2009 Yukon Transmission noise/rattling when starting in reverse

[Jeff Amberg]

Recently took in my 2009 Yukon XL for a general check up prior to going on a long trip. Dealer recommended transmission and fuel system service.
Now I hear this grinding, rattling sound when I back it out of the garage in morning. Ambient temperature mid 70’s . The dealership replaced rear main seal housing gasket, replaced external/auxiliary trans cooler.
Also, downshifting tends to surge. I’ve also noticed that when slowing down, because of the surging, I’ll put the transmission in neutral, the engine throttles up to between 1500-2000 RPM.
Your thoughts are appreciated
Jeff

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

How many miles have you put on the truck since it was serviced at the dealer?

 

[Dustin Jackson]

Recently took in my 2009 Yukon XL for a general check up prior to going on a long trip. Dealer recommended transmission and fuel system service.
Now I hear this grinding, rattling sound when I back it out of the garage in morning. Ambient temperature mid 70’s . The dealership replaced rear main seal housing gasket, replaced external/auxiliary trans cooler.
Also, downshifting tends to surge. I’ve also noticed that when slowing down, because of the surging, I’ll put the transmission in neutral, the engine throttles up to between 1500-2000 RPM.
Your thoughts are appreciated
Jeff

@Jeff Amberg For the rattling, there is a heatshield near the shifter linkage on the transmission, when I had mine service the heatshield was bend and touching the transmission causing a rattling, all I had to do was get someone to operate the Tahoe while I touched things until the rattling stopped and then used a random tool to bend the heatshield back. this would be the first place I would look for that rattling.

I cannot speak for the rest of the symptoms you are having

 

[Doubeleive]

Recently took in my 2009 Yukon XL for a general check up prior to going on a long trip. Dealer recommended transmission and fuel system service.
Now I hear this grinding, rattling sound when I back it out of the garage in morning. Ambient temperature mid 70’s . The dealership replaced rear main seal housing gasket, replaced external/auxiliary trans cooler.
Also, downshifting tends to surge. I’ve also noticed that when slowing down, because of the surging, I’ll put the transmission in neutral, the engine throttles up to between 1500-2000 RPM.
Your thoughts are appreciated
Jeff

sounds like they did a bit more than just a trans service and fuel system service? because you then state :rear main & trans cooler? this means the transmission was removed and re-installed
at any rate depending on the condition of the transmission and previous transmission services doing a flush can dislodge material that then gets into places it wasn't before and then you have a problem, bottom line transmission flushes being done at high mileage and not on a regular basis can in some cases be risky I would speculate if you are under 80k then you might be ok. yes the owners manual says up to 100k intervals but that all depends on how it was driven and how long it has been. I always recommend a annual flush even if you only drove down the street and back.
if the noise is indeed coming from the transmission then you will need to have it pulled out and inspected (at the very least) and most likely rebuilt in some fashion depends on how much damage there is inside. guessing and asking online what do you think it is? well it's the transmission sir.
Transmissions have a lot of parts inside, high fluid pressure and very tight tolerances even a small spec of metal can cause problems.
report the problem to the dealer that serviced it and see what they find.
having the transmission pulled out and inspected typically runs about $500 but most places will apply that cost towards a rebuild.
good luck.

 

[Doubeleive]

I will add the rattling noise could be a heatshield as mentioned and the surging in neutral could simply be the fuel system still being dirty or relearning from the service, if they did the injector service only and missed cleaning the throttle body or maf and no new air filter you could be having idle issues.

 

[Joseph Garcia]

I will add the rattling noise could be a heatshield as mentioned and the surging in neutral could simply be the fuel system still being dirty or relearning from the service, if they did the injector service only and missed cleaning the throttle body or maf and no new air filter you could be having idle issues.

I was thinking about the transmission relearn as well, and that is why I asked the OP how many miles have been driven on the truck since the relearn.

 

[Doubeleive]

I was thinking about the transmission relearn as well, and that is why I asked the OP how many miles have been driven on the truck since the relearn.

the shop I go to said any trans relearn should be worked out by 50 miles

 

[Fless]

How does the fluid look, and is the level correct when hot?

 

[Jeff Amberg]

Fluid level was nearly empty, I had to add 2 quarts

 

[Fless]

Fluid level was nearly empty, I had to add 2 quarts

So did that change anything for the noise or surging?