1983 W900 Dash problems

It may not be the instrument cluster, I would check under the hood and along the firewall, also would check the cab mounts, battery hold downs, thing of that nature. Sounds like that can be very frustrating as they transmit through the cab and chassis.

 

Check your front leaf spring bushings.

 

Probably the hood. Check for shiny spots where the hood meets the cowl and check the rubber bumper pads that support the hood.. I've had doors rattle too. Could be spring hangers, but I think you'd feel it in the steering wheel. Like Alaska says, that Ka-knocking can be transmitted through the cab from somewhere else. Close the hood on a wadded up rag, and see if it still makes noise.

 

My W900L experience -which I have about 18yrs of- says Semi-Retired probably hit the nail in the head. When dash itself is loose you can carefully snug screws forward near glass and help that, but at worst it generally just creates an anoying squeak when you hit a bump. When front cab supports wear/flatten out the cab will slightly nosedive which allows the hood to bump cab. I replaced my hinge mount bushings and that raised the front of hood up considerably more than I would have thought. Had to adjust hood forward as far as it would go to keep it from bumping. Also cut out some rubber donuts and dropped them over the rubber guids back by air cleaners because it was binding when you first tried to get it started coming up- kinda stuck closed. None of it made any sense to me until I had the sleeper off and changed those bushings back there. Went to put boot replacement boot in and it was alot tighter at top than bottom. Had stacks off so I got out and compared the gap between bunk and cab. That is when I figured it out. Gap was about 3/4" wider at top than bottom. Replaced front bushings under cab. Problem solved, except I need to move hood back just a fuzz. It opens much easier and sets on the cowl like it si supposed to now. Funny thing is I never replaced rear bushings under cab because dealer was going to have to order them and I didn't have time. Everything seems to line up good as is. If you decide you want to change the front ones, let me know and I will give you detailed instructions. Sorta a trick or combination to doing it with cab still on truck. No big deal. Like 18 bucks a side at kw for bushings.

Tilt column U joints are another annoying thump, but u can feel it in wheel. Changed underhood u joints twice before I figured out the main problem there was - the joint in the column itself.

 

What type of engine and year check flash codes than google code to find problem I suggest registering on cummins quick serve online it is free and it will take your engine serial number and than you have all manuals for free!!!! there are several ways now a days to get flash codes if you have an info center on the cluster there a control on right side of sterring wheel on the column. if not look for a switch labeled DIAG this will flash out codes via check engine light . Or put cruise switch on and use accl/decl switch to flash out code. count the blinks this is your fault.
The fault code will flash in the following sequence:
First, a WARNING (yellow) light will flash . Then there will be a short 1- or 2-second pause after which the number of the recorded fault code will flash in (red) STOP. There will be a 1- or 2-second pause between each number. When the number has finished flash ing in red, a yellow light will appear again. The three-digit code will repeat in the same sequence.
The lights will continue to flash the same code until the system is told to do something else. To go to the next fault code , move the cruise control/PTO switch momentarily to the RESUME/ACCEL position. You can go back to the previous fault code by momentarily moving the cruise control/PTO switch to the SET/COAST position. If only one active fault is recorded, the system will continuously display the same fault code when either the RESUME/ACCEL or SET/COAST switch is depressed.

 

Sorry wrong page all use full info though. I'd check the dash inbetween window like w91 allready suggested

 

shock mounts and front cab mounts would be my first check.

 

Excellent, thanks for the update!