Steering: Low sped twitch

[VolvoformyStaffies]

Hope there are some ideas out there my problem. A search did not reveal anything.

The problem.
At low speeds, up to about 20-30 mph there is a pronounced twitch or pulse in the steering wheel, it kicks about 5-10mm and won't be stopped. At higher speeds it disappears. The frequency is road speed dependent. No bangs or rattles on the road or speed bumps and is only felt when going strait ahead, disappears on even a slight corner (about 25-30 degrees on the steering wheels. Car pulls to the left even when there is no road camber. Even correcting for the pull to the left can reduce / eliminate the pulsing. It does not seem to be there on braking.

The problem only appeared after I replaced the track rod ends on both sides

It has been suggested that this could be a broken tooth on the steering rack but I think it is the fact that it is road speed related and the cost and fitting time for a new rack that makes we want to rule out other possibilities

I have an RHD 02 V40 1.9 Diesel with 125,000 on the clock
I have just replaced both track rod ends and had the front wheel alignment checked and checked all tyre pressures before doing a test drive to check.

Any help would be appreciated.

Many thanks

John

[pierremcalpine]

My mother-in-law's Lexus did this and I was convinced it was the track-rod end but it turned out to be one of the wheels which was not balanced. I felt it anywhere between 10mph and say 30mph and it was a pronounced twitch in steering. A rebalancing cleared the issue right up.

[Antz]

Check everything like wheel alignment, worn bushes in the front end, tyre wear, uneven size tyres, unbalanced wheels, bent wheel rims (spin a bare wheel on a balancing machine and it should be neutral).

[VolvoformyStaffies]

Thanks for the suggestions. I am doubtful that it is a wheel balancing issues as it happens at really low speeds - like under 5 mph. It does not feel like the wheel is running out of true and I was told that the alignment was fine.

Will keep looking
John

[VolvoformyStaffies]

Originally Posted by Antz

Check everything like wheel alignment, worn bushes in the front end, tyre wear, uneven size tyres, unbalanced wheels, bent wheel rims (spin a bare wheel on a balancing machine and it should be neutral).

Thanks Antz.
Bushes and tracking checked an no movement, slight float on drive shaft but I can't see that causing the problem. As noted above happens at very low speeds so I don't think it is a wheel balancing issue. Similarly the problem only appeared after replacing the track rod ends, though I can remember what made me check them to start with.

So there has been no change of tyres and wheels were balanced before the track rod ends were done though this was a couple of months before.

A bent rim seems possible but I would expect that the effect would be felt at all locks and it doesn't. Looks like damage to the center of the steering rack is all that is left - unless of course there is a different view out there.

John

[pierremcalpine]

I think you are probably right (it not being wheel balancing). Just for the hell of it though, try switching the wheels around (front back) to see if that makes a difference.

[happy diver]

Originally Posted by VolvoformyStaffies

The problem only appeared after I replaced the track rod ends on both sides


I have just replaced both track rod ends


the problem only appeared after replacing the track rod ends


the track rod ends were done

Could it be a track rod end

Is a track rod end(s) installed upside down

[rkeegan]

I had something a little more severe which happened at low speeds below 30mph at the rear. It used to shake the car quite badly from left to right at about wheel rotation speed but disappeared once moving above 30mph. I checked everything and couldn’t see anything wrong. Jacked the car up and spun the wheels. Everything seemed fine. In the end I decided to change the one rear tyre as it was 15 years old and due for replacement. Problem cured. Speaking to people it appears the tyre can start to fail in the ply/banding construction thus causing distortion and consequential “wobble”. Try swapping your tyres as already suggested front to back and see if the issue moves with them.

[cheshired5]

What's the level of your pas fluid?
Also describe the colour and smell.

[ma70]

I'm wondering, has a wheel been refitted with a lump of dirt/corrosion trapped behind it, or between disc & hub? Or even has one of the discs been damaged/cracked? a brake pad catching a damaged disc would cause a twitch. Could also be driveshaft related if the CV joint is badly worn but you'd surely know this by the rhythmic clunking noise when the steering is locked over for parking etc...