TwoBallScrewBall

"I don't back up" lolol.....

We have a new 2018 (4 months old) with 4000 miles and my wife just got the "Service Brake Assist" and a hard, pulsating pedal every time she applied the brakes this morning. Turned the truck off then started back up and everything seemed fine. Do they think the 2018's are not affected? We tow a camper with this truck all the time, I don't need to be losing power brakes with ~6000lbs of trailer hooked up and my 2 kids in the back seat. Will be calling the dealer about this later today.

Popped the new CV axle in yesterday. Back on the road.

There were big blobs like you describe on the A-Arms, and on the inside of the wheel barrel. This leak was right near the spindle, maybe that's why most of my mess ended up on the wheel and A-Arms instead of the axle like yours. Some of those blobs on my wheel had 'ran' out the outside of the wheel and onto the face toward the tire, kinda like running paint. I guess from the centrifugal force of the spinning wheel.

Nice clean front wheel on my security camera the morning I dropped the truck off..... I should have taken a photo of the wheel before I cleaned it but I didn't, but there was black grease streaking out between the spokes. Had the truck backed in since we've had it home, we always back it in, but it was pulled in nose first earlier this week from when I had installed some amber marker lights in the grille (that's another thread). So I have some evidence that suggests the puncture and grease leak might have happened at the dealer..... what the hell.....

Can't catch a damn break here. Called all around for a replacement CV boot, nowhere has it aftermarket, GM boot is $88 for the boot, bands and grease. I already have the axle out so I said screw it and dropped the $95 with tax. Turns out the large band clamp does not use the usual ears, but some GM contraption that sits in a vice and compresses the entire solid ring onto the large end of the boot. Of course nobody has it locally. Additionally, there is no way the strut spacers caused this issue, it's a puncture. picture below. Anyway, after determining that this wasn't going back together today, I hit up Rockauto and got the entire damn replacement axle for $88 with tax and shipping, which is $7 less that I got hit for on just the damn boot from GM. Taking that back, prob get hit with a restocking fee. The other local dealer I called also said that GM has been swapping out the entire axle shaft under warranty in cases of boot tears. Which is why they don't have the clamp tool on hand, they have never had to use one. The more I think about this entire experience with this service department (purchasing dealer), the more aggravated I get. They didn't bother even checking where the grease was coming from, just said the boot must have split from the lift blocks. The boot is super soft, its a 2018 with 2500 miles on it, I don't think I could split it if I tried at this point. They also fast talked me into believing that this grease leak was somehow causing the vibration. I am really kind of wondering if they poked the damn boot and then just expected that I would pay for the axle repair out of pocket since they were blaming it on the spacers. That boot is always spinning, I would expect a tear in it if I hit anyting on the road. This is a puncture. The front wheel is also covered in grease, something I am 99.9% sure that was not there when I dropped the truck off or any time before, my wife or I would have noticed. it. The whole experience just leaves a bad feeling. New axle should be here mid week, hopefully done with this after that.

Fixed. Dealer did not fix it. Picked up the truck. Dealer had me under the truck and said the vibration was coming from the front end. Showed me that the driver side CV boot has a split/leak and it's flinging grease, and said that the increased angle with the front lift spacers is causing the vibration and the split boot. Could not argue with him there. Running 3" top-mount spacers. I had read about the stress on the ball joints when running 3" spacers, but I don't off road with it. So I took the risk. Never read anything about CV issues. So I told them I'd address the cracked boot and the axle if needed and pull the spacers, paid my unexpected $80 for the diagnostic (that sucked) and went on my way. Driving home, I get to thinking about the front axles spinning on the highway, and I look down and notice I'm in 4WD AUTO. I flip it back into 2WD and sure as shit, absolutely no more vibration. No shit, wasn't supposed to be in Auto all the time, especially at full throttle at 70mph. So, basically paid $80 to be told I split a CV boot that actually has nothing to do with the vibration I brought it in for. I'm easily at fault here, I left it in auto, I lifted the front end, etc, etc. I do have a bit of a bad taste though about dropping the unexpected $80 and nobody there noticing in 50 mile of test drives that it was in 4wd auto. Again, neither did I until I started thinking about the front of the truck as opposed to the rear, but I'm not a paid tech. Moral of the story, don't stay in 4wd auto.

