I have a '99 Ram 4x4 quad cab. Sometimes, does not happen very often, i hear a knock that sounds like its coming from underneath the cab. I think it only happens when i decelerate or brake. Does anyone know what this is???

Thanks

 

does it sound like the drive shaft is hoping up?

 

what sound would that make?

 

just a clunk after you let of the gas when going around 60.

 

Check your sway bar links. They attach the sway bar to the frame on both sides. They look kind of like a tie-rod, except vertical, they mount to a bracket on the frame on top and have ball & socket joints on the bottom connecting it to the sway bar. On both my '97 and '98 they went bad, the ball part of the joint wears out and clunks around in the socket until it comes out of it. If they are bad, you can get replacements at just about any auto parts store. You may need a big hammer to get the old ones out. Also, be sure that the new ones are the same. Every place I bought them from had one of the two, and it turned out to be the wrong one.

It could also be the bushings for the sway bar where it mounts to the frame. Factory ones are pretty expensive for a piece of metal and rubber. I bought a set of universal polyurethane ones from an auto parts store, I think they worked much better.

It could also be the track bar. You may call it something different, but it's on the 4x4 Ram's. It's a bar that runs from side to side above the front axle that attaches to the axle on one end and the frame on the other that keeps your axle underneath your truck.

I've replaced all three of these things on both of the 4x4 Rams that I've owned, so I know that they do go bad. I can't really remember whether it was speed or breaking or bumps that caused the clunking, but I know that's how I realized there was a problem.

I suppose it could possibly be one of the ujoints on the drive shaft. Actually, hearing you say that you only hear it when you let off the gas leads me to think that. Does it clunk any worse than normal when going between reverse and drive? That would point to a bad ujoint too.

 

It only clunks when i let off the gas, last time i heard it was when i was going around 30 - 40mph. It does not happen very often. It does not clunk in reverse. The trac bar was just replaced.

Thanks