Rattle when slowing down

[kinzerhaus3]

Got a puzzling one here. 2018 Silverado Eassist 8 speed auto that I have had numerous weird issues with since day 1. The latest is what sounds like a nut or socket rolling in the bed when you Slow down. The bed is clean. After much trial and error I can finally get it to duplicate reliably.

 

Get speed up past 40 -45

Slow down with extremely light pressure on the brake pedal.

At 27mph when the transmission downshifts you hear the rattle that sounds like a nut rolling about 6 inches in the bed

You do not hear the noise on acceleration

Too hard on the brake - noise is very soft

Slam on the brakes - no noise

Coast to a stop- no noise

Pushing down on the brake pedal what feels like 1/4" - noise is loud

 

Things they have done to the truck:

Changed transmission fluid and updated software multiple times over the first 30000 miles to fix harsh shifts

Replaced the valve body in the transmission about 5000 miles ago due to extremely harsh shifts. So harsh it rattled all the screws loose in the overhead bin and it fell out of the ceiling.

Dealer discovered there was extremely low fluid in the rear end about 2000 miles ago. Said it leaked out and I must tow a lot (I don't tow anything) LOL. Issue had been my main complaint from day 1. Symptoms were a shudder in reverse at low speed. 100 miles left on the warranty when they finally figured this out.

 

Noticed the rattling noise after they replaced the fluid and honestly though they left a socket on the spare or in the frame.

Took it back in 1000 miles later as the reverse shudder was still there and reported the noise. Diagnosis was noisy leaf springs we will grease the fronts

Dealer replaced the rear end center section since it still had the reverse shudder. (Of course it was bad it had low fluid from day 1 and it now has 37000 miles on it)

Still has the same rattling noise and now I can make it happen at will

Just finished reading another post here and they mentioned trash in the valve body. So I am going to try to make the noise happen with the truck in neutral and will update later

Any ideas?

 

Thanks!!

[kinzerhaus3]

Have tried several times to duplicate the rattle when the truck is slowing down with the transmission in neutral. It does not rattle when the transmission is in neutral only when the truck is in gear

[kinzerhaus3]

Dropped the truck off a week ago. The dealer called to tell me it was the transmission, but they dont know exactly what yet. Tech that rode with me when I duplicated the noise multiple times told me it was transmission and yet it took them a week to let me know the same thing. Not sure they have a clue or are they stalling because they are working on other stuff.

 

[ThaBoss]

Sorry to revive an old thread, but what ended up being the issue? My 2016 with e-assist is doing the exact same thing and the dealer hasn't been able to figure it out for 2 months now.

[Croffocc]

I was looking to see if there are any updates as well.  I have a 2017 eassist that is doing the same thing.   Light brake and rattles between 25-30 mph. 

[GMCustomerService]

15 hours ago, Croffocc said:

I was looking to see if there are any updates as well.  I have a 2017 eassist that is doing the same thing.   Light brake and rattles between 25-30 mph. 

We are sorry to hear that you are facing these concerns with your vehicle and would like to help investigate further for you. Please send us an email to [email protected]. Be sure to include your Username and Forum name in the subject line with additional details. We look forward to hearing from you. 

[Nicholson]

Any updates on here fellas? My 2018 is doing the same thing. 

[GMCustomerService]

On 9/22/2024 at 4:05 PM, Nicholson said:

Any updates on here fellas? My 2018 is doing the same thing. 

Our team regrets to hear of this concern you are experiencing with your vehicle, and we would like to take the time to learn more. Please send us an email to [email protected]. Make sure to include your Username and Forum name in the subject line with additional details. 

[GTAhockeydad]

Hi, i have the same issue with my 17 eassist. 

Sounds like a tin can rattling loud when light braking . 

 

Is there any solution to this. 

[Eric Devi]

Hey, my 17 Silverado is doing the same...sounds like a rattling heat shield with light brake apply. I checked over every single splash shield, heat shield and skid plate that I could..I shook down everything that I could and couldn't locate the noise. It also almost sounds like a rock or something between the backing plate of a caliper too, but it's not. Just would like to know what the OP found was the problem, and if it was internal to the transmission.

[MURPHY_]

On 2/14/2020 at 2:50 PM, kinzerhaus3 said:

has anyone figured out what causes this? 2017 silverado doing the exact same thing. 

[JimmyGqc]

Same here with my 2017 Sierra SLT e-assist. When slowing down, with no or light brake pressure at 40kmh : bad noise... Can't believe that no solution identified yet!

[Emanuel 2016 silverado]

Hi all,

 

I’m experiencing a similar rattling noise issue with my 2016 Chevy Silverado eAssist. About six months ago, I replaced the transmission due to bucking, kicking, and hard shifting. There was no rattling noise before the transmission replacement.

The rattling started after the remanufactured transmission was installed. I brought this to the transmission shop’s attention, and they agreed to replace the transmission again. I picked up the truck today with the second remanufactured transmission installed, but the rattling noise is still present.

At this point, I’m trying to determine whether this noise is actually transmission-related or if it could be coming from another component. Any insight or suggestions would be greatly appreciated.

 

I was able to record the noise. Just don’t know if I can upload here for the community to hear.