2015 Silverado issue

Truck has 99,000 miles. About 2 1/2 weeks ago a low frequency noise started at 62-65 mph. Slower or faster, no sound. Kind of a rumble noise but no noticeable vibration or shaking. Got it into my mechanic last Monday and he couldn’t find anything. Thought it was tire noise since one had some cupping. Had tires rotated and balanced and still did it. Brought it back in and another mechanic road with me to hear the sound. Easily reproduced at 62-65 mph. Put it on the hoist and checked it over looking at wheel bearings/drive shaft/u-joints. Didn’t find anything except all 4 tires were worn on the inside edge of the tread. Still thinks it’s tires. Had new tires put on (Michelin LTX MS-2) and it still does it. May be getting a little louder. Same mph range. Taking it back in Tuesday morning.
Over the winter I cut ~20 dead/infested ash trees and piled the wood up since the city drop off was closed. Hauled it all in when it opened in March and maybe I overloaded it and damaged the rear wheel bearings.
Any thoughts/ideas or things I can check? I’m bummed because this is preventing me from heading up north fishing this week.

Only thing I can think of is on our old Chevy company trucks of that era my co worker fought a mystery noise like this for a long time . There was a rubber weather strip looking deal between the rocker panel and running board that got loose and vibrated in the wind . Are door seals good ? Bug deflector ? Bed cover ? Does it go away with different wind directions ? Good luck – that kinda stuff can drive a guy nuts !

Chevy had a transmission shudder issue for a period of time. It felt like you were driving over rumble strips. There is a tech bulletin out on it. The fix is to flush your tranny and change to a different viscosity fluid.

I wouldn’t necessarily let it prevent you from going up north, but I hope you find a remedy.

I doubt its a tranny shudder issue because I would never have that happen at those speeds. It was always in the 30s.

Could be a hundred different things. I’d suggest getting a second opinion from another mechanic.
If they can’t find anything either it’s not bad enough to keep you home, go fishing.

Netguy does the noise change pitch if you steer one way or the other ie going around a slight corner? My guess would be wheel bearing but they are hard to miss for a decent tech. I know I’m the other end of town but would be happy to help if you want to make it up to me. Could also be a bearing in the rear end. The specific speed it occurs is kinda weird though.

John my initial thought was wheel bearing too. Should be easy to diagnose.

It’s the fishing gods telling you to go fishing.

My Camry had a noise from 45-65 mph, that got worse, and transformed into shaking at that speed range. I took it to the mechanic after changing the wheel bearings and the mechanic confirmed that the axle was bent slightly, causing the shake and noise. Might be that as well. I had the front axle replaced and it runs like the day I bought it now.

Had a similar noise at a set speed, ended up my drive shaft was wobbling at the right speed.

bigcrappie wrote:

Had a similar noise at a set speed, ended up my drive shaft was wobbling at the right speed.

Good point! I remember there being an issue with the drive shafts not being balanced properly around that timeframe.

My wifes CRV had a weird vibration/groan at certain speeds. The couple mechanics we talked to couldn’t find anything wrong but said it’s possibly a bearing around the torque converter, transmission going out, or something in that area. Which was somewhat common in that vehicle. Said it could be a couple grand just to diagnose. Car was only worth 5-7k. Ended up trading it in and being done with that potential headache before it ended up costing us more than it was worth.

Thanks for all the suggestions. If it was an out of balance drive shaft, why would it show up now?
Anyway this morning it looks like the mph range is broadening but it’s still the loudest at 62-65 mph.
I checked out the from air damn and that was solid. The plastic skid plate (still can’t believe it’s not aluminum) looked like the outside edge in front on both sides was going up and hitting the frame. Zip tied a piece of swim noodle on it and nothing changed. That would have been one of my best MacGyvers yet.

