I have a 2001 CC long box psd and am very happy with it but am having a few problems. I f you have a car trailer on the back and you accelerate very hard, it shudders really bad in the middle of 1st gear before it shifts. It shakes the dash and the steering wheel. If I dont have a car trailer on the back it dosen't do it. The dealer said it has something to with axle wrap but I don't agree with them so I'm going to take it to a different dealer. The other problem I'm having is that if you go 75M.P.H. in overdrive on the freeway the thing makes a whirring ,sort of a ocillating noise coming from the engine bay. It comes on at about 70 and goes until about 80. The faster you drive the faster it ocilates. It has been there as long as I've had the truck .I bought it new. The dealer has no idea and has blown me off when I ask about it. The truck is all stock.

I would greatly appreciate any help.
THANK YOU Craig

 

I must admit, and I am no expert, BUT these types of NHV problems drive me crazy. As for your shudder, in my experience, I would rule out the trans(torque converter)...if I am wrong...somebody please chime in. I believe your two problems are interelated. Have you checked your driveline for lose or worn parts...ie carrier bearing, u-joints, spring u-bolts, springs(broken/cracked)? Second, I would look at trans and engine mounts. You may have to look closely or jack the part up just under the mount to see if it seperates. Axle wrap can cause some vibration since when the axle twists upward on acceleration, it changes toe angle of the drive line...thus exaggerating any resonance present with moving parts...there is always some sort of resonance....we just can't feel most of them. I would check these parts first...also check your slip joint, wither at the trans output shaft, or at the carrier bearing...depending on which truck you have. A dry slip joint usually causes a "clunk" on acceleration, but weird things happen with rotating parts, so a vibration may occur as well. One more thing, make sure your drive shaft is in proper phase...by this I mean the drive shafts are usually balanced as an assembly and there are marks on the yoke....they may be a number, a notch, or some other identifying mark. These marks must be in line with each other in order for the drive line assembly to be in balance. Keep us posted as to what you find out

 

Craig, the shuddering sounds exactly like axle wrap, especially since you say it only happens midway through 1st gear with a heavy load. That's where the maximum torque is applied to the driveline, and if it's going to happen, that's when it will be at it's worst. The second half of the driveline is fairly short and won't tolerate a lot of misalignment. I could be wrong though. It's hard to actually tell how much axle wrap you have (the number of degrees it turns), but if you're really bored one day you can do what I did and duct tape your video camera under your truck and take it for a short drive. Just make sure your girlfriend (wife) doesn't know what you're doing with the camera...

As for the engine noise, the oscillation might point to a belt driven accessory, as the engine hits a certain speed you'll have harmonics from two pulleys of different size. Maybe a loose fan blade, bad A/C clutch, slipping/vibrating belt? There's a TSB out on slipping belts, look on this forum for the post "Rapid Chirp Noise when Spooling Up."

Anyway good luck I hope you find out what it is.