HELP ME!!!

Usually if the rear brakes are stuck, as soon as you try to go forward the rear of the truck will squat. I know my truck or any of my vehicles will do that if I forget to release the parking brake.

Axm1096 said:

I hope its its something simple like that what are the symptoms of a failing transmission or does it just give out

Click to expand...

Transmissions have lots of failure modes, but slipping is one of the most common. When a transmission slips it feels like the car is in neutral. The engine will rev freely but the car will barely move, if at all. I rebuilt a ZF 5HP24 on my bench a few years ago. The A-clutch drum snap ring groove failed, causing the transmission to slip in both first gear and reverse. What makes me think that's not your problem is that you have motion in reverse but not forward. Reverse typically uses the same clutch pack as first gear but adds one more gearset in addition, so if your first gear clutch pack or solenoid failed, you wouldn't likely have reverse either.

Axm1096 said:

I have a 2007 Yukon denali AWD when i shift from park into drive and i accelerate the truck feel like the emergency brake is on but on reverse its fine everything was working fine when i got home 2hr later when i tried to leave its when it happened no code's please help

Click to expand...

I've been there and I know what it feels like and it sounds like the hubs are starting to lock up in the front. I have a 2004 Yukon Denali it did the same thing. The Hub last anywhere from 60 to 100 thousand model usually

Try jacking it up, put it in neutral, and then try rotating each tire. See if you can narrow it down to one wheel that will not rotate or is difficult to rotate or at least one axle.

Axm1096 said:

I have a 2007 Yukon denali AWD when i shift from park into drive and i accelerate the truck feel like the emergency brake is on but on reverse its fine everything was working fine when i got home 2hr later when i tried to leave its when it happened no code's please help

Click to expand...

Do you use your parking brake?
If so, you could have a cable sticking or worn shoes!

Agree with Bigkevchopshop. The E-brake on your vehicle is a drum brake system that is integrated on the inside "hat" of your rear rotors. I would take both off and check for damaged parts that may be the cause of binding.

BTW, just saw this post about "e-brake noise":


https://www.tahoeyukonforum.com/thr...medium=email&utm_campaign=ed1461#post-1512283

Axm1096 said:

I have a 2007 Yukon denali AWD when i shift from park into drive and i accelerate the truck feel like the emergency brake is on but on reverse its fine everything was working fine when i got home 2hr later when i tried to leave its when it happened no code's please help

Click to expand...

Get her up in the air and pulls the wheels and inspect the brakes. You may need a puller to remove the rear rotors as they also contain the parking brake shoes. Join AllDataDIY so you have access to the shop manual and will know how to adjust the parking brake actuator and shoes if necessary. Make sure the pads move freely on the slides and that the pistons are working properly.

I did the front brakes, everything but the calipers as they were working fine and then a year later one piston hung up one day. Fixed it and everything was fine for another few months and then one day it got stuck and took out the pads and rotor. Had to replace everything again and just for good measure I rebuilt the rear calipers too and then used 6 quarts of brake fluid to get all the old stuff out and bleed the brakes properly.

If you are going to DIY and self-diagnose this truck, you absolutely need a Tech-2 or equivalent, not a code reader, but the same tool the dealership uses to work on these things. It quickly pays for itself and is the most important tool in your toolbox.

As for the transmission, most of the time, the first sign of trouble with the 6L80 is that the solenoids need rebuilding which you can do on your kitchen table for about $100 plus fluids. This generally occurs at around 160K miles. Same for the oil pump pick up tube o-ring.

Thank you everyone for your suggestions the denali need a new transmission started winning and grinding at idle in park lost completely reverse and slips in drive so off to the transmission shop so unfortunately during all this covid and holidays around the corner again thank you all for your response have a great Thanksgiving and stay safe

Axm1096 said:

Thank you everyone for your suggestions the denali need a new transmission started winning and grinding at idle in park lost completely reverse and slips in drive so off to the transmission shop so unfortunately during all this covid and holidays around the corner again thank you all for your response have a great Thanksgiving and stay safe

Click to expand...

Sucks that your transmission has failed, but now you at least have a diagnosis and can move forward.

wjburken said:

Sucks that your transmission has failed, but now you at least have a diagnosis and can move forward.

Click to expand...

Literally, after repair. I see what you did there.