Transmission issues?

wilsondiesel

Member
Nov 11, 2015
190
0
16
Sedalia, MO
Has anyone seen transmission issues out of these? I have a customer that has a 2016, is having issues of no reverse engagement when parked on a hill. Fluid level and pressures are good. No codes. Truck is deleted are the only mods
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
Couple things I’ve had issues with on these. I’ve had sticking valves in the upper and lower valve body. I’ve also had the check ball get damaged and end up damaging the low reverse piston. The great thing about this trans is that after removing valve body assembly you can air check everything through the bottom of the case really easily.
 

wilsondiesel

Member
Nov 11, 2015
190
0
16
Sedalia, MO
Couple things I’ve had issues with on these. I’ve had sticking valves in the upper and lower valve body. I’ve also had the check ball get damaged and end up damaging the low reverse piston. The great thing about this trans is that after removing valve body assembly you can air check everything through the bottom of the case really easily.
Could you send me a screenshot of where to air check after removing the valve body? That would be the best way to check for a damaged reverse piston correct? Do you usually clean the valve bores like and Allison to unstick valves or just replace the whole valve body? Thank you for the info as I have found there is not much out there on these and my dealership hasn’t seen much either.
 

Mike L.

Got Sheep?
Staff member
Vendor/Sponsor
Aug 12, 2006
15,686
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Fullerton CA
If you have valves that are sticking, you have internal problems. Whatever is sticking those valves came from the inide, not the outside.
 

wilsondiesel

Member
Nov 11, 2015
190
0
16
Sedalia, MO
If you have valves that are sticking, you have internal problems. Whatever is sticking those valves came from the inide, not the outside.
Hey Mike, is there a way in these transmissions to tell if it’s sticking valves without pulling the valve body apart? It is not throwing any transmission codes.
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
Pressure switch readings 1,3,4,5 should all read Low when in reverse. If not, then you’d have to check for a shift solenoid or pressure control solenoid for being stuck on/off or exhausting when should be applying. A check ball damaged. sticking valve etc. If trans is not slipping at all or delayed/flared shifts then I’d bet it’s something in valve body or TCM. Double check shift Cable adjustment and make sure tight. Watch IMS readings as well and make sure each time you select gears it reads correctly. L,L,H,H for signal A,B,C, and P when in reverse. Has pan been dropped at all to check for debris?
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
Actually ended up getting a 2016 Colorado in the other day with 62k on it and owner talked about an intermittent no 1st gear when shifted into drive. No codes. Finally got it to act up. So I snapped some photos for any other Colorado diesel owners that may come across this thread.
 

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Mike L.

Got Sheep?
Staff member
Vendor/Sponsor
Aug 12, 2006
15,686
232
63
Fullerton CA
The new 10 sp will have the same problems. Valve bodies will wear out due to the constant shifting.
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
Yeah don’t know what to expect either with those linear solenoids they are using now In the 10 speed. Monday I‘ll be pulling one off a 10L90