What is this noise????

[Wallybanger]

My god... I'm getting a little overwhelmed and I'm wondering if I made a mistake buying a dodge... . This truck is making a really strange noise and I have no idea what it is...



the truck is a 93 Dodge W250 with a cummins and auto transmission.



So I'm driving down the highway, cruising at 100km/h and this noise starts coming from the truck. I had heard it before but I thought it might have been the road surface... now I know for sure that it is definitely not the road surface.



It sounds like all 4 tires are riding on those rumble strips on the edge of the highway. It's loud. I was thinking that maybe a mudflap got stuck on one of the tires or something but there is nothing touching the tires.



I checked my front hubs and they were cool to the touch. my front axle was cool to the touch (which it should be since I was in 2WD)



Rear axle was slightly warm but obviously well within normal operating temperature. I didn't pull the dog dishes off so I don't know if the rear hubs were hot, but I'm assuming not.



The noise would start whenever I hit a sharp bump. It would start every time I hit a bridge with a bump where the asphalt meets the concrete. It would stop as soon as I dropped below 40-50km/h, and then I could resume cruising at 100.



I grabbed my rear drive shaft and it feels ok but there is a very slight movement on the forward U-Joint. like, I couldn't see it moving but I could feel a bit of a movement.



I tried turning the engine off, noise didn't stop

I tried putting it in Neutral, noise didn't stop

I tried turning the OD off, noise didn't stop





So the only thing I can think of is that either some of the wheel bearings are gone... which doesn't make sense (cuz hubs weren't hot) or there is a driveline balance issue due to a bad u-joint...



Is it possible that a sharp jolt from a bump could throw the drive shaft out of balance and then when I slow down to under 50 it's able to realign it's self?



I hope it's nothing serious. I need to figure this out because I don't want to blow something up or lose a drive shaft in the middle of nowhere.



It started happening as I was driving from Nanaimo to Campbell river to visit family.



So I drove back 2hours from Campbell River to Nanaimo and it didn't make the noise once...



Took the ferry from Nanaimo to Horseshoe bay and then to Gibsons to see a friend. Drove up in the hills to meet him at a gravel pit where he was shooting. On the way back down the logging road it made the noise twice while hitting bumps in the corners. Then nothing.



Took the ferry back to horseshoe bay.



It did it again twice while crossing bridges in Vancouver... . then it happened again twice on the whole trip from Vancouver back to Kelowna... . So the problem is a little difficult to reproduce... . Otherwise I would have caught it on video. Think I'm gonna mount the GoPro to the front axle and drive around to see if I can catch the problem on tape.



I have been posting in some other forums but haven't been able to find anyone who can positively identify the problem. Someone suggested the death wobble but I don't think that's it. Nothing like the videos of the second gens and i can't really feel anything through the wheel (although I do have a bunch of slop in it).



Thanks in advance

 

[cerberusiam]

Check your exhaust system tomake sure all the hangers are good. Make sure you cannot move the pipe anywhere wher eit is possible to touch metal and check the down pipe mount on the trans to make sur eit is tight and the rubber grommet is still there.



When the exhaust touches metal ANYWHERE it make syou think awheel is getting ready to come off.

 

[DVolk]

Pull your rear diff plug and see if there is oil !!! my guess its a rear axel seal that you dont see it happend on my 92 before . Also check your universals

 

[HBarlow]

Members here would like to help you but you're not giving us much to work with. It's very difficult to diagnose a problem we can't hear and might not describe exactly as you have.

I think your best bet would be to ask another TDR member who lives near you in BC to meet you somewhere and ride in your truck. He may know exactly what is causing the noise you're hearing.

 

[NIsaacs]

It is probably dry, binding u-joints. Usually you won't feel any slack in this case, they will usually be warm to the touch after a good drive. They should be cold. An intermittent rumble sound is what you will hear or feel.



Nick

 

[JLEONARD]

I would also check driveshaft u joints.

 

[Greenleaf]

Center support bearing



You don't have Pastor Bob's old rig?

 

["Mad Max"]

I'd also second the thought of a loose exhaust system either resting along the driveshaft or frame, possibly between the transfer case and frame.



What you describe does not sound like a 'normal' problem, which means it's likely a fluke - real obviously, but not common or re-occurring. I'm also wondering if your u-bolts are tight - it's a long shot but maybe the axle is shifting within the perches and causing some sort of out-of-phase issue with the ujoints.



Lastly, bad (or going bad) carrier bearing, or one of the two bolts holding it to the frame crossmember are loosening up and allowing the shaft to whip about a bit.



- Sam

 

[JLEONARD]

it's a long shot but maybe the axle is shifting within the perches and causing some sort of out-of-phase issue with the ujoints.

The axle would have to move a lot to cause an out of phase condition.

 

[HHhuntitall]

I'm gonna go with a driveshaft u-joint/carrier bearing, or a rear axle hub bearing. As it's intermittent, that points to the driveshaft. It's obviously in the rear drivetrain, as it does it when the engine is dead, so it has to be something that's moving, or moving against something. The exhaust is a possible culprit, but I'd think it'd be more regular, as it would be with an axle problem. If you're feeling in slack in the u-joints, that's your culprit, I'd wager.

 

[DVolk]

Take it to a tire shop have them do a look if nothing else most do it for free

 

[stoneagemaxx]

i know this is alot more common on the ball joint fronts but possibly kingpins? my 92 W did like what your saying hit bump lil shake/vib hit another gone mine usually dident correct itself at lower speeds tho