Jump to content

Recommended Posts

Posted (edited)

 

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 by ic3man5
Posted

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.

Posted

 

 

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.

Posted

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?

Posted

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.

Posted

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.

Posted

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
Posted

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.

Posted

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

Posted

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
Posted

 

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.

Posted

 

 

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.

Posted

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.

  • Like 1
Posted

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.

  • Like 1
Posted

 

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?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Latest Articles

  • Posts

    • Hey guys, sorry for the confusison about this. This wasn't my experainnce, it was copied and pasted fom the net. 
    • The problem with failure rates or increase failures are there’s people who don’t have a problem. What are you doing wrong they say. We had 4 5.7 GM diesel’s in the family when they came out. One was flawless. My uncle who happened to be the most abusive. Early rotary engines were known to use oil. I abused my first car so bad in six months I replaced the clutch, transmission and rear end. It didn’t use oil. My brother in law has a 2013 Tahoe and an older Yukon. The Yukon has 280K miles. The Tahoe around 175K. He runs them to about 300K. If his lifters fail before that time he would consider it a failure. My Hondas, I know people hate it when I mention them. Identical engines. One with cylinder deactivation one doesn’t have it. One shudders when the eco light goes on or off. Cylinder deactivation. But wait! According to the web. It can happen with lock up too. So now people in the know are changing the oil and transmission fluid more often. Then you read it could be a programing issue. So what do you do? There’s lots of money involved. I see three ways to deal with it. One only works if you don’t drive lots of miles. Lease, never get out of warranty. Or only buy older vehicles with a good track record. They all have bad runs. Usually when there’s a change. Even Toyota and Honda. 
    • Question @diyer2 on this line if you please. Are you saying the shudder is the system turning on and off at the frequency of the shudder? Guess I'm asking if you are saying you have seen it do this with the bi-direction scan tool in graph mode? If so have you been able to discern the 'trigger'. Something is telling to cycle rapidly.    My truck just started doing this recently. 197K on the clock. My response has been M5 anything under 55 mph. I treat it like a lugging stick shift. Gear down and let it spin a bit. Engauge M5, then tow mode and then M6 lets the trans stay in 5th but the AFM is active. Smooth like Skippy.    My thought was that as a machine ages the friction gets lower and as the system is load based, the lower friction would allow it to turn on at ever lower rpm until it reaches the lugging point. And yes I am ignorant of any minimum rpm requirement for the system. If you know that would be useful information.    As you know I run a Scan-Gauge II which allows me to watch the On/Off of the signal to the VLOM. While in the shudder mode I'm not seeing is cycle at that frequency or at all for that matter outside the triggers @newdude posted a few years back. Now is it possible that the refresh rate isn't fast enough to catch it? Maybe. It is why I asked my first question about graphing and trigging parameter.     As we have observed from members here the failure point is all over the map miles wise as you note yourself in your opening post. That by itself begs a few questions like fellows that comment on these lifters failing even after the system has been disabled. Long after. 😬   https://www.enginelabs.com/news/tech-tips-replacing-ls-active-fuel-management-lifters-with-melling/   The Gen5 lifters operate the same as the LS versions. In fact they are the same lifter.    https://www.enginelabs.com/tech-stories/sorting-out-gen-v-lt-lifter-failure-with-a-simple-valvetrain-fix/        
    • UPDATE 2: Steering wheel control backlights and control of the cluster can supposedly be achieved by adding a wire to pin 20 of the cluster and tapping it to pin 2 of the main clock spring harness. I'm going to give it a shot - will update  
    • GM Global A pickups 2019-2022 can do OTA programming for the radio.  GM VIP (GM Global B) can do OTAs for almost every module on board.  So a 2022.5 and newer pickup can do OTAs for recalls like the 2.7 fuel flow recall.  EVs get OTAs that improve one pedal driving, radio issues, HVAC issues, updated battery management software, etc.     So age of the vehicle/what GM electrical platform its on will alter what amount of updates can be pushed on OTAs.  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...