hey dudes,

96 disco 95k.. new to me. bone stock. (slight fender trimming to fit 30.5"s)

as i've said before, new to this make and model (but not to vehicles..). i've basically been taking it apart (got a Zuki DR 350 as DD...wonderful in the Colorado winter. not.) , running through everything to get familiar.

when i bought the vehicle ($5k, thought it was a good deal) it was essentially immaculate. got it from some dude in Aspen who had just used it as a soccer-mom truck. but it was obvious it hadnt had routine maitenance or anything.

the ABS was shot. i took a looksee at both front wheels. sensor was busted on the driver's side, and there was a bad master cylinder on the passenger side. managed to get a good deal on parts for both ($200 for a sensor! f'ing dealership wanted something like $500). so ABS is working now. although i promptly pulled the fuse, since i dont like the way this one feels when i take it wheeling. but might be useful for the snow/ice whatever.

ANYWAY.

now i've got a weird shimmy in the steering. usually at highway speeds. 50-70 mph. it's got a little wobble, and when i release the accelerator quickly it doesnt track right and pulls the steering wheel to the left. nothing dangerous or anything, but enough for me to be a little concerned. again, running relatively new 245/75s, so no weird wear on them or anything.

now, i've checked the steering link, columnm, steering box, steering damper, front dampers, panhard rod bushes, tie rods. everything obvious.

everything looks fine! one of the bushes on the tie rod was worn, so i replaced it. didn't do a thing.

the ABS valve fuse is disengage, so i dont see how it could be affecting it. the master cylinders, rotors, calipers, they're all in good shape. i installed the sensor using a dealership manual as a reference (hey.. i'm new to these trucks), and everything checks out, as far as the ABS goes.

the track rod and drag links are in fine shape, too. wheel bearings are fine too, as far as i can tell. I've been told Rovers always have a little play in them. more than say, a Jetta.

WTF?

the only thing i can think of is that the swivel pins are screwy. there's no real play in them or anything, but i talked to a local guy and he said the bearing uses a spring in the housing as a balance. and it's "pre loaded". i've looked, and the swivel pins do have shims in them and whatnot. do they have to be re-shimmed? everything *looks* Ok.

i'm not ready to return to the dealership with my tail between my legs after I told them to F-off when they wanted 500 bucks for an ABS sensor.

any ideas/insights?

Felix

uh, wheels out of balance?

the new wheels/tires (BFG MTs on NATOs) were installed professionally very recently (last month or so), and i haven't done any hard wheeling.

I dont have any reason to believe they're out of balance..

there's no vibration or drifting other than under these specific conditions. the steering wheel sits fine, except under the condition i listed. doesnt pull under braking or acceleration. no weird inconsistencies in the hum of the tires.

still sounds like tires out of balance... its possible that since the wheels/tires are so new that the tires have spun on the rim some since initial installation. if they were professionally mounted/balanced then they should have some sort of balancing guarantee... i would bring them back and have them check the balance for free.

do you recall if it did the shimmy wiggle thingy before you got the MTs put on?

my buddy does have a spin balancer that does static and dynamic tests... i'll try to see if i can swing by his place tomorrow.

i have an old bubble balancer, but that didnt turn up anything.

i read somewhere that some new tires suffer from "radial force vibration"... just imperfections in the ply or splices of the tire.

if i can't diagnose it I might just go back to the tire place and see if they dont have some sort of lemon law. although im not convinced it's the tires.

do you recall if it did the shimmy wiggle thingy before you got the MTs put on?

no. :(

i did the brake/ABS work after i purchased and installed the new tires.

which was pretty stupid, in retrospect.

i would bring them back and have them check the balance for free.


yeah, gonna do that this week regardless.

but i thought i'd check in here first to see if it's a common issue.

Have you tried the front to back tire swap? Sometimes solves the shimmy issue and identifies the tire / wheel as the culprit.

KAA

i didn't think it would matter, since the tires have about 500 miles on them.

but i'll try anything at this point... gonna be a busy day tomorrow :D

The fact that the truck feels spooky when you lift off the throttle may suggest that the radius rod (leading arm) bushings have gone soggy and the castor angle is changing from positive to neutral,or even negative if the suspension is higher than stock.There is no spring in the swivel pins. only 1948 to about 1960 series had springs and tapered bronze and steel top swivel bearings.
Bill.

The fact that the truck feels spooky when you lift off the throttle may suggest that the radius rod (leading arm) bushings have gone soggy and the castor angle is changing from positive to neutral,or even negative if the suspension is higher than stock.There is no spring in the swivel pins. only 1948 to about 1960 series had springs and tapered bronze and steel top swivel bearings.
Bill.

I agree with Bill but will add that swivel preload is such a simple process that at 95K it may well be worth it.
(rant on) folks frightened of what appears to be hard, shy away from swivel preload and spend many dollars on bushings, tie rod ends, tires, etc. when swivel preload is a near free process that doesn't take all that long and should probably be done earlier in the process(rant off)

Also take a look at your universal joints. Again, at 95K, they need to be replaced and they are fairly inexpensive. The import joints are OK if you keep an eye on them and don't expect them to last 100K.

Peace,
PT

To supplement what Paul wrote, if you suspect swivel preload but are feeling lazy and don't want to do it the right way :flipoff2: just take off the smallest shim off each side and go for a drive. if its better, then get it back to your garage and set the preload correctly.

also wheel bearings.

Or since it has been 500 miles loose lug nuts

Panhard rod Bushings?

Keith
www.rovertracks.com

check the bolts and bushings that hold the front radius arms to the frame.

if they are loose or worn, transitions on or off the gas will cause scary wandering and slight vibration.

prolly the tires though!