Hi,
I just bought a 03 3500 Quad cab long box with the HO Cummins and 6-speed. I notice that when I let the clutch out I hear a clunk sound sometimes that seems to be coming from the driveline. I get it when backing up because I am on and off the clutch a lot being careful not to back into someone. I can reproduce the problem by putting the truck in gear and with my foot on the brake I let the clutch out and then push it back in before the engine stalls. ie: I am taking up the driveline play and loading it down. I hear a clunk when I let the clutch out and another when I push it back in again. It goes clunk clunk as I cycle the clutch pedal. I had the wife do it while I looked under the truck and I can't see where the noise is coming from. When she does it I see the engine load up the drive line and things flex on their rubber mounts (not excessively) and I hear the clunk. The truck only has 60 000 km on it and was never worked. I never hear this clunk when taking off from a stop and going through the gears. Just when I back up (maybe it's the way that I clutch when backing up) and also when I try to reproduce the noise with my foot on the brake.

Is this normal play being taken up or do I have a problem?

Thanks,
Steve.

 

Mine does this too, I think it is just normal play in the driveline. Mine really does it BAD since I have the SBC FE in mine and there is no slipping it.

 

i can make that noise too... i think it is the clutch dampening springs acting on all the backlash in the drivetrain [gears in trans, t-case and diff backlash] it is a little annoying, but for the few times it happens, i don't worry about it [most of the time i hear it is when driving forward in the city and i am just accelarating and the one in front decided to stop so i get off the throttle and on the brake and clutch quickly]

 

Thanks guys. Besides testing for the noise I only hear it under normal driving when backing up and I am on and off the clutch. I can see how it could happen in city driving when having to stop quickly and get on the clutch. I haven't driven in the city yet, to big

Steve.

 

What your hearing is the transmission being picked up by the engine as you let the clutch out.

If you have the .wav file that is a recording of the cummins engine starting, you'll notice that same sound on the .wav file. I use the wave file as the startup for my computer instead of the normal windows music. I know when it starts like that it will be ok all day.!!!

If you want a copy of it, e-mail me and will forward.

Dave

 

None Here..... ...houtex

 

Thanks for the offer Dave. I would like to hear the .wav that you have. I tried to email you but your email address is not puplic or the system would not allow me to send you an email. You can email me the file at:

pringles@nortel.com

Thanks,
Steve.

 

Think I fixed the e-mail problem. Will send you the .Wav file shortly.

Dave

 

what rpm are you shifting at? on my 01 i was babying it for unknown reason and shifting at 2000rpms empty and it was clunky so i just learned to live with it. then i was tryin differnt rpms levals and started to shift at about 2300 to 2400 rpms and to my supprise it was alot smother and it did not bog down any more.

 

I think I'm shifting at about 2000 RPM or so. I don't really rev it that high before I shift. There seems to be so much torque that I just eat through the gears quite quickly. I never get this clunk while driving forward, only when in reverse when pushing the clutch in and out a lot easing the truck back and checking that I am not backing into someone.

Steve.

 

When I read the first of this thread, I figured it was due to a bad engine or transmission mount, or possibly a drive shaft/U joint issue...

Mine doesn't clunk like that?

 

i used my friends 03 to tow and it makes the same sound