Does this resonating sound come and go depending on throttle in put? At light to heavy throttle it goes away, at constant even throttle the resonating increases, let off the throttle and it goes away again?

If it does it's the EBPV.

 

I have read other posts like this and it was either U joints, carrier bearing or an out of balance drive shaft.

 

Secondranch... my 2002 has the same "resonating sound" at about 2000-2200 rpms. Increase or decrease rpms and the "resonance" goes away. I replaced carrier bearing and a bad right front hub and the sound remains - minus a few other sounds. A good diesel mechanic rode with me and we concluded that it is an exhaust resonance. Can you replicate the sound at that rpm in lower gears? That is a pretty good clue. I had almost the same "resonance" at the same rpms in my '97 powerstroke and came to accept/ignore it for 185k miles.

 

I've got a very similar resonance between 65-70 MPH or around the 2000 RPM area. I also say it is exhaust resonance. It varies w/ RPM but not drivetrain related. If coasting w/ TC locked in OD it is there. Unlock TC and let RPMs fall and it is gone. Wonder if wrapping the Down Pipe would help??

 

I've noticed the same problem, well not problem but occurence. happens to me between 65 and 70 the worst. i can make it do the same thing doing 50 in 4th gear, i think it has something to do with the timing of the exhaust pulses around 2000 rpm. got more noticable when i removed my muffler, then louder again with an open element intake.

one other thing that i have noticed, when coasting or engine breaking between 1900 and 1100 when the injectors start firing again, i can hear each cylinder coming up on the compression stroke. never noticed it before, i think it has something to do with the cold, hasn't gotten above 35*F for the last 2 weeks. kind of sucks since i can drive on the highway for an hour straight and within 5 minutes of street driving my truck is back into the warm up cycle (EBPV)

 

I have what seems to be a similar problem with my '99 F250 7.3L 4x4 automatic.
At 68 mph I get a resonance or vibration and it gets slightly worse as the speed increases.
It did not go away after I replaced the tires and it does not change after rotating the tires.
I had the rear driveshaft rebuilt with all new u-joints and rebalanced and it did not go away.

The truck now has 101,000 miles on it and the problem was there when I got the truck with 38,000 miles on it from my Dad (who had purchased it new).

The front hubs are free-wheeling hubs, for what it is worth. So, I would not expect the front driveshaft to be rotating at all, unless there is some rotation coming out of the transfer case.

Why might this be the cause? When I had the rear driveshaft off I test drove the truck with the transfer case engaged and there was a fair amount of vibration on a smooth highway even at only about 40 mph.

So, could the front driveshaft be the cause of the vibration?
Note that I have just never gotten around to doing the obvious and temporarily removing the front driveshaft. It just seems that like clockwork, the vibration comes on at 68 mph. It is similar to driving on a highway with very rough asphalt.

 

If you pull the front shaft and with the hubs locked and the T-case locked in and the vibration is not there, my money is on the Double Cardan joint in the front shaft (assuming it has one).

I just had to have the front shaft rebuilt for the second time but 10 years and 400K so not too bad.

Take it to a drive line pro for rebuild.There is a stub in there for the centering ball that wears and if it's sloppy, it can be cut off and a new one welded in so complete shaft replacement is not necessary. My guess is with only 100K, yours will probably be fine with some new joints and centering ball but have it checked. If you just throw on it and it's sloppy, you'll be doing it again before long.

Post back what the fix was when you find it!

 

Yup, originally from MN and the truck is from MN.

Sounds like I need to pull the front driveshaft.

Will report back with the results.

Thanks for the feedback.

 

There was a lot of discussion about this way back in 2001, it went on for a long time. I added a section of flex pipe to mine just past the down pipe connection. I'll try and post a picture here if I can. A lot of us back then did this and it helped my drone about 50% I think. I had completely forgotten about the drone thing.
Bill

 

There was a lot of discussion about this way back in 2001, it went on for a long time. I added a section of flex pipe to mine just past the down pipe connection. I'll try and post a picture here if I can. A lot of us back then did this and it helped my drone about 50% I think. I had completely forgotten about the drone thing.
Bill
View attachment 106449

Bill,
Look at how clean and new the underside of your 2002 was.
If only trucks and dogs did not get old.

 

I don't think what I am hearing is an exhaust resonance because it is not related to engine rpm. I can go down a long hill on the freeway and get the sound/vibration right on cue at about 68 mph with the engine not needing to work very hard because of the elevation drop.

Have not had a chance to pull the front drive shaft yet, hopefully tomorrow. Will report back with my findings.

 

Does it happen in 3rd and OD?
I have exhaust drone around 1700 rpm...not too bad, but noticeable.

 

Boy, I wish. When that picture was made the truck was only a few months old. That flex pipe did help though.
Bill

 

Sorry, for the long delay getting this post updated. But between the rain and work, I finally was able to get the front drive shaft removed. I have only taken one drive so far, but it seems that the vibration/sound is still there at 68 mph. Need to find another stretch of "smooth" road then check back again.