ajs67donzi

My guy ruled out wheel bearings...goes to show what I know! He "re-learned" the transfer case and front axle lock up, and we're both hoping that solves the issue. I've only driven it twice since, without no noise recurring, so my fingers are crossed.

One year old transmission rebuild, stem to stern. I've had it back to that shop, who have a good reputation, and they deemed it fine. To me, the rumbling does not appear to be shift related. It's frustrating because the noise only exhibits itself occasionally, and of course never with the mechanic in the truck! My guy is looking at the wheel bearings today, so maybe I will know more after that. Thanks again!

Coming from the front right, I occasionally hear what feels and sounds like I'm going over a rumble strip along the edge or middle of a two-lane. It's at various speeds, and seems more likely to happen on slight curves. I'm thinking wheel bearing, but would welcome any other ideas. Thanks in advance for your thoughts!

My Florida guy is trying everything before acknowledging it's a bad torque converter. Related to the suggestion above, he has me adding a Motorcraft product called "Additive Friction Modifier". I'm hopeful, but not overly optimistic!

I remain frustrated by this problem. Definitely still shuddering, despite attempted mitigation. Assumption is a defective torque converter, despite it being new and of a higher quality (CV-GM10405-S1). My bad luck, apparently, compounded by the transmission shop being in Florida and the truck being in Virginia. It's covered by an ATRA Warranty program, but my Florida guy has hesitations about taking it elsewhere. He worries the shop might promise the upgraded torque converter, but install a less expensive model.

...usually from 2nd to 3rd gear, but sometimes from 3rd to 4th. It's only noticeable when light on the pedal, and it's not a violent shudder. When I'm firm on the gas it shifts like butter. (2015 GMC Sierra 1500, 5.3L, Denali edition, Engine Code T, Truck # 6L90, 133k miles on it.) Here's the puzzling part...5,000 miles ago I had the entire transmission replaced by a shop in Sebastian, Florida! With the truck currently in Virginia, they suggest a few things to narrow it down. Shudder Fix because it is easy, and Chevron Techron in case it's a misfiring engine. The local auto store scanned for a code and found none. I also unplugged the AFM disabler. I'm hoping this slight shudder is normal at a certain RPM while accelerating carefully, and that I am unnecessarily worried. But, I wanted to see if anyone had any other thoughts. Thanks in advance for any suggestions or opinions!

More research, and I've found the solution. Find the "Clear Private Data" option under settings...and voila!!!

UPDATE: Adding to the puzzle, I am able to store FM stations, just not Sirius stations.

Had my transmission rebuilt, and since then have had trouble storing radio presets. Interestingly, I was able to do two successfully...then nothing. Pressing and holding shows a light for a second, but does not beep and store the station, no matter how long I hold. Restoring to factory default has not solved the problem, and a search has not revealed any solutions. All help or suggestions are appreciated...THANKS!

Lots of metal shavings from the torque converter were found in the transmission pan. Diagnosis...grave. Treatment plan...transmission rebuild. Cost...more than I'd like, but way less than a dealership.

Update: Fluid level is fine. Dipstick was read while engine was off, instead of while running. Duh. A consult with a transmission shop says he sees several of these per month, with metal shavings accumulating and interfering with the torque converter, clutch, and pump. He opines that it is a design defect, and my initial research sees several class action lawsuits...but, as usual, not enough for GM to concede culpability. Next he will be test-driving it, checking the filter, and doing a scan. Hopefully it won't be a worst-case scenario!

Here is how the dipstick reads hot...it's almost up to the bend in the stick. Captain Obvious says that is too much fluid.

6-speed. Level checked at both cold and hot temps, and it is still high. Doing some reading I see that one of the symptoms of overfilling is "erratic" shifting, which is what I believe I have. It doesn't look like any major damage is done, so that is (hopefully!) good news. I'll be taking it in tomorrow to siphon out some more fluid...and will be keeping my fingers crossed.

At medium speed, maybe between 30 and 40 mph, my transmission seems to bump back and forth, seemingly trying to decide what gear to be in. It is definitely a new problem and, although slight, it is noticeable to me. A month prior to this I had the fluid sucked out and replaced with new, at an oil change place, and at the same time I had them add half a quart of LubeGuard Red. It is the second flush I've had done, one at 90k when bought the truck, and then this one at about 125k. After driving to Florida I checked the level, and it read high, so I had a shop suck some out. It is still reading slightly high, but the guy said it was all he could reach, and it should be fine. It was a week or so after this that the problem started. Could an overfilled fluid amount cause this issue? Am I in for a significant transmission repair crisis? Oh...woe is me!

I do not consider myself a "criminal", but freely admit to occasionally exceeding speed limits. I believe most people here, if not all, would fall into a similar category. If you crash, and the black box shows you were going over the speed limit, and the insurance company refuses to pay on the claim, is that an acceptable evolution of this technology?

Informative link, thanks for sending it. After reading the excerpt below, though, I wonder what the law is in the states that have not yet enacted legislation governing EDR's. In December 2015, the federal Driver Privacy Act of 2015 was enacted. It places limitations on data retrieval from EDRs and provides that information collected belongs to the owner or lessee of the vehicle.

A recent event has drawn attention to the EDR, aka the "black box". 1) Can insurance companies use it to deny claims? 2) Can law enforcement use it to prosecute? 3) Can an owner remove it, without penalty? 4) Do rules vary from state to state?

UPDATE: To say that the GTR Ultra LED bulbs are a significant improvement would be the understatement of the century! Brightness is about 100 times better than the factory halogens, and nighttime driving is now both comfortable and safe.

The shop is Extreme Audio, in Mechanicsville, VA. Reviews are good, including the several I've read on headlights. I'll post my results here, after the late December appointment date.

Truck details are to the left of this sentence... From what I've read, "blinding other drivers" only occurs when a headlight system is incorrectly modified. That's another reason I'm hiring technician's with experience. The shop labor charge includes some dismantling on the passenger's side, accurate re-alignment, and the lifetime warranty on the bulbs. Worth it, to me, but your MMV.

Thanks a ton for the detailed reply. I'm having this done at a shop, so I will make sure they properly aim the LED's after installation. I'm anxious for this to be done, as the OEM halogens truly are garbage!

Bump... I've read about the HID's, but am still wondering about an LED conversion. Thanks!

After poring through the various options for a headlight improvement, one thing became certain...I'm not going to tackle this myself! So, I found an audio shop in Richmond who, interestingly, also specializes in lighting...specifically headlight modifications. The guy I spoke with sounded familiar with the GM problem during these years, and explained the fix they use: GTR Ultra 2 LED bulbs, $200 for a pair and $95 labor. I don't mind the price, considering it my punishment for not doing it myself, but I'm wondering if this will give me a dramatic headlight improvement. Has anybody tried this modification and, if so, are you happy with the results?

Thanks for the link, JimCost. Seems a tad pricey, but I should be used to that by now!

Also, despite removing the two screws on the bottom, the piece was very resistant to removal. Any disassembly tricks that I am not seeing?