I have had a rumble on a couple vehicles that ended up being universal joint issues. Once it was a rumble only when braking and the others was a some noise and shake at a certain speed. I have the small universal joint press so I was able to change them in my garage

I did try swerving side to side to see if the noise changed but it didn’t. Glad there wasn’t a smokey behind me since I was changing lanes at 64 mph on 494. Might have been a field sobriety test.
Did this Sunday evening shortly before dark when the traffic had diminished.
I’ll definitely let the mechanic know about the TSB for this:

yooper2 wrote:

Chevy had a transmission shudder issue for a period of time. It felt like you were driving over rumble strips.

That’s pretty much how I described it. Like going over rumble strips but very faint. Yesterday I noticed it between 20-30 mph, like rumble strips. I also ran it at 64 mph using the M5 transmission mode to keep it out of 6th gear and it still did it.
Bringing it back in 30 minutes, wish me luck. A couple buddies limited on Winnie yesterday, dang!!

Ok now I think I know what your talking about, I’m afraid your having a torque converter starting to fail. Take it somewhere you trust that has good transmission knowledge. We have fixed one by just replacing the converter and having a rebuilder go through the trans. Is yours a 6spd or 8spd?

Netguy if you want to call me at the shop I can try to be more helpful. Sucks this is getting in the way of you getting out.

Victory Auto Service 763-780-1002

Could be a cracked flex plate also… if its easily duplicated, tell the mechanic to use the chassis ears.

On my f-150 I had a slight vibration when letting off the gas going over 70mph. It ended up being the hanger bearing on the drive shaft. Ford sells it as a complete assembly so new drive shaft, hanger bearing and u-joint. Hope you get it figured out soon.

6-speed

I had the exact thing in my 2015 and it was the torque converter. I believe the flush “fix” is for the 8 speed. The dealership said they could rebuild the torque converter but for a similar price, longer warranty and no guessing if other tranny parts were compromised, I had a transmission shop rebuild the entire thing. I had more places suggesting to rebuild the entire tranny to be safe than just the torque converter.

My buddies 2018 8 speed tranny did the same thing. He tried the flush, didn’t work and ended up doing a rebuild as well.

4 mechanics drove it and 3 heard the noise. The owner admits his hearing isn’t the best. They looked at a bunch of things under the truck: brakes, suspension, steering, drive train, wheel bearings and couldn’t find anything definitive to go after. No codes present. They might not even charge me for their time since nothing was written up when I picked the truck up. I have been a loyal customer with several vehicles for ~15 years.

John, I’ll give you a call in the morning. What time? I’ll also send you a PM.
I’ll start looking for transmission shops. Go for one of the big guys Kennedy/Aamco or any recommendations on the west/soutwest side of the cities?

Oh, 3 friends caught 40-50 eyes on Red today. I should be there too. Double dang!!

To eliminate a torque converter clutch issue, slightly press the brake while maintaining pressure on the throttle. A good mechanic with a scanner should see the slip on the scanner if the converter was the issue

beardly, which transmission shop did you use?
My brother has had good work done and been satisfied at Kennedy in Plymouth. That is close to me.

Just had a pleasant conversation with John Rasmussen. Gave me plenty of info and the name of a transmission shop he recommends.
Thanks John!!

Yeah the torque converters are known to be a problem in these things along with the shudder, they are probably both related, but I am no mechanic. My wife’s tranny locked up and it was a catastrophic internal failure per the code. They put a reman tranny in it with a billet torque convertor which is supposed to be nearly bullet proof.

Netguy wrote:

beardly, which transmission shop did you use?
My brother has had good work done and been satisfied at Kennedy in Plymouth. That is close to me.

Eric Transmission Repair near Elko.

Netguy wrote:

Just had a pleasant conversation with John Rasmussen. Gave me plenty of info and the name of a transmission shop he recommends.
Thanks John!!

Happy to help

As a guy who just had his tranny crap out by Blackduck and limp it back to Bemidji for a new one imo it’s a good call to fix the issue now.