Got a call from my service writer yesterday afternoon. They had called me on Wednesday morning to let me know that they they thought they might be feeling something, but were not sure because it had started snowing and they couldn't safely hammer the throttle at high speed. I told them to go ahead and keep the truck for a few more days since the weather forecast was good. He confirmed yesterday (Thursday) that they have 45 miles on the truck now and they do feel the vibration at around 70mph, which is a good thing. At least we're past the "can not replicate issue" stage now. He was consulting with his folks within the dealership because they felt that it might have something to do with the lift blocks I have in the rear end. I politely explained that those were the factory lift blocks that come in all those trucks, and he sounded surprised by that which mildly concerned me. I did let them know that I had 3" blocks installed for some time, but removed them and the truck's rear suspension is set up now as it was from the factory. Also let him know that I do have the 3" strut spacers in the front, we both agreed that should not be any concern. If that becomes an issue, I personally don't have a problem temporarily removing them, except for the $80 I'd have to drop on another alignment if I take them out. This was late yesterday afternoon. Waiting on additional updates today.

Dropped it at the dealer last night. Will update on whatever they find.

So current status, rear suspension returned to 100% factory. Front strut spacer blocks still in place. Truck is dead level right now, but I need to tow with it so I do need to bump the back up another inch or two. Even with the rear suspension / pinion angle returned to factory, the vibration is still there. If I floor it from a stop, 1st and 2nd are dead smooth all the way through. When I get to third, pulling through 65mph, the vibration starts abruptly and is there under power, more power = more vibration. If I let off the gas but maintain the same speed, the vibration goes away. Even if I give it about 1/2 throttle so it's accelerating in 4th gear at those speeds in stead of 3rd, vibration is still there. Unless anyone has any other ideas, I suppose I'll let the dealer look at it now that they can't say it's the lift blocks.

2016 lease was up and both the wife and I wanted to upgrade from a double cab to a crew. Good news is we bought this one!! /s

Put the stock blocks back in and removed the leaf clamps, so it's back to 100% factory. Still the same significant vibration anywhere above 65mph with power applied. No change from the 3" blocks to the factory blocks. Wonderful....... 2500 miles and I'm in the mystery vibration club. Should have kept my 2016.....

Clamped the front of the overload springs today. I like the ride better, a bit stiffer but nothing crazy. But no change in the vibration with the clamps, I still have a strong vibration, only under high power and only above 65mph or so. Truck is smooth at any speed at cruise, and smooth under accel until about 65mph, at which time I get a strong vibration, feels like from the rear, until I lift off the gas. Vibration is persistent from 65-85, did not go any faster than that. Next step is to put the stock blocks back in the rear and remove the clamps, and see if I still have the vibration. If so, I might let the dealer take a look at it. If not, then I need to decide where to go from here since I have a 3" level in the front, so I can't leave the rear stock, as it would sit too low. Can we use lift shackles on a 2018 instead of blocks? Wondering if some of the problem is the additional distance between the spring and the axle with the larger blocks, allowing vibration to amplify or resonate / providing more axle leverage on the spring.

Where is the adventure in that???? I'm not ready to be boring just yet. Although I HAVE been told I have old man lights on my truck.... EDIT - excuse me - the wife's truck.

I swapped in the angled blocks I had. 2 Degree I think. Installed so the pinion points more toward the truck, not the ground. Vibration is still there at higher speeds under acceleration, 65-80mph. Might not as bad as with the flat blocks but I'm not sure. I am going to clamp the front of the leafs, I read that helps sometimes. Makes sense, as clamping just the front of the leaf will make it stiffer, as well as give just a bit more upward pinion angle.