Dmaxdanny

Forgot to add that in 9th. And 10th gear while driving the electrical malfunction light will come on. but as soon as it changes gears the light will go off. I’ve only pulled in active call a few times and it was just a low pressure code for the transmission

Need some help sorry I’m new to this form. I’ve replaced the clutch and throw out bearing in my mdrive about 2 years ago now. Other then that not very familiar with this transmission. I’m always finding air leaks on this truck but been chasing a few for a while. When driving at normal road speed if the truck is in 9th or 10th gear at about 1400RPM the “engine brake” / grade gripper will kick in and out and not hold the truck back it will hold in every other gear besides them. I’ve talked to people who say it could be a air solenoid in the trans but I just wanted to get some more information truck has 400k on it so trying to stay away from the savages at the dealer. Thanks for the help