Front wheel vibration

[mduark]

All,

A little back ground. I have my second 93 RRC that has 55K miles on it. The previous owner had large AT tires on it as well as installed ARB lockers front and rear. I replaced the AT tires with highway ones and have since noticed a distinct vibration coming from the front wheels. It is usually around 40-55 when coasting for a bit and slightly giving more gas to accelerate and generally goes away above 55-60. If I slam the gas I don't notice it. I've replaced the bearings (not the races though) and that seemed to work for a bit. I went back in a re-tightened them to no avail. Never had this problem on my other RRC, was always a straight forward maintenance task for 195k miles. So now I am at a loss, I'll have the front tires rebalanced in the morning. I looked over the old bearings and nothing seemed terribly worn or damaged (although not an expert). Should I pull the races? Or is there another wear part that I am over looking? Could this come from the locker possibly not being installed and loaded correctly? Or something else? Seems like it should be an easy fix and I'd rather not take it somewhere and have the guy roll his eyes at me but for whatever reason I am at a loss and feel that I am over looking something. When I replaced the bearings it seemed to help for a bit as well as when I re-tightened them, but I'd like to not do that every weekend.

All helpful hints are welcome.

Thank you,

Mark Douglas
93 RRC 195K
93 RRC 55k
82 Series 3 200 TDI
70 Series 2a

[REDrum]

Check front 3rd bearings

[o2batsea]

With the front wheels off the ground and the truck firmly secured from falling (jackstands) try to wiggle the wheel in and out (top/bottom not left/right). If your bearings are properly adjusted but you still get some play, then your swivel pins/bearings are shot. Larger tires can certainly shorten their lifespan. Too little pre load on the swivels can lead to vibration. The only remediation is a complete rebuild of the swivels with new top pin (ABS? the new ABS pins come with new sensor bush and o rings so you don't need to buy them separately), Railco bush, lower pin and bearing. Might as well go on and do the swivel ball seals/retainers (check for pitting on the chrome surface) and do the one shot grease thing. Also a good time to inspect the CV joints for wear. If they are clicking it's probably cz they are dry, or worn out. Or both.
Second possibility is the tie rod ends. There are 4 of them. Also check the steering damper for worn bushings and leaking.
Range Rovers have two extra vibration damping devices. There is a donut-looking thing hanging in the middle that is a vibration damper, and on the bottom of each swivel housing is a hunk of steel bar that supposedly does something. These are not wear items but you should check them for tightness.
Good luck. Hope you don't need a complete tear down, but it might be time to consider one anyway. Parts aren't all that expensive, 'specially if you order from the UK. I think I got the whole everything for about 100 pounds or so.