2003 Yukon Denali Trans/electronic Problem (shifting & rpm)

[SnowDrifter]

Yikes

Check the electronical bits - check solenoids in the trans. Easiest way is with T2 or other high end scanner. If those are good, she's dead, Jim

 

[roveer]

Sure looks like your 2nd gear and 4th is GONE. That wavering rpm in OD is your 2-4 band slipping. I think you believe you arent getting 4th because you are counting 3 shifts when what it looks like is actual a 1st to 3rd shift (2nd gear is just slipping and never locks in) then a 3-4 shift and in there a torque converter lockup around 40-45mph which is easily confused as a shift. You are going to have to get those misfire and CPS codes figured out or you will be chasing your tail. That ****** Tech 2 will pay for itself! Mine has many times over and saved me so much time of having to deal with a garage..one that may or may not even get the problem fixed and still charge you for it.

Thank you for taking the time to analyze the videos. I knew there was nuance in what is happening. I'm probably going to get the scanner you are recommending since I have 4-5 similar gmc vehicles between a few family members. I'm looking now at reman transmissions. Turns out I have a leaking rear main seal that needs to be repaired and that would require the removal of the transmission, so I can economize on the labor by putting in a re-manufactured transmission after fixing the seal. Probably wouldn't consider doing any of this, but had just spent 3k rebuilding the entire front end steering linkage.

Thanks again for the input.

 

[roveer]

Yikes

Check the electronical bits - check solenoids in the trans. Easiest way is with T2 or other high end scanner. If those are good, she's dead, Jim

How exactly would I check these bits? Just look for codes, or would I have real time data running as I'm driving and watch for commands and shifts?

 

[rockola1971]

How exactly would I check these bits? Just look for codes, or would I have real time data running as I'm driving and watch for commands and shifts?

We are beyond that. 2nd gear is a slipping mess. 4th gear is slipping and will be gone soon. Both 2nd and 4th use different solenoids. If either of those solenoids were bad you wouldnt get either one of those gears but 4th is there but it just slips under load. Soon 4th will not be there and all this clutch slipping will ruin reverse clutches and dish their steel plates into frisbees due to the excessive heat. Then she dies a miserable horrible death. Pull tranny dispstick and I bet you will find that the fluid is no longer pink but more of a orange to burn brown and smells burnt.

 

[roveer]

Well... 3,300 dollars later and it's still a mess. Took it to a very reputable transmission repair shop with good reviews. Discussed the issues. They did a "rebuild". Kept it two extra days because they were having a problem. When I got it back it's having a problem going into second, and I believe into overdrive is somewhat similar. See the videos. My initial problems that started this whole thing were wonky shifts into 2nd and missing overdrive. The overdrive issue has been resolved with their rebuild. It's this funny shifting which leads me to believe something is slipping and will burn up the transmission in no time. Before I go back to the shop I'd like to have a little more information on what's happening. I'd be interested in your opinions. Also, does any of this

 

[mikeyss]

It sounds like the transmission pump itself is going bad, or your powering steering pump is howling. Did the transmission shop replace the front pump or torque converter?

 

[roveer]

That's the power steering pump. It's a rebuilt and I haven't bothered to change it. One thing I'll say, I always know when my wife is coming around the corner.

I'm not sure what they replaced.

 

[rockola1971]

Heres what I saw on the new videos. 1-2 shift and 2-3 shift. 3rd gear was slipping, thats why the rpm's were wavering during that shift. You didnt get up to speed for a 3-4 shift so I never saw 4th gear (OD). 3rd gear does NOT use a band in a GM so I would suspect the problem lies in the valve body. I cant believe they let this go out the door like that. An amateur transmission guy should have noticed the 3rd gear slip immediately. Why is your check engine light on? $3300 seems kind of high (but that may be what the market rate is in your area). Around $2200 for a 4wd GM fullsize truck/suv in my area for a complete textbook rebuild with new converter, all valve body updates, pump rebuild and standard clutch, steels and seals, new fluid and filter.

 

[roveer]

Heres what I saw on the new videos. 1-2 shift and 2-3 shift. 3rd gear was slipping, thats why the rpm's were wavering during that shift. You didnt get up to speed for a 3-4 shift so I never saw 4th gear (OD). 3rd gear does NOT use a band in a GM so I would suspect the problem lies in the valve body. I cant believe they let this go out the door like that. An amateur transmission guy should have noticed the 3rd gear slip immediately. Why is your check engine light on? $3300 seems kind of high (but that may be what the market rate is in your area). Around $2200 for a 4wd GM fullsize truck/suv in my area for a complete textbook rebuild with new converter, all valve body updates, pump rebuild and standard clutch, steels and seals, new fluid and filter.

Welcome to NJ... I'm sure I got none of those things you listed, just torn down and the minimum of parts replaced. I just noticed a full reman for 1,500.00 after core with all updates, plastic changed to alum etc... I was contemplating that route, but then decided against it since I'd be getting a tranny from someplace far away and what would I do if I had problems.

These guys were terribly old school. I kept mentioning the things I had learned about on-line but they didn't seem to want to talk about the worn out valve body and the Sonnax kits..

I'm going to do one more video on a nice hill from stop through 4th so we can see all the shifts. This way I can better understand what's happening. I believe there was some craziness going into 4th when I went up this hill which puts a nice load on the transmission. I'll post it later tonight.

Oh, and the shop listed it as a 4L60E when in actuality it's a 4L65E I checked the RPO code in the glove box and it's a M32 which decodes to a 65E. I hope that mistake didn't effect any parts they may have been changing.

 

[roveer]

OK, Not the best video. Let me know if I should take it out on the highway and open it up. This was up a hill, but I can't get going much faster than 50 on these roads.

Does look like it's 2nd to 3rd when the crazy tach jump happens. I was on the highway today and shifting into 4th seemed just fine. I'm really upset that this shop probably didn't even use a rebuild kit and just threw a couple of parts in to make it work. I did pay 3300 bucks for this work. From my previous post, the shop has it listed as a 4L60E and it is in fact a 4L65E, I looked up the RPO codes to verify 65E not 60E.

So what can you tell me about this problem for my 'discussion' with the shop owner? I'm assuming this is a slip and will eventually burn a clutch pack?

Check engine light is on for PO300 (multiple cylinder misfire) have to dig into that next. Seems like a very recent problem, and have never seen it before on this vehicle.

BTW, TPS sensor changed last month. Wondering about MAF sensor. Both have been written about to give bad shifts. I might have one on another GMC Yukon that I could swap in to test.