Steering Problem

[goser]

I don't know if these are related, but every once in a while backing out of a parking spot I get a clunk from the front end, and when travelling at a good clip and usually on a curve to the right it feels like the truck skips or hiccups briefly toward centre. When it happens it freaks the hell out of me but the shop couldn't find anything loose/failing. Any suggestions on where to narow down the search to would be amazing.

[taillight]

What year, make, model? It could be the EVO sensor(Electronic variable orifice) on the steering column.

[goser]

98 Jimmy 4X4

[old_master]

1998 S/T series is not equipped with EVO. What you are describing is called "bump steer". It is caused by the steering linkage not being level with the chassis. Most commonly caused by a worn or improperly installed idler arm.

[goser]

Thanks, I'll double check the idler arm.

[goser]

Grasping the centre link i was able to move the idler arm up about 1/8", which seems to be within spec. At the pitman arm I was able to move the centre link and pitman post an 1/8th as well. Should there be any play at this joint?

[old_master]

In a perfect world, there should be no movement. Any percievable vertical movement of the idler arm or pitman arm will affect toe in, which will affect tire wear. The test for uneven steering linkage, the cause of bump steer, is to measure from the outermost point of each end of the center link, vertically up to the frame. The closer the measurement side to side, the less bump steer. To adjust: Loosen the bolts attaching the idler arm to the frame, move the center link where it needs to be, tighten the bolts, and re-measure. The holes through the frame are purposely made larger specifically for this adjustment.