2007 Denali transmission question.

[double e]

how did anyone get this tranny/hestiation problem fixed? A tranny tune?

thanks.

 

[makristal]

Hey All,

Sorry to bring back a dead thread! I'm new to the Yukon Scene! Just bought a clean 2007 Denali XL that I just ticked over 100k. I noticed today (probably because I was just listening to the car without music) that if I shit out of Reverse to Drive, and vice versa, that it shifts pretty hard. I am going into the shop on Friday to do a transmission fluid flush/fill so I'm hoping that it'll help the problem. Anyone else experience this ontop of the other issues stated?

What I feel in total:

• "Aggressive" shift out of first when granny driving
• "Aggressive" shift out of second when granny driving
• Hard clunk into Reverse from Drive
• Hard clink into Drive from Reverse
• Transmission temp seen up to 180 degrees Fahrenheit

Any help would be awesome!

Otherwise I LOVE this truck!

 

[OneTwo]

Hey All,

Sorry to bring back a dead thread! I'm new to the Yukon Scene! Just bought a clean 2007 Denali XL that I just ticked over 100k. I noticed today (probably because I was just listening to the car without music) that if I shit out of Reverse to Drive, and vice versa, that it shifts pretty hard. I am going into the shop on Friday to do a transmission fluid flush/fill so I'm hoping that it'll help the problem. Anyone else experience this ontop of the other issues stated?

What I feel in total:

• "Aggressive" shift out of first when granny driving
• "Aggressive" shift out of second when granny driving
• Hard clunk into Reverse from Drive
• Hard clink into Drive from Reverse
• Transmission temp seen up to 180 degrees Fahrenheit

Any help would be awesome!

Otherwise I LOVE this truck!

Drive to reverse (and vice versa) clunk could be driveline play. U-joint, rear diff, front diff, etc. Still, it's not a bad idea to have the transmission serviced. I would just mention the issues you're having to the tech and ask him to inspect the driveline for excess slack while he's under the truck servicing the tranny.

EDIT: This thread getting dug up was actually very helpful. My '07 Denali does the EXACT same thing as many other described in this thread, but my trusted mechanic told me everything was fine. I've thought for the past few weeks that he must be mistaken; there was no way that everything could be fine. Reading this thread gave me some peace of mind!

 

[makristal]

Awesome thanks so much! Glad to see a Washingtonian on hand I have it going in Friday so I'll ask them to tighten up anything in the driveline as well

 

[Speck]

I'm on my second transmission with my 08 Denali and even with the second one it still does the same things as everyone else has mentioned. First transmission decinagrated while at the dealership for routine service at 70k miles. Thankfully it was replaced under warranty. They showed me the pan and it looked like pea gravel.

What part of Washington are you from @makristal?

 

[makristal]

Hey Speck, I'm over in Kirkland, WA. So interesting details to come! I went and got the tranny serviced, and they had no concerns aside from the fluid being a little darker than they would've liked to see. Totally, normal for a car where you don't know how much it was serviced. The Tech went the next step and contacted GM about my experiences and they sent him this GM Service Bulletin:

Bulletin NO: 99-04-20-002D
Subject: Information on Driveline Clunk Noise when shifting between PARK/DRIVE, PARK/REVERSE, DRIVE/REVERSE

If you can find the details, it highlights the problem to a the exact use cases and says this is completely expected behavior with this car. With the 6.2 Allison engine, I'm not sure if it's hooked up to an Allison transmission, but the tech's at my shop were pretty confident it was solid (knock on wood).

 

[Speck]

Hey Speck, I'm over in Kirkland, WA. So interesting details to come! I went and got the tranny serviced, and they had no concerns aside from the fluid being a little darker than they would've liked to see. Totally, normal for a car where you don't know how much it was serviced. The Tech went the next step and contacted GM about my experiences and they sent him this GM Service Bulletin:

Bulletin NO: 99-04-20-002D
Subject: Information on Driveline Clunk Noise when shifting between PARK/DRIVE, PARK/REVERSE, DRIVE/REVERSE

If you can find the details, it highlights the problem to a the exact use cases and says this is completely expected behavior with this car. With the 6.2 Allison engine, I'm not sure if it's hooked up to an Allison transmission, but the tech's at my shop were pretty confident it was solid (knock on wood).

Hi Mike, glad to hear they didn't see anything major. I will check on that bulletin, but do know that we do not have the Allison transmission in our vehicles. The Allison transmission is a diesel transmission only for GM vehicles right now (to my knowledge). I do know that we have the 6L80E transmission, which is supposed to be a very good transmission, but has had its own set of issues i.e. clunks, hard shifts, and not shifting when it should.

I look forward to seeing pictures and progress on your truck! Welcome to the boards, and it is very addictive once you get bit by the mod bug! I'm in Olympia as well, so we will have to try to get a Washington/Oregon get together going or something...

Joe