Unstable Steering Over Bumps

[TheMole]

Been having this issue ever since I bought the car late last year. My steering wheel seems to jerk left/right/wobble when driving over even the smallest of bumps. The bigger the bump, the more it jerks. It drives straight on smooth surfaces. One little dip or road imperfection and the steering is thrown off course. I pretty much have to constantly correct and hold the steering wheel tightly to prevent it from happening. I did notice that it drove pretty nice for a couple of days after I replaced the ball joints and pitman arm, but it came back. Same after I got my alignment. Good for a few days, then back. Also, it seems to be less apparent when I put it in 4wd.

Are my expectations just totally off as the Montero drove like this since it was new? Is this how a truck/suv is supposed to drive? I've recently driven a 98 Accord with similar mileage and it does not have these issues. With 200k miles I don't expect it to drive like a newer car, but am looking to fix this annoyance. Appreciate any input.

Car:
98 Montero full-size w/ 200k miles

Parts replaced:
-Front/Rear Endlinks, 10/2014
-Front/Rear Swaybar Bushings, 10/2014
-Shocks, KYB Monomax, 10/2014
-Idler Arm, Moog, 11/2014
-Pitman Arm, Moog, 7/2015
-Inner Tie Rods, Moog, 6/2015
-Outer Tie Rods, Moog, 6/2015
-Lower Ball Joints, Moog, 7/2015
-Tires, 265/70/15 Cooper Discovere AT/3, 7/2015
-Alignment, 7/2015

Alignment specs


Vid of the unstable steering
https://www.youtube.com/watch?v=ecDMkUNYOsw

 

[SirFrancisDrake]

How do your control arm bushings look? That's about the only thing left to replace up front

 

[KyleT]

Fwiw when I did my alignment to factory spec, mine felt really darty on the road too. I think the toe in spec caused it because I went to zero toe/a smidgen of toe out and it seemed like it felt a lot better.

I too replaced most all the same parts you did.


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[TheMole]

How do your control arm bushings look? That's about the only thing left to replace up front

Most likely they are original and worn, but the last time I was under there they still looked to be intact.

Fwiw when I did my alignment to factory spec, mine felt really darty on the road too. I think the toe in spec caused it because I went to zero toe/a smidgen of toe out and it seemed like it felt a lot better.

I too replaced most all the same parts you did.


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Thanks for the input. The alignment seemed to be in spec so I have yet to take it back. Any idea what your final toe specs were?

 

[jeep-N-montero]

After installing the OME suspension and getting it aligned it rides better than any of our other cars, so you must have an issue somewhere. And we have 33x10.50 km2's that would make any issues even more apparent. Have you checked your tire pressure lately?

 

[TheMole]

After installing the OME suspension and getting it aligned it rides better than any of our other cars, so you must have an issue somewhere. And we have 33x10.50 km2's that would make any issues even more apparent. Have you checked your tire pressure lately?

After I had my tires mounted, I checked the cold pressure and it was 36 psi all around. A couple of weeks ago I lowered the cold psi to f:29 and r:32 for more comfort and closer to factory specs. No difference in the issue.

 

[ahender]

Make sure you check the control arm bushings for play by jacking the truck up and putting a little force under the lower control arm to take the weight off the suspension.

Mine looked fine before I replaced them but the wear was obvious when thoroughly inspected.

 

[plh]

There was a discussion on here within the last year on how the alignment should be set - not just within spec, but actually targeting certain values. None of my trucks feel "darty" on the highway. But then again - they don't drive like an Accord. Both the '92 (115K) and the '93 (185K) have had the same list of suspension parts replaced and also upper control arms. Both of these trucks have also KYB Gas-A-Just shocks. Not as stiff as your Mono-Max.

 

[Blue Baby Sound]

Don't know if this applies, I'm a Jeep guy.
Measure your drag link and track bar to make sure they're parallel

 

[KyleT]

Don't know if this applies, I'm a Jeep guy.
Measure your drag link and track bar to make sure they're parallel

Montero is IFS.


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[Blue Baby Sound]

Thanks

 

[TheMole]

Make sure you check the control arm bushings for play by jacking the truck up and putting a little force under the lower control arm to take the weight off the suspension.

Mine looked fine before I replaced them but the wear was obvious when thoroughly inspected.

I'll take a look when the weather gets cooler around here (100 degrees currently). Seems to be more apparent at city speeds. It's fine and a lot easier to manage at highway speeds. I'm thinking the bushings are more stressed at highway speeds so less movement?

Also, did you replace the whole lca or just the bushings?

There was a discussion on here within the last year on how the alignment should be set - not just within spec, but actually targeting certain values. None of my trucks feel "darty" on the highway. But then again - they don't drive like an Accord. Both the '92 (115K) and the '93 (185K) have had the same list of suspension parts replaced and also upper control arms. Both of these trucks have also KYB Gas-A-Just shocks. Not as stiff as your Mono-Max.

I'll look back and see if I can find the discussion thanks. I wonder if the stiff Monomax shocks are just amplifying worn suspension bits like the lca bushings. I don't remember if I was having this issue with the worn oem shocks as I replaced them soon after I bought the car.

 

[TheMole]

Posted a short vid on youtube that I took from my phone which shows how the steering reacts over a bumpy street. I had to correct the steering a couple of times to the left or I would have veered off into the sidewalk. Hopefully the vid was able to capture what I'm describing, but will try to take a better one soon.

https://www.youtube.com/watch?v=ecDMkUNYOsw

 

[nckwltn]

Posted a short vid on youtube that I took from my phone which shows how the steering reacts over a bumpy street. I had to correct the steering a couple of times to the left or I would have veered off into the sidewalk. Hopefully the vid was able to capture what I'm describing, but will try to take a better one soon.

https://www.youtube.com/watch?v=ecDMkUNYOsw

how much play do you have in the steering wheel? I don't have to turn my wheel a degree or two in either direction before the wheels react.

 

[TheMole]

how much play do you have in the steering wheel? I don't have to turn my wheel a degree or two in either direction before the wheels react.

The steering wheel feels pretty tight and the wheels seem to react as soon as I turn it. I'll try it out at low and high speeds on my commute tomorrow.