mountaingoat

Howdy folks,

I'm trying to help my neighbor figure out what's gong on with his truck. It's a 2002-ish Tacoma, 4WD V6 extended cab.

At interstate speeds (75 around here) with a load in the bed (a dirt bike or two) it has a terrifying wobble whenever you hit a bump. Feels like it's got a big trailer with an unbalanced load behind it, the back end just starts wagging all over.

Now, I'd initially thought it just needed shocks - but they were just replaced a week ago, and the wobble is still there. Badly.

I say wobble, because it's a low-frequency affair, not at all like an unbalanced tire. It will ride smooth till a bump in the road (for example, expansion joints on bridges) then it bucks all over hell and back.

I've searched, but haven't found much. Any ideas?

BMcEL

I'd check the wheel bearings and leaf spring bushings first.

4x4climber

Sorry bad info...

scuba

Uh, leafs are springs.
There is no panhard bar on a Tacoma and no rear sway bar either. The truck is leaf sprung.


Please people, if you don't know what the hell you're talking about, please don't make blind guesses.



Op, just cause the shocks are brand new, the valving on them probably isn't meant to handle the load of ~1000 pounds in the bed. You might just need stiffer shocks.
FYI, my Tacoma does the same thing when my bed is full of camping gear and I'm doing 80 down the freeway. Unloaded it's fine.

BMcEL

I thought the LSPV on my 1990 Tacoma was the panhard bar...???



Scuba will you be my friend?

snobdds

Tacoms did not start until 95.5. A 1990 is considerd a regular old pickup or hilux.

This thread is full of bad info.

BMcEL

You missed the JUST KIDDING sign apparently...and in North America they are just 'pickup' or 'truck'.

JLee

X2 he might need different shocks. What shocks are on the truck now?

mountaingoat

Not sure, but given that he had a shop put 'em in I'd guess they're nothing special. Certainly not Bilsteins or the like.

The two bikes together are less than 600#, and I'd really think it would do better than that even with crappy shocks. Maybe they put Corolla shocks up in there...kidding of course.

FWIW - my 90 pickup has hauled more weight at the same speeds with no wobble. I just have basic DeutschTech shocks, nothing really nice, and it seems to handle it just fine.

I do agree that undervalved shocks seem like the most likely culprit.

Had a look at the front end and everything seems kosher. The sway bar is in place and the ends are good. Hell, my sway bar was entirely disconnected for years and it never did anything like this.

JLee

How are the leaf packs? those could be shot along will weak shocks that could cause that wobble

mountaingoat

Even with the bikes in the back, they were still up off the overloads.

JLee

Humm then it sounds like the shocks might be the problem. find out what shock and model numbers they are and i might be able to fine the valving info on them.

michael0584

You say he just replaced the shocks, was it doing the exact same thing with the old shocks? Did the new ones make any difference?

mountaingoat

Yep, it was doing the same with the old ones.

I'll try to get a make and model number off those.

michael0584

If with 2 different sets of shocks it does the same thing, i would suspect something else.

JLee

Humm Maybe the bushings in the shackles

Numark

What basic things have you checked? Have you rotated, balanced or replaced the tires?
With no load would you say it has zero wobble or just not as bad of wobble?

So far I read: You looked at the front end and sway bars. Shocks were replaced.
Anything else?