Shutter at approximately 58 mph

[cags]

2005 Yukon. At approximately 58 mph there is a shudder on acceleration . Initially I suspected u-joints. Removed both front and rear driveshafts ,replaced all joint's, found one questionable but I realized it was not the fix and I was correct. Reinstalled both driveshafts and condition still exists. I than inspected front end for any loose structure, control arms, tie rod ends, etc. There is no steering wheel shimmy at all so I'm ruling that area [front end] out. As a point of interest, when I let off the gas pedal, shudder disappears. I'm thinking engine mounts or front differential area, transfer case.????
Any input from anyone out there experienced similar situation. I'm all ears.

Thanks

Cags

 

[Scottydoggs]

id be looking at a front axle shafts, they basically have u joints inside the boots. act the same way as a bad U joint, so in the end, you just might be right still, but went after the wrong u joints.

 

[Erickk120]

Is this new or has it been going for a while? Does it go away after 58?

 

[cags]

id be looking at a front axle shafts, they basically have u joints inside the boots. act the same way as a bad U joint, so in the end, you just might be right still, but went after the wrong u joints.

Thanks, Scottydoggs, I will follow-up and check front axle shafts.

Is this new or has it been going for a while? Does it go away after 58?

This is a new condition. And yes it does go away after 58-60mph or if I let up on the gas pedal.
Thanks again for the input.

 

[cags]

Is this new or has it been going for a while? Does it go away after 58?

Yes, this is a new condition and shudder does go away after 58mph or if I let up on the gas pedal.
Thanks,
cags

 

[Erickk120]

Yes, this is a new condition and shudder does go away after 58mph or if I let up on the gas pedal.
Thanks,
cags

The thing with vibrations/shudders is the they are obviously caused by something that is rotating. Could be as easy as a tire out of balance, lost weight,bent rim to a unbalanced driveshaft could either be back or front or even cv joints. It could even be caused by a bad converter, or bad bearings in the diff, to transfer case you never know, hard to pin point without further diagnosis. I would start with tire balance, if that doesn't change anything I would move to the drive shafts. Have you removed them before you noticed this "shudder?" I would take the front one out and go test the rear, if nothing changed then you know its not the front ds. The rear will be tricky, since it will wanna leak if you do this, so I wouldn't recommend doing this for the rear. If you have taken it apart before though make sure you put it back the same way it came out.Otherwise it might vibrate at higher speeds, I've noticed these trucks have a weight in the diff yoke so if misaligned with the ds they vibrate when you hit highway speeds, that is what was causing my vibration last time I had one, the they have to be around 180 degrees from each other. See if you go over 60 mph and decel do you still notice it when it decels at 58, or are you sure its only on accel?

 

[Big Mama]

Agreed look for a missing tire weight on the inside and out on all 4.

 

[cags]

The thing with vibrations/shudders is the they are obviously caused by something that is rotating. Could be as easy as a tire out of balance, lost weight,bent rim to a unbalanced driveshaft could either be back or front or even cv joints. It could even be caused by a bad converter, or bad bearings in the diff, to transfer case you never know, hard to pin point without further diagnosis. I would start with tire balance, if that doesn't change anything I would move to the drive shafts. Have you removed them before you noticed this "shudder?" I would take the front one out and go test the rear, if nothing changed then you know its not the front ds. The rear will be tricky, since it will wanna leak if you do this, so I wouldn't recommend doing this for the rear. If you have taken it apart before though make sure you put it back the same way it came out.Otherwise it might vibrate at higher speeds, I've noticed these trucks have a weight in the diff yoke so if misaligned with the ds they vibrate when you hit highway speeds, that is what was causing my vibration last time I had one, the they have to be around 180 degrees from each other. See if you go over 60 mph and decel do you still notice it when it decels at 58, or are you sure its only on accel?

Hi Eric, Shudder occurs on accel only, when I let off on the gas pedal, shudder disappears. Now, noticed happens at 58mph or when approaching 45-50 mpg but when letting off the pedal shudder disappears. Thanks cag

 

[Scottydoggs]

its got to be a axle shaft gone bad, only reason for to be there only when in the gas, when you coast theres no load on it so the vibration goes away. just like a U joint in a drive shaft. if it was a tire it would vibrate no matter in the gas or not.

i just started to get a vibration at 70 mph, i could tell it was the front tires right away, rotated em and no more vibration. but mine didnt go away at 70 on or off the gas, how i just knew it had to be the wheels.

 

[Scottydoggs]

you got a awd truck? that would confirm my thoughts a 100%.