2007 GMC Yukon PLEASE HELP! Any info would be great - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Morfias4Twenty · 10-25-2010, 12:36 PM

Ok So I was driving at like 5 mph In a parking lot, when the wheels lock up hard, screeches on the pavement and the trucks starts rolling again, I stop to see if maybe I ran over something, I see nothing then Put it in drive and the trans won't engage, So immediately think " damn my transmission just went out". But I drop the shifter all the way down To 1 and it drives, then I shift it up to 2 and its still driving.. At a dead stop the transmission will engage On 1 and on 2, It will not engage on 3 or on D. BUT I can shift the transmission manually From 1 to 2 to 3 to drive and it will drive with no issue.. I also have to down shift it manually because if I don't once I'm at like 20 mph it won't catch. It will just rev like I'm in neutral. It also makes a vibrating screeching sound some times.. This just happened 2 days ago..
Am I making any sense? Does any one know what might be wrong? Has any one experienced this before?
again its a 2007 GMC Yukon with 79k on it

The Trans never slipped it always shifted nice and smooth, any info would be great..
don't really know if the trans is a 60 or an 80.. How can I find out?

Thank you all in advance
Roger

**Clyde65** · 10-25-2010, 02:53 PM

Any ses light? Have you a ODB scanner?

Might be in "limp" mode, the PCM uses that to protect certain aspects of the computer/engine systems.

Morfias4Twenty · 10-25-2010, 02:56 PM

No lights, nothing every things seem normal.. other than the fact that my auto is now a manual with 4 on the tree..lol

clinebarger · 10-25-2010, 04:38 PM

Forward sprag is broken, Transmission needs to be tore down & rebuilt.

Morfias4Twenty · 10-25-2010, 05:26 PM

Quote:

Originally Posted by clinebarger

Forward sprag is broken, Transmission needs to be tore down & rebuilt.

Thanks Clinebarger, Have u had similar situations? I have powertrain warrenty do you think that would cover it?

clinebarger · 10-25-2010, 05:36 PM

Quote:

Originally Posted by Morfias4Twenty

Thanks Clinebarger, Have u had similar situations? I have powertrain warrenty do you think that would cover it?

Ive rebuilt several units that have had this problem. Your warrenty should cover it.

**Clyde65** · 10-25-2010, 05:38 PM

yes it should but be sure to read your policy prior to taking it to a dealer. also depends on the mileage ( compared to warranty mileage) as to your deductible I believe.

http://www.gm.com/vehicles/warranty/....html?page=faq

Morfias4Twenty · 10-26-2010, 12:52 PM

Guys thanks a bunch, I talked to GMC and it will be coverd at no cost!!
this powertrain warranty is the BOMB!!!
clyde65 that link was very helpful.. thank you

10-25-2010, 12:36 PM	#1
Morfias4Twenty Registered User Join Date: Jul 2009 Location: Saginaw, Texas Posts: 268	2007 GMC Yukon PLEASE HELP! Any info would be great Ok So I was driving at like 5 mph In a parking lot, when the wheels lock up hard, screeches on the pavement and the trucks starts rolling again, I stop to see if maybe I ran over something, I see nothing then Put it in drive and the trans won't engage, So immediately think " damn my transmission just went out". But I drop the shifter all the way down To 1 and it drives, then I shift it up to 2 and its still driving.. At a dead stop the transmission will engage On 1 and on 2, It will not engage on 3 or on D. BUT I can shift the transmission manually From 1 to 2 to 3 to drive and it will drive with no issue.. I also have to down shift it manually because if I don't once I'm at like 20 mph it won't catch. It will just rev like I'm in neutral. It also makes a vibrating screeching sound some times.. This just happened 2 days ago.. Am I making any sense? Does any one know what might be wrong? Has any one experienced this before? again its a 2007 GMC Yukon with 79k on it The Trans never slipped it always shifted nice and smooth, any info would be great.. don't really know if the trans is a 60 or an 80.. How can I find out? Thank you all in advance Roger __________________ ......................_____ .........________//__{\_____ ,,,,,,,,,/__(O)__/____/_(O)_/ 1967 C-10, 383 1975 C-10, 454 SWB Buckets Low and Slow Baby!

10-25-2010, 02:53 PM	#2
Clyde65 1965 Chevy C10, 2005 4.8L/4l60 Join Date: Aug 2004 Location: DFW Texas Posts: 8,539	Re: 2007 GMC Yukon PLEASE HELP! Any info would be great Any ses light? Have you a ODB scanner? Might be in "limp" mode, the PCM uses that to protect certain aspects of the computer/engine systems. __________________ Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 *support our troops!*

10-25-2010, 02:56 PM	#3
Morfias4Twenty Registered User Join Date: Jul 2009 Location: Saginaw, Texas Posts: 268	Re: 2007 GMC Yukon PLEASE HELP! Any info would be great No lights, nothing every things seem normal.. other than the fact that my auto is now a manual with 4 on the tree..lol __________________ ......................_____ .........________//__{\_____ ,,,,,,,,,/__(O)__/____/_(O)_/ 1967 C-10, 383 1975 C-10, 454 SWB Buckets Low and Slow Baby! Last edited by Morfias4Twenty; 10-26-2010 at 12:39 PM.

10-25-2010, 04:38 PM	#4
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: 2007 GMC Yukon PLEASE HELP! Any info would be great Forward sprag is broken, Transmission needs to be tore down & rebuilt.

10-25-2010, 05:38 PM	#7
Clyde65 1965 Chevy C10, 2005 4.8L/4l60 Join Date: Aug 2004 Location: DFW Texas Posts: 8,539	Re: 2007 GMC Yukon PLEASE HELP! Any info would be great yes it should but be sure to read your policy prior to taking it to a dealer. also depends on the mileage ( compared to warranty mileage) as to your deductible I believe. http://www.gm.com/vehicles/warranty/....html?page=faq __________________ Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 *support our troops!*

10-26-2010, 12:52 PM	#8
Morfias4Twenty Registered User Join Date: Jul 2009 Location: Saginaw, Texas Posts: 268	Re: 2007 GMC Yukon PLEASE HELP! Any info would be great Guys thanks a bunch, I talked to GMC and it will be coverd at no cost!! this powertrain warranty is the BOMB!!! clyde65 that link was very helpful.. thank you __________________ ......................_____ .........________//__{\_____ ,,,,,,,,,/__(O)__/____/_(O)_/ 1967 C-10, 383 1975 C-10, 454 SWB Buckets Low and Slow Baby!



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