits. I'll have to dig into that this weekend.

 

Took it to a shop for a diagnosis and he's pretty sure it's bushings, either control arms or steering rack, or both. He said it could be a combination of a lot of little things having play adding up to the vibrations. I ordered poly control arm and steering rack bushings from Energy Suspension, and will get to it hopefully this weekend while it's a little cooler.