OK, this has been bothering me now for almost 2 yrs. When I stop in drive there is a very bad drone. If I leave it in drive and set the e-brake, take foot off of brake pedal then the drone stops. If while slowing down I go to neutral and then complete the stop then I have no drone. While stopped in neutral if I then pull it into drive the drone may or may not be present. But if it's not and I slowly roll forward and then stop then I get the drone.

I'm pretty sure I need to have the rear brakes serviced because when I try to take off from a dead stop they feel like they are sticking and I get a clunk from them. I don't think they have ever been serviced or looked at.

Is there anything else that could cause this drone/vibration that I have. Could it be the exhaust rubbing?

One theory that I have made up - Maybe stopped and under the load the motor mounts are old enough that the motor is rotated to the right or left enough so the downpipe is rubbin on the frame? Although working on it alone I'm not sure how to test that theory. And I don't know which way the motor turns...

Please give me some ideas.

thanks,
Paul

I'd be looking at that 4" exhaust for rubbing somewhere.

i know my custom 4" exhaust is rubbing a lil bit and if the revs are slightly over idle itll make a drone vibration.... gotta get back down there and see whats up

check your downpipe if it is aftermarket. my 3 inch mandrel bent downpipe was touching the frame right by the passenger side front wheel and i got that horrid drone only when stopped with my foot on the brake, and it drove me nuts. what i did was a took a prybar and gave it a little push and it moved the pipe off the frame by maybe 1/4 of an inch so it doesn't vibrate anymore. i just don't want to take the pipe out and dent that part in myself but that would work too.

EDIT: to check your motor mount open the hood and get the best vantage point so that you can see the engine from the cab. put the truck in Drive hold the brake to keep it from moving and step on the go pedal lightly and watch the motor flex. in drive the motor will flex towards the passenger side but only a tiny bit. in Reverse to check the passenger side motor mount it will flex to the drivers side, again it should only be a tiny bit. also if your motor mounts were worn out you'd hear the engine fan hitting the shroud and that sound isn't hard to miss.

using a pry bar on the downpipe won't damage or move the turbo around? I'd hate to brake something above the downpipe.

thanks for the suggestions so far. Hopefully I've over analyzed this and it'll be a quick fix.

using a pry bar on the downpipe won't damage or move the turbo around? I'd hate to brake something above the downpipe.

thanks for the suggestions so far. Hopefully I've over analyzed this and it'll be a quick fix.

While duplicating the noise (hum/drone), have someone apply pressure to the tailpipe with their foot (preferably with a shoe on it) and see if it goes away.

You may also want to check your air box. The one on my 96 has decided it wants to make a heck of a "racket". I wasn't sure what was going on at first, but finally traced it to the air box.

Just a thought.

hopefully tomorrow I can get someone at work to touch the exhaust and see if the noise goes away or changes.

thanks for the different ideas

Just a thought, since you mentioned you only hear the drone with the brake pedal applied: maybe something is wrong with your hydroboost system or the power steering pump? The brakes are boosted hydraulically with the power steering pump on these trucks.

If you have aftermarket nerf bars, check the LF mount for rubbing on the ground strap bolt, if so add a few washers.

Edit: As for the rear clunking... the slip yoke is binding

Drone problem has been solved! Downpipe was touching the frame. For $10 the local muffler shop heated it and bent it in slightly so it's no longer a problem.

Now to solve the clunking problem. I have a two piece drive shaft, It looks like the back shaft that connects to the axle does move. As luck would have it there is a grease fitting there - take it for a drive tomorrow. Fingers crossed!