07' Denali- Transmission Issues- Any help?

[Filthy]

I just purchased an 07' Denali w/ 161k miles. Purchased via a dealer auction, and was able to drive it prior to taking delivery. Super Clean, and Super Nice...and on the initial test drive...it drove like new as well. Thought I'd put my wife in it, as a daily driver taking the kids back and forth to school. Driving it around this weekend, I started noticing sluggish shifts from 2nd to 3rd gear. after about 30 minutes of in town driving, it started to get a little more pronounced....and was definitely slipping. Mostly from the 2/3 shift...motor would rev higher before engaging. Obviously a little concerned, but nothing that was going to leave me stranded. Then, once we went to eat dinner, I decided I was going to back it into a parking space. NOPE! No reverse. I shifted it into reverse, and nothing happened. I gave it some gas...and then it finally engaged into reverse. It was a very smooth/sluggish reverse. So, it didn't engage hard/with a clunk..it was a very smooth. But obviously...there's an major issue. I took it home, and parked it. Next morning, got it and drove it around, and it shifted fine. Like New. So, I'm guessing, these issues are happening once it heats up/gets warm?


So, here's my long winded question/cry for help. Am I probably looking at complete transmission replacement? Rebuild/Removal? Or do the symptoms listed, give me ANY hope for a simple additive/fluid fill/change and go on down the road? Being that it shifts fine, and performs excellent upon initial start up, for the first 10+ minutes or so, do I have false hope in hoping that it could be something as simple as worn bands, that could be replaced at a minimal cost? Am I looking at a $500+ repair, or a $3,000 rapair?

any response is appreciated.

 

[Filthy]

Just curious to know if there were any opinions, good or bad, or any thoughts at all, before I go pay the dealership $99 to give me one.

Thanks!

 

[swathdiver]

During some internet searches the other day, I came across the words dreaded 2-3 shift in relation to our trucks. I didn't read them as I was looking for something else. Having said that, it seems to me that it's ready for an overhaul and new ones are around $2500 and a local rebuild including labor somewhat the same. Now you know why the previous owner sold it.

If you're mechanically inclined, you can do it yourself and save a bundle but maybe not, time is money as you know.

 

[RichardCranium]

Worst case scenario, the drum for those gears has a crack. More than likely its just badly worn clutches though.

If you can do the trans swap yourself or with the help of friends, it'll probably save you a little cash to buy a rebuilt tranny online. IMO, I'd find a local and reputable transmission shop to tear it down/rebuild it. In case there is an issue after the rebuild, it'll be far easier to deal with being close to you. The rebuild kit for a 6L80, complete with new seals/gaskets/clutches/etc, will cost about $1000 alone.....just keep that in mind up front (to avoid sticker shock for the estimate). I'd say a $3k ballpark will keep you sane when you get a shop to estimate it for you though.

 

[Meccanoble]

After my recent accident, I am experiencing tranny problems and did confirm dealership charges about 3500 for new everything installed. I would imagine an independent shop can swap a used tranny in there for way cheaper but i would be scared to spend this type of money and have issue 30k miles later. A new tranny is always a good way to go but they fail for a reason. I'm liking the rebuild option for 2 reasons. Should be cheaper than new with similar warranty protection, and maybe there is opportunity to make stronger than stock since its all being opened up. I'm still investigating but the rebuilt route (as expensive as it is) sounds like the best route in these situations.

Its tough because some days I think of fixing for as cheap as possible and getting rid of it but you looked at one at this mileage for a reason, $. And if you keep looking, you run the risk of same scenario. Dont think letting car go and investing that 3k into next car will put you in a better position than you would be with your current super clean truck and fully covered tranny. That 3k is frightening though.

 

[Hank Frederick]

Hi all sorry to steel the thread but I'm changing the trans fluid and filter in my 2007 yukon denali (100,000 miles) I was wondering if it is a good idea to add the Lucas trans additive while I'm changing it? Thank you

 

[swathdiver]

I plan to add it to one of my minivans and would not hesitate to add it to my truck if I thought I needed it. Unless of course, there is some good reason not too; for which I have not read.