92extle

Hey guy's. Sorry if this is an old topic, but I tried a search and didn't find much.
When leaving from a dead stop, with the wheels turned full to the right, I almost always get a knock. Not every time though. Fairly loud and at steady intervals. Say three times in the time it takes to make a corner. When turning left it has never happened. Thought it was the limited slip so I flushed and added 250 ml of modifier to fresh 75-90.

It did seem to help some. Not as frequent now, but still happens. I'm not totally convinced it's in the diff. Kind of hard to tell if it's front or rear. Feel's like the hub is locking momentarily. Put it up on the hoist and front end is tight except for some very minor play in the front half of the drag link. Kingpins are tight and hubs work fine.

Sorry for the long post but it's getting annoying. Thanks for any info.

cLAYH

Is it a 4WD? If so I would check the front axle shaft ujoints. Any unusal vibrations on the highway? If you do I would remove the driveshafts and check the u-joints and while its off grab the pinion yoke and see if there is any play in/out or up/down.

What kind of knock is it? Fast/slow, one single konck? Clicking/thumping? Front or rear?

Mexstan

As cLAYh said. Also, have you tried doing this in reverse?

92extle

Yes it is a 4x4. Axle universals felt fine, without removing to thoroughly check them. Hard to tell for certain if it is front or rear. No it doesn't do it in reverse. And it won't do it in 4 wheel drive either. It is a single, momentary knock. No vibes on the highway. Thanks for the input. Mark

cLAYH

I would have someone turn the steering wheel from full left to full right while you go under the front end and watch the steering linkages, ball joints and tie rod ends. Look for anything rubbing or sticking and then suddenly releasing. Also check the steering box mounting bolts and see if there is any movement against the frame. Have seen some 1/2tons with cracked frames around the steering box that made strange noises.

Also have your assistant try just moving the wheel back and forth about 1/4turn(basically taking up the slack) while you watch the linkages, this will make it easier to detect any excessive play in the linkages.

92extle

Yes I was thinking it could be the steering box. Previous owner had a big set of tires on it. I'll let you know what I find.

92extle

Replaced the drag link, pulled both axles and replaced u joints. Frame to box OK. Still doing it. Must be in the rear somewhere. ????

Mexstan

With all that work you did , did you check the wheel bearings? Are you sure that they have the right amount of preload?
Have you tried jacking the front wheels up and then checking for movement at the 6/12 o'clock and the 9/3 o'clock positions? With it jacked up place acrowbar under each wheel and see if you can induce any movement in the wheel.
How are your shock bushings? Take a real close look at each of them.

Alec

Did you check the king-pin bushings (top) and bearings (bottom) when you had it apart? My upper bushings were shot, but when I checked things out before disassembly, I couldn't be sure anything was wrong because the spring pre-load is so high on the upper bushing. Just another thing that can go wrong.

Good luck finding the noise.