AHC Clunking?

[DubR]

I've been trying to figure out the source of a clack/clunk/rattle that is getting worse and occurs when I drive over rough road at low speeds. I've scoured Mud for leads and gotten some good feedback on one of my prior posts on this issue. I took it to a new garage to get a fresh perspective today. The tech was convinced that the sound was coming from my AHC "shocks" (he understood what they were). He bounced my truck while it was up on a lift and had me feel the shock, which did present a clicking as it went up and down (but definitely not the prominent noise that I hear on rough road). He thought the issue was internal.

So, I guess my questions is: has anyone heard of internal problems with the "shocks" that could cause a VERY noticeable sound?

Thanks.

 

[SteveH]

My old/high miles shock mount bushings have wear/play in them and I know this contributes to clunks/rattles on rough roads.

I'll create a separate thread for this, but the axle-mounted mounting hole (left side of truck) for my Panhard rod is egged out and the axle now moves laterally (not great when you're towing on a windy road) and when I back out of a driveway, I hear a clear clunk from this.

Here's how you test for this - have a buddy push in and out (with vigor) on the top of the left rear wheel, while you look under the truck at the head of the Panhard rod bolt. The bolt head on mine moved laterally. The bushings are fine - it's the hole that is too big, due to wear.

 

[uHu]

It's likely to be the shock bushings. As they are always pressurized and load carrying, they wear out faster than on non-ahc shocks, and they are harder to diagnose. Lower the truck to Lo first, then jack up on frame or front centre jack point, a bit, to get som slack. (Altho' an experienced eye will see it).
Other common slam-dunkers are the anti roll bar bushings and links, or ball joints..

 

[DubR]

It's likely to be the shock bushings. As they are always pressurized and load carrying, they wear out faster than on non-ahc shocks, and they are harder to diagnose. Lower the truck to Lo first, then jack up on frame or front centre jack point, a bit, to get som slack. (Altho' an experienced eye will see it).
Other common slam-dunkers are the anti roll bar bushings and links, or ball joints..

Thank you. I appreciate the help. What would the “inexperienced eye” look for? And while I’m outing my ignorance, where’s the center jack point (center of axle?)

 

[IndroCruise]

Thank you. I appreciate the help. What would the “inexperienced eye” look for? And while I’m outing my ignorance, where’s the center jack point (center of axle?)

Two Page extract from FSM showing Vehicle Lift and Support Locations for Independent Front Suspension (IFS) chassis:

 

[uHu]

When you get the pressure off the shock, i.e. that it's not doing any truck lifting anymore, it's easier to attempt to move the shock end to see if there is any give in the bushing. Use e.g. a huge screwdriver or a crow bar thingy. Even jacking up and down might reveal movement. You can jack up the whole front, place on stands under frame, take off wheels, and use the small truck jack to move the A-arm up and down. You will need some support under it in any case if undoing the lower shock mount.
It is possible to change the bushings with the shock still fastened at the top, if you have one of those 5-10 ton C-clamps. You might still have to cut the outer ring of the bushing to get it out of the shock, if rusted/stuck. Carefully.