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%.

 

[cags]

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.

Hi Scott,
I will get my 35mm impact socket and start to yank them out. Look like it pays to buy new shaft instead of trying to change ujoint inside of boot. Thanks a million. Will keep you tuned. Joe

 

[Scottydoggs]

rebuilding is doable. but a major pita im sure. watched vids for my regal, and was like ill just buy reman 1/2 shafts lol


another tip, do not drive the truck with no shafts in place, the wheel hub/bearing will explode and toss the front wheel off the truck.....seems like a good test but it can bad pretty fast.

 

[cags]

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

Hey Scott,
Yes I have a awd Yukon. Thanks again

Joe

 

[alaska_guy]

When you lift off the throttle does the issue go away? Sounds like torque converter shudder to me. Typically if it's driveline related you feel it around 35mph on most vehicles. Next time it happens let off the accelerator and tap the brakes and then try accelerate again.

I briefly read the posts, but my money is in bad torque converter. Google torque converter shudder.

 

[cags]

When you lift off the throttle does the issue go away? Sounds like torque converter shudder to me. Typically if it's driveline related you feel it around 35mph on most vehicles. Next time it happens let off the accelerator and tap the brakes and then try accelerate again.

I briefly read the posts, but my money is in bad torque converter. Google torque converter shudder.

hey kendall,did check my axle shafts all okay reinstalled and continuing tshooting. I did notice a drop in rpm when approaching 58mph and slight fluctuation on tach needle. Looks as if lockup in 4th is teeter tottering. Am thinking tcc solenoid or possible clutch. Will go and check filter after draining and removing pan. If filter is clean with no metal will replenish fluid and filter and go from there.
Thanks for the info.

Joe

 

[alaska_guy]

K, just FYI... My truck did the torque converter shudder for a good 4 years before my torque converter finally let go. Truck is in the shop getting the transmission overhauled. Truck has 255k on the original transmission and torque converter. I knew it was gonna give up the ghost eventually and I wanted to rebuild the transmission anyhow with that many miles vs just fixing torque converter.

My fluid always looked red and clear, no metal ever and fluid level was always fine. Took about 40k miles after i noticed it before it finally completely failed.

 

[kiboater]

You might want to explore the TCC (torque converter clutch) issue. Generally if something is bent or loose the vibration does not go away. Balance issues will peak at a given rpm. The more likely possibility is an issue when the torque converter locks up at 40-50 mph to increase mileage. It can cause a shutter. There are various ways to diagnose this including shifting to a lower gear. Here is a link to a GM bulletin for the newer trucks and describes the problem. There is a later bulletin that calls for the fluid to be changed and replaced with a newer designed fluid.
https://static.nhtsa.gov/odi/tsbs/2017/MC-10139218-9999.pdf

 

[Rocket Man]

Hey Scott,
Yes I have a awd Yukon. Thanks again

Joe

Definately don’t drive without the front driveshaft even for a tiny bit then or you’ll destroy the transfer case. Just a heads up.