Bad noise when I am not pushing the pedal

[maybedodge]

2012 dodge 3500 SRW diesel mega cab. I've owned it for 3 weeks. 200,000 kms on it and was a one owner truck before me. 65 year old man who seemed to be a really decent guy and didn't abuse it.

Truck has been great until tonight. I was hauling a 4000lbs water tank in the box. It's a 15km ride home. I noticed when I got up to around 80km/hr. The noise seemed to go away after a couple seconds, but then when I touched the pedal, I got the same noise again for a few seconds and as long as i kept my foot touching the pedal, the noise went away.

As I got closer to home I think it got worse. Seemed like if I didn't have my foot on the pedal it made the noise. It didn't go away after a few seconds.

The whole way home is a 100km/hr highway. But when I slowed down to turn into my driveway it seemed like the noises stopped when I got under 80km/hr.

I thought for sure u-joints on the axle. But they feel fairly tight. The axle going to the front diff has a tiny tiny bit of play. The axle to the rear diff seems all tight, except that joint in the carrier bearing. It has a rubber boot around it and has some play, but I am pretty sure it's supposed to be able to move?

I've always been a GM/duramax guy, so I'm just learnging this truck.

I won't havbe time to drive the truck without any weight in the back to see if that's the issue until tomorrow night.

I could be wrong, but I don't think its the tranmission since when I was on the gas it was fine and the noise wasn't happening between shifting points.

Any ideas?

 

[Oliver Closehauf]

when you say foot on the pedal, are you saying just enough throttle to load the transmission or just enough to unload it?

say you are going down the road at 100 KM/hr. The engine is loading the transmission keeping the truck at speed. You take your foot off the gas to slow down and there is period between forward load and engine braking where there is no load.

Is the noise in that no load gap? Or is it on the load or engine brake side?

 

[maybedodge]

now that I think about it... I think I heard a clunk when shifting into reverse a couple times. I thought it was a couple of blocks of wood in the bad falling over/ getting knocked around. But I am now thinking it was a mechanical clunk.

To me that seems like u-joints.. But they feel tight.

With my GMC's they were deffinitely looser before you'd notice any symptoms. The front u-joints were often a tiny bit loose and no symptoms at all. I'd replace them as soon as there was a bit of play anyways.

 

[maybedodge]

when you say foot on the pedal, are you saying just enough throttle to load the transmission or just enough to unload it?

Noise went away when i put just enough throttle to engage the tranmission. If that makes sense? I just had to barely touch the pedal.

say you are going down the road at 100 KM/hr. The engine is loading the transmission keeping the truck at speed. You take your foot off the gas to slow down and there is period between forward load and engine braking where there is no load.

ya that sounds right. It's that space of time when you take your foot off the pedal to slow down and the engine braking is no load. I think that;s what's happening.

I tried to see if braking helped when it made the noise, but I don't think it did.

Is the noise in that no load gap? Or is it on the load or engine brake side?

I'm not sure what you mean "is it on the load or engine brake side".


Thanks the the reply

 

[maybedodge]

When I bought the truck, I did see the rear diff looked to be recently serviced. You can see the stain of lube by the fill plug. Does the truck need the limited slip fluid ? I can't see it being the rear end, but ??

 

[maybedodge]

The sound seemed to be coming from under the front seat and maybe a bit closer to the front of the truck

 

[Oliver Closehauf]

Yeah, check your torque converter bolts.

Just for the record, I get the same noise. I have a rebuilt trans with a billet converter and Goerend internals and I get that same noise when there is no load. Apparently it's not a problem, just annoying as hell. I get it in park or neutral but it goes away as soon as I put it in gear. I'll hear it when coming to a stop right before I come to a complete stop. A soon as the trans starts pushing against the brakes it goes away. Or as soon as I give it gas. I took it to the shop that built it and it was given a clean bill of health. Probably sun gears or something, but you should check your torque converter bolts just to be sure they are tight and you have no cracked mounts or flex plate issues.

 

[GTyankee]

I would not rule out the differential fluid level being Low
If that is the case, the wheel bearings could be starving for lubrication

 

[shrubs]

I think the posts above by Oliver and GT have merit.

Amazingly fluid levels and/or new fluid is an easy fix that…..sometimes…. make a a huge difference. If for nothing else, as part of troubleshooting, fluid levels and fluid quality squares are verified.

 

[maybedodge]

Yeah, check your torque converter bolts.

Just for the record, I get the same noise. I have a rebuilt trans with a billet converter and Goerend internals and I get that same noise when there is no load. Apparently it's not a problem, just annoying as hell. I get it in park or neutral but it goes away as soon as I put it in gear. I'll hear it when coming to a stop right before I come to a complete stop. A soon as the trans starts pushing against the brakes it goes away. Or as soon as I give it gas. I took it to the shop that built it and it was given a clean bill of health. Probably sun gears or something, but you should check your torque converter bolts just to be sure they are tight and you have no cracked mounts or flex plate issues.

Never thought of torque converter bolts. I'll check them along with rear end fluid.

I may just pull the drive shafts off to inspect the u-joints as well. In the duramax, this sound was always be u joints. I'm guesing when I pull it off that carrier bearing and a u joint will be toast. I don't think the u joints or carrier has ever been done on the truck.

I don;t think flex plate since the noise is only at high speeds and during very specifc times.

Lol, I don;t know how this noise could be normal like yours is.

