How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask FIX IT MAN Your Own Question
FIX  IT MAN
FIX IT MAN, Master Technician
Category: GMC
Satisfied Customers: 17368
Experience:  Master Automotive Technician
1627031
Type Your GMC Question Here...
FIX IT MAN is online now
A new question is answered every 9 seconds

Gmc Yukon Denali: I HAVE QUESTIONS ABOUT THE TRANSMISSION IN

Customer Question

I HAVE QUESTIONS ABOUT THE TRANSMISSION IN A GMC 2007 YUKON DENALI. IT HAS A 6.2 ENGINE AND A 6L80 TRANSMISSION
Submitted: 2 years ago.
Category: GMC
Customer: replied 2 years ago.
I have a 2007 GMC Yukon that started to slip out of 1st gear. If you let of the gas and slowly accelerate it will go into 2 3 and so on and drive normally. but when you slow down or come to an stop it will exibit the same behavior over again getting worse has you drive further. I have searched the internet and seem many people with the same or similar symptoms but no definite answer on what it could be.
the transmission is currently out the vehicle and disassembled. I have checked all the clutch frictions and steels and don't see any problems.
2007 GMC YUKON DENAL AWD
6.2 L ENGINE
6L80 TRANSMISSION
Customer: replied 2 years ago.
(Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Tims Auto Repair replied 2 years ago.
Hi, My name is ***** ***** for the delay.I will do my best to assist youdoes the engine light stay on?if so,can you give me the computer codes?does reverse work well?
Expert:  Tims Auto Repair replied 2 years ago.
how many miles is on the truck?
Customer: replied 2 years ago.
yes engine light stayed on mileage 108000
revers works fine
codes p0700 & p2723
Expert:  Tims Auto Repair replied 2 years ago.
ok,stand by,,let me check these codes
Expert:  Tims Auto Repair replied 2 years ago.
are you sure it has the 4l80?
Customer: replied 2 years ago.
no it has the 6l80
Expert:  Tims Auto Repair replied 2 years ago.
ok,,stand by
Expert:  Tims Auto Repair replied 2 years ago.
okfrom te way you explain,,and from the codes you get..i think you may have a major problem here
Expert:  Tims Auto Repair replied 2 years ago.
with it slipping and the 700 and the 2723,,i think the problem is internal and the transmission may need to be rebuilt or replaced
Expert:  Tims Auto Repair replied 2 years ago.
it is possible for it to be the valve body/solenoids,,but,,i think it may be internal
Customer: replied 2 years ago.
I have a 2007 GMC Yukon that started to slip out of 1st gear. If you let of the gas and slowly accelerate it will go into 2 3 and so on and drive normally. but when you slow down or come to an stop it will exibit the same behavior over again getting worse has you drive further. I have searched the internet and it seems many people have the same or similar symptoms but no definite answer on what it could be.
the transmission is currently out the vehicle and disassembled...... I have checked all the clutch frictions and steels and don't see any problems.
2007 GMC YUKON DENAL AWD
6.2 L ENGINE
6L80 TRANSMISSION
Expert:  Tims Auto Repair replied 2 years ago.
stand by,,i am going to upload tests/checks for these codes
Customer: replied 2 years ago.
I was wondering if someone had found a DEFINATE cause for this problem since it is so common
Expert:  Tims Auto Repair replied 2 years ago.
ok,,i will opt out..stand by
Customer: replied 2 years ago.
ok
Expert:  FIX IT MAN replied 2 years ago.
Hello, my name is Bobby. Thank you for the question. You are right that this is a common issue on this transmission. Almost every time I have seen this it is due to a small crack in the 1-2 clutch housing. If you take a really close look at the internal area of the housing you will usually see it. It is not always easy to see. This crack allows flexing which causes this shifting problem. If it is definitely fine then the next most common is the control module calibration. If it does not have the most up to date calibration then this will occur. I hope this helps. Let me know if you need more help.
Customer: replied 2 years ago.
do you have any images or examples or link to of what I should be looking for
Expert:  FIX IT MAN replied 2 years ago.
This service bulletin has some pictures the show the areas that you need to look at.

Related GMC Questions