Weird vibe between 63-65 mph

[rjohnson916]

Ok I’ve got a vibe between 63-65 mph that I have told my self for the last 2 months is the road, tires, load in the bed etc… that I’m finally deciding to post about, because it’s annoying now and becoming more frequent. For starters, I’m driving an ’05 2500 4WD Quad, Short Box, 3:73, 48re, 285/70/17 rubber, Edge/Attitude the rest stock. Since late August I’ve been using my truck for my business. My truck went from garage queen for a year, to now dedicated workhorse every day. I finally feel like I’m getting my money out of my Diesel upgrade. Oddly enough my truck has been as reliable as a Swiss® watch for almost two years now. Recently ever since I started using it for business, I have usually 400-600 lbs in the pickup box worth of gear, tools etc and small 2K lb trailer w/ 3K lbs worth of stuff inside. I now have a harmonic, vibration that occurs intermittently only between 63-65 mph? Smooth as glass above or below these speeds, but within that range it feels like your driving over cobble-stone (slight-exaggeration) at first I thought it was doing it only pulling a grade, but I’ve had the vibe sneak up on me going down hill. Everything appears great and in good shape, I don’t know what I should be looking for. Also since this is my only vehicle right now, if it’s in the shop I’m out of work. I need to try to figure it out on my own as much as possible, should I need to put’er in the shop I want to avoid as much diag time or down time as possible. Anyone got any ideas or what to look at?



Thanks in advance



-Ryan

 

[F-15I Ra'am]

I would say it's probably bad u-joints.

 

[rjohnson916]

I would say it's probably bad u-joints.

Thanks for the heads up, what are and where are these U-Joints located on the truck? I've never really tackled taking a truck apart so to speak.



-Ryan

 

[tazzen]

Ryan,



i just had one at 48-53 mph. nothing above or below. my drivers side front wheel bearing endded up being my vibration.



ed

 

[Troll]

U-joints connect the drive shaft to the axle. They are the + shaped pieces between the driveshaft and the pinion yolk. You have at least 2 per drive shaft, as well as 2 for the front wheels( 4x4 only). hopefully someone can snap a photo for you( my camera is broke).



If you download the manual from hemitruckclub.com I think it will show you a picture.

 

[Big Mike]

I would start with having all four tires balanced, at those speeds, sounds like a balance issue to me. Also, rotate your tires, see if there is any change.



Mike

 

[captainmike]

Driveline angle

Ryan,

Your problem may be the driveline angle. The dealers and DM are aware of this problem. I have an '06 Megacab with a split driveshaft (3 U-joints) and the support for the center U-joint had to be changed. A shorter one was installed, under warranty, changing the angle of the driveshaft to the rear end. The problem went away. My problem was a vibration 56-64 mph when my trailer, a 10,000 lb fiver, was under tow. Since you carry a load on the truck all the time, thereby lowering the back end, this may be your problem. Try unloading the truck and then driving it to check out the vibration.



Good luck, Mike (Homestead, FL)