 

[Oliver Closehauf]

Maybe my noise isn't bad as yours. My noise happens standing still and no load conditions at speed. The location sounds the same. But I have no performance issues and no shifting problems or noises from the driveline (except for a mystery clacking from the alternator that comes and goes).

 

[maybedodge]

Took the water tank out of the truck and went for a drive. No noises.

I went F to R a few times in the driveway and no clunk. But I'm certain I heard it before.

Either way, I got under the truck again and yes the carrier bearing is all floppy. The rubber ring is almost gone on top of the bearing.

New carrier bearing and u joints on order. Truck has 200,000km on orignial u joints so might as well put some with a grease zerk on it.

I'm sure that's my issue. I've never had a truck with a carrier bearing before so I this noise is new to me.


I will check the torque converter bolts and rear end fluid as well this week. Been very busy since buying the truck. I will go through it back to front and do all fluids and filters. PRevious owner just updated the service, but can't hurt

 

[maybedodge]

Just an update.

I did the rear axle. The carrier bearing was toast and the once it was off, the ujoint that goes right against the rear diff was tight/stiff.

I figured no big deal, I've done lots of ujoints.. Was I ever wrong lol. My god it took forever to get the old ujoints off. I ended up using the grinder on most of them so I could pound them in instead of out. Pounding them out wasn't working since the portion of the cup inside the ears of the unoint was rusty and therefore not wanting to push through the hole on the ears. And the carrier bearing was cut off with the grinder was well. Well techically I put a deep slit almost all the way through and was able to start spinnign it around and it finally came off.

Got all the new u joints on and I got a shop to press the new carrier bearing on. Everyting was nice a loose.

FInally got the water tank in the truck again tonight and filled it up.. Like clock work at 90km/hr I got the same noises/vibration. It's fine when your pushing on the pedal, once you take your foot off you get a vibration and a light thumping sound. My wife described it like it was when you go off the road a bit and you hit those rumble strips. Not as strong of a sound or vibration, but similar.

I paid closer attenion and I am certain the sound is almost right under my feet. I can feel it slighty under my feet as well in the floor.

I did not do the front unjoints. I honestly just didn't have it in me after the battle with the back ones. I bought the parts when I bought the back ones and told myself when I have a free weekned I'll do the fronts.

I'm thinking the front ujoints.... I got under the truck and there is the tiniest bit of play in one, but it's almost ingisnificant. But I guess they could be stiff like the back ones.

Man alive was I ever pissed when I saw how dodge has that front prop shaft installed.. It has torx bits on the front and some odd inverted torx on the back.. WTF.. why not reg hex head bolts? I'm sure the fronts will be like that rear and everything nice and seized up tight..

 

[maybedodge]

Truck still making this noise.. I haven't used the truck much so I haven't had to deal with it. But I need ot figure it out.

Ideas?

 

[GTyankee]

Did you drive it around after your Repair, without the water tank ?

Is the Ram a 4 wheel drive ?
have you ever attempted to lube the U joint on the front drive shaft, if it has a front drive shaft
do you ever use 4 wheel drive ?
do you use 4 wheel drive on pavement ?

 

[Buck416]

Never thought of torque converter bolts. I'll check them along with rear end fluid.

I may just pull the drive shafts off to inspect the u-joints as well. In the duramax, this sound was always be u joints. I'm guesing when I pull it off that carrier bearing and a u joint will be toast. I don't think the u joints or carrier has ever been done on the truck.

I don;t think flex plate since the noise is only at high speeds and during very specifc times.

Lol, I don;t know how this noise could be normal like yours is.

Shifting through gears may eliminate some possible issues , tight UJ's may well be frozen/seized UJ's especially if truck sat for some time before you bought it. Ide check those first being the lessor cost. Ive seen flywheel/converter bolts not torqued properly shear or come loose also but creates a hell of a vibration typically present through all gear ranges.

 

[maybedodge]

Getting pretty frustrated...

I replaced
-all u joints on rear shart.
-replaced front prop shaft with new
-replaced all brakes and rotors
-trasfer case fluid changed.

Some of that stuff just had to get done but also chance it was causing the noise.

Still got a noise and it was getting worse. It was getting a growl even without weight in the truck. PRetty sure it was rear end, so I took it to a good shop..

Shop immeadiately said it needs the rear diff rebuilt. I figured as much. They did the crown/pion/bear in the rear diff..

Tonight I hauled my water tank and the noise is still there. It's not as bad, but like before.. Around 90-100km if you let off the gas you get a grinding/growl.. and touch the pedal and it goes away.. I had a guy with my hauling water and he was able to move around the truck to pin point the noise and he is certain its in the rear end..

I'll call the shop tomorrow and see what they say..


I think it HAS to be the rear wheel bearings... What else would be silent until you put 2000lbs in the back?

 

[maybedodge]

Did you drive it around after your Repair, without the water tank ?

Is the Ram a 4 wheel drive ?
have you ever attempted to lube the U joint on the front drive shaft, if it has a front drive shaft
do you ever use 4 wheel drive ?
do you use 4 wheel drive on pavement ?

I have drvien it without the tank and there is no noise.

yes 4wd..
New u joints and new front prop shaft.
I use 4wd all the time.. no noise in 4wd..

 

[GTyankee]

I don't own a 4 X 4, but i was under the impression that if you used the front differential engaged on dry pavement
That it could tear the tires up & might do other damage