Vibration at cruising speeds

[BigTim]

A question for the mechanical guru's out there. Vehicle is '03 Defender 90 Td5, approx 100000km on clock.

I am experiencing vibration / steering shudder ONLY between 100 and 110 km/h, typically when cruising on motorways in 5th. The problem does not tend to occur under heavy acceleration e.g. overtaking, but if I accelerate gently past 100 km/h I get a nasty shudder (feels like the whole car is shaking left and right) until I drop back to 95-100 (or up to about 115 :wasntme:) Vibration gets worse if it occurs on a slight bend to right.

Original wheels / tyres (Grabber AT M+S). All tyres inflated equally at 36 psi cold. No signs of rim damage - all balance weights still in place etc. Regularly rotated every 20000km. Did note an unusual scalloping wear pattern on front drivers side tyre, mostly on the inside of the tyre, not sure if that is cause or symptom of problem or unrelated.

Anyone got any suggestions on most likely causes / things to check?

Cheers.

[langy]

Front shocks ( at least one anyway). Swap tyres and see what happens. That abnormal wear pattern is something to be concerned about, especially on a 4 yo defender. If swapping the tyres cures it, then one of the first set of tyres is scalloped and will have to be relegated to off road work only. If the shakes continue, then try swivel bearing preload ( I'm presuming that your def90 is one of the last with traditional swivels ) or something is bent out of shape, the likely contender being the track rod - decent wheel alignment will tell.

[JDNSW]

If the vibration period is consistent with the wheel rotation speed, it is almost certainly swivel preload, although free play anywhere in the suspension is possible, and it may be exacerbated by faulty steering damper, wheel alignment, loose bushes on the panhard rod, loose wheel bearings, loose tie rod ends, pitman arm loose on steering shaft etc.

If the vibration is higher frequency than this, suspect the prop shafts - loose on the flanges, worn or siezed cross and bearings, or, if the front prop shaft has been off lately, incorrect assembly (the front shaft should not have the yokes in the same plane - there should be marks showing the correct position).

John

[BigTim]

Cheers guys, I'll have a look at that stuff tomorrow and see what turns up.

[hiline]

my 130 TD5 is doing the same sort of thing but at 80-90k's

i have replaced the steering damper as it was stuffed
wheel bearings replaced
tie rod ends
and bushes

i must add the steering feels alot tighter and better ;)
but the wobble is fairly violent

help also would be appreciated here :D

cheers

[Hartley]

I consistently get a wobble around 80 km/hour also in Discovery TD5.
I had hoped it was just uneven tyre wear but now I will look at the things suggested also.

[Graeme]

A question for the mechanical guru's out there. Vehicle is '03 Defender 90 Td5, approx 100000km on clock.

Original wheels / tyres (Grabber AT M+S). All tyres inflated equally at 36 psi cold. No signs of rim damage - all balance weights still in place etc. Regularly rotated every 20000km. Did note an unusual scalloping wear pattern on front drivers side tyre, mostly on the inside of the tyre, not sure if that is cause or symptom of problem or unrelated.


How long since the wheels were balanced?