General Motors has issued a customer satisfaction program for certain examples of the 2020 and 2021 model-year Chevy Silverado HD and GMC Sierra HD over issues related to the transmission oil cooler jumper lines.
The problem: certain 2020-2021 model-year Chevy Silverado HD and GMC Sierra HD trucks may have a condition in which the transmission oil cooler jumper line has a leak at the crimp.
The hazards: while this problem poses no direct safety hazard to the driver or vehicle occupants, owners will still want to bring their vehicle in for repairs, as the problem may result in fluid leaks that could cause further transmission troubles.
The fix: GM dealers will be instructed to replace the transmission cooler inlet and outlet pipe and also the jumper line. They will also fill the vehicle with new Dexron V transmission fluid.
Affected components: transmission oil cooler jumper line, transmission oil cooler inlet and outlet line assembly.
Affected vehicles:
Number of affected vehicles: it’s currently not clear how many vehicles may have this condition. This problem only affects Chevy Silverado HD and GMC Sierra HD trucks equipped with the gasoline 6.6L L8T V8 engine and not the optional Duramax 6.6L L5P V8 turbodiesel.
GM 6.6L L8T V8 engine
Next steps: owners of affected Chevy Silverado or GMC Sierra trucks will most likely be instructed to make an appointment with their dealership to have the transmission cooler lines inspected and replaced. Owners with additional questions or concerns can also reach out to Chevy or GMC directly using the contact information included below.
Contacts:
- GM Customer Satisfaction Program number: N212324960, N212329461
- Chevrolet Customer Service: 1-800-222-1020
- GMC Customer Service: 1-800-462-8782
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Comments
Dexron VI. There us no V.
It would be nice if GM would fix there 8speed transmissions instead of saying it is normal when my transmission clunks an shudders when it under full warranty. Shame on you GM.
There is a fix for it. They need to change the fluid. Its been all over this site. There is a TSB for it. Maybe have your dealer into it for you.
Another reason to love the Diesel.
Now add all previous years and subsequent ones for the duramax and it will be correct.
I lost my 2021 Chevrolet 2500 hd ltz in Oklahoma, I’m from Ohio.. my wife and I went on vacation to see two of our daughters 1 in Oklahoma in Texas. My 2021 ltz had 5055 miles on it monitor display keep. Coming on several different messages keep coming on I called onstage, they said no problem Code was c1209 wheel left speed sensor.. I lost my steering n my breaks keep locking up got it to a dealership 6 days they couldn’t find what the problem was. The 7th day I was out of meds. my wife was two day’s late for work so the dealership offered to trade in ,well I’m stuck with a Tahoe which ain’t 1/2the truck my Ltz was … just wandering is this a Chevrolet problem?
Anyone who drives a GM deserves what they get. It’s so obvious by now GM makes junk, and has for years. But you have white males who, “only drives American”. And refuse to buy Asian.
Asian trucks are no better or worse. All vehicles have problems. And since you dont’ like GM kindly remove yourself from this site.
If you don’t like chevys why are you on this site?
I have 2014 gmc. No issues at all 61,000 miles
My 2019 RST Silverado had same issues with crimping oil lines, was found while in for other warranty work.
2014 Silverado he
289,000 mikes. Still going strong. Maintenance maintenance maintenance. Like anything is jey
I would be happy if they would put out a SB or recall to stop the damn transmission line on my 2013 3500HD from rubbing through the line and requiring a new one ever 2 years. A pool noodle might be in order because there are no retaining available to help hold it secure.
Just replaced trans cooler line on my 2020 3500, with 86k miles. Leaking trans fluid. This is not right. This line should last forever. 700.00 out of pocket exp., I bought a fully warranty, wouldn’t pay for it. This is a gotcha moment. Owned every type truck out there. This sux.