RPM specific vibration

[Wil_H]

I searched the list and couldn't find a post that matched my problem.

At 1450-1550 rpm and 1950-2050 rpm there is a vibration that I can fee through the steering wheel and gas pedal. It is sort of a thumping feel. It does seem to be faster at 2000 rpm than at the lower rpm range. IT IS independent of speed. With the OD off I get the vibration at the same rpms. It is more apparent with the engine loaded as in going up a hill.

Any thoughts?

Thanks in advance

Wil

 

[DPKetchum]

There are vibration issues with some of them. My new 03DRW H. O. six speed with 4. 10 gears a roar starts at 60 and 2000 rpm and at 68 mph a quick sharpe vibration and at 70 plus goes away. Real unhappy about that issue. Dealer is aware. Was told D. C. was aware. Call D. C. etc.

 

[Badunit]

I have the same thing but only in the 1950-2050 (or so) rpm range. It isn't a vibration like some people are experiencing, it is definitely a thumping. I don't know what it is either but I'm not concerned that it's anything mechanical. Maybe it's exhaust resonance or maybe it's related to fuel injection timing.

 

[LightmanE300]

maybe some part of the driveline is out of balance?

 

[DPKetchum]

For such nice truck its defently a issue.

 

[Wil_H]

It looks like PCline has found the answer to the vibration issue.

He has an excellent write-up at:

PCline's post



A very brief look under my truck and it is clear that there was very little attention paid to drive shaft geometry.

Now all I have to do is find someone with all of the right tools and know-how

 

[Badunit]

I think there are two separate things going on here. Some people are experiencing driveline vibrations that happen at certain vehicle speeds. Others are experiencing a "thumping" that happens at specific engine rpms. I think Wil_H has the second one (and so do I).

 

[hbowers]

my truck has been making the noise at 2000 rpm for about

3k miles. I have 15k on it now. I ruled out the drive train

because it does it sitting in my shop at 2000 rpm.

I took my mechanics stethoscope to my cousins house

today and had him listen to every thing on the engine that

has a bearing in it while I held the rpm's at 2000( where the

noise was present) and he said everything sounded smooth.

then he listened to the injector lines, and # 1 line made

a heck of a racket compared to the others. so maybe we

stumbled on to something. hmmmm bad injector?

don't know but will have a dealer check it out.

I don't know if we are all experiencing the same noise or not.

 

[Shooter]

Mine has the THUMP and vibration.



The thumping is drive line as if I put the clutch in it disappears and as soon as I let it back out it starts immediatly. could be front driveline or rear drive line, I don't know which yet.

Does any one with a 2wheel drive have the thump???



The vibration starts a 2k rpm driving or sitting still. There is something either inside the front of the door or in the extreme left dash that buzzes like a big fly at and only at exactly 2k rpms.