Spring Clamps Reduce Rear Vibration

ic3man5 · March 30, 2016

Pinion side shot posted. Looking at it, there is little pointing up which is where it needs to be.

Any chance you can attach your camera to the rear axle facing forward? Its hard to tell in the video but it almost looks like there isn't any vibration going on in the drive-line and its all in the body. I'm curious if the same shake will happen in the video if you have it on the axle. I wonder if clamping the springs making them stiffer is helping restrain the vibration;

edit: I've had a suspicion for a while a lot of the roughness and vibration is happening from the front and the stiff frame is transferring it to the rear of the truck since it has the least amount of mass.

Edited March 30, 2016 by ic3man5

KLRV6 · March 30, 2016

Is this your truck KLRV6?

Are you saying the pinion angle is correct and yet you still have the vibe? Just trying to decipher this. Thanks!

Yes it is my truck. The pinion working angle is out of spec. 3.09 degrees difference and it needs to be .25 - 1 degrees. So, a 2 degree shim would make it 1.09 degrees, which is much better than where it is now. If needed and it wouldn't upset the front too much, I can adjust the rest out at the transfer case. It wouldn't take much more to get it around .75 degrees. Yes, it's good to have an angle, but this is way off and it can get enough movement from the suspension moving up and down to keep the u-joints lubricated.

KLRV6 · March 30, 2016

Any chance you can attach your camera to the rear axle facing forward? Its hard to tell in the video but it almost looks like there isn't any vibration going on in the drive-line and its all in the body. I'm curious if the same shake will happen in the video if you have it on the axle. I wonder if clamping the springs making them stiffer is helping restrain the vibration;

edit: I've had a suspicion for a while a lot of the roughness and vibration is happening from the front and the stiff frame is transferring it to the rear of the truck since it has the least amount of mass.

I already have one of the rear. I'll post it tomorrow. There is so much going on with the suspension.

hotrodz37 · March 30, 2016

Yes it is my truck. The pinion working angle is out of spec. 3.09 degrees difference and it needs to be .25 - 1 degrees. So, a 2 degree shim would make it 1.09 degrees, which is much better than where it is now. If needed and it wouldn't upset the front too much, I can adjust the rest out at the transfer case. It wouldn't take much more to get it around .75 degrees. Yes, it's good to have an angle, but this is way off and it can get enough movement from the suspension moving up and down to keep the u-joints lubricated.

Awesome, thanks for your insight on the matter! Hopefully the shims will help for you! When do you plan on having them installed?

ic3man5 · March 30, 2016

I already have one of the rear. I'll post it tomorrow. There is so much going on with the suspension.

Awesome, looking forward to seeing it.

KLRV6 · March 30, 2016

Awesome, thanks for your insight on the matter! Hopefully the shims will help for you! When do you plan on having them installed?

The truck is on week three at the dealer. If they don't take care of it. I will once I get it back. They informed me the other day that they have had to keep one of their customers trucks for three months and still couldn't fix the vibe.

LongrangeLauber · March 30, 2016

The truck is on week three at the dealer. If they don't take care of it. I will once I get it back. They informed me the other day that they have had to keep one of their customers trucks for three months and still couldn't fix the vibe.

I can guarantee that truck sat in the parking lot for 10 of 12 weeks and just said they were working on it the whole time, ain't no way GM would authorize that much reimbursement for warranty work

KLRV6 · March 30, 2016

I can guarantee that truck sat in the parking lot for 10 of 12 weeks and just said they were working on it the whole time, ain't no way GM would authorize that much reimbursement for warranty work

They had one that 80 hours was "invested" in and GM paid for 10. I call them every day or two and request a status update. I understand things take time. If they let it sit, that when my tolerance runs out. My truck was there two and a half weeks before they even looked into the complaint I had about the transmission whine.

14silverado4.3 · March 31, 2016

So I clamped 5 inches behind the axle. It stiffened it up and bumps feel horrible but it seems to have taken some of the "extra vibes / noise" out of the drive. With clamped behind the axle, what does that do with pinion angle?

I am thinking there is lots of resonance coming from the suspension

LongrangeLauber · March 31, 2016

So I clamped 5 inches behind the axle. It stiffened it up and bumps feel horrible but it seems to have taken some of the "extra vibes / noise" out of the drive. With clamped behind the axle, what does that do with pinion angle?

I am thinking there is lots of resonance coming from the suspension

It will point the pinion down, so more of a negative angle

KLRV6 · April 2, 2016

Awesome, looking forward to seeing it.

Sorry it took so long to get posted. 2015 Silverado rear view at highway speeds

. It was a rough week at work. I did get my truck back and the vibration is gone at highway speeds. I am cautiously optimistic about the repairs being permanent. The dealer performed the transfer case update, replaced ring/pinion and bearings, replaced two rear shocks - one had completely failed and had oil leaking out of the top. This is a non-Z82 truck.

I will get another video at the same view with the repairs made.

KLRV6 · April 2, 2016

Any chance you can attach your camera to the rear axle facing forward? Its hard to tell in the video but it almost looks like there isn't any vibration going on in the drive-line and its all in the body. I'm curious if the same shake will happen in the video if you have it on the axle. I wonder if clamping the springs making them stiffer is helping restrain the vibration;

edit: I've had a suspicion for a while a lot of the roughness and vibration is happening from the front and the stiff frame is transferring it to the rear of the truck since it has the least amount of mass.

I will get one of the camera attached to the axle.

650h1 · April 2, 2016

So what is the verdict on tightening the U-bolts/adding another clamp to the leafs? IMO, the last thing anyone on this forum wants to do is start screwing with the pinion angles and the driveshaft; you'll never get it shimmed just right, and you'll make yourself crazy trying to do it. The pinion angles are also not going to affect high-speed vibration as much as they will affect the low speed shudders. To be honest, I think the fix for these trucks is going to be a custom made one-piece driveshaft, but I have a lease, and I'm not putting that much effort into it.

KLRV6 · April 2, 2016

So what is the verdict on tightening the U-bolts/adding another clamp to the leafs? IMO, the last thing anyone on this forum wants to do is start screwing with the pinion angles and the driveshaft; you'll never get it shimmed just right, and you'll make yourself crazy trying to do it. The pinion angles are also not going to affect high-speed vibration as much as they will affect the low speed shudders. To be honest, I think the fix for these trucks is going to be a custom made one-piece driveshaft, but I have a lease, and I'm not putting that much effort into it

I am waiting to see if the current repairs have resolved the issue. If vibration comes back, I may take the driveshaft out and have it checked by a specialist.

650h1 · April 2, 2016

I am waiting to see if the current repairs have resolved the issue. If vibration comes back, I may take the driveshaft out and have it checked by a specialist.

what exactly did you do?