94 6.5 wont shift into high

[joedcan]

New to the forum and gotta say thank you already. I've already learned so much on here but now I'm stumped. Here's what I got. It's a 1994 c3500 dually 6.5 had all kinda turbo problems but thanks to y'all got that knocked out, haven't turbo mastered yet. New problem is driving for 30 min plus or shutting it down and restarting the tranny won't shift into high gear. No codes unless i push the turbo to hard. Any ideas

 

[ak diesel driver]

is it not shifting into 4th or is the tcc not locking up. also tranny codes won't set the check engine light

 

[joedcan]

I don't know how to check if it is the tcc

 

[ak diesel driver]

count the shifts. If it is the tcc than I'd ohm out the temp sensor in the coolant crossover. PCM needs to see 170* to lock tcc

 

[Brooklyn Tow]

count the shifts. If it is the tcc than I'd ohm out the temp sensor in the coolant crossover. PCM needs to see 170* to lock tcc

Count the shifts in 3rd also.....You should get TCC lockup 43-45 mph

 

[handcannon]

My tranny doesn't lock until 47MPH. Just be aware that there may be some variation between trannys in lockup MPH.

Don

 

[joedcan]

checked the temp sensor had water in the top, also found the wire had been cut and intermittently was touching the motor. changing the sensor and repairing a bunch of cut wires. will let you know.

 

[Brooklyn Tow]

My tranny doesn't lock until 47MPH. Just be aware that there may be some variation between trannys in lockup MPH.

Don

Yea, also my rig is a 3500HD with 19.5's and 4.63 gearz.....probably makes a little difference.

 

[joedcan]

well that seems to have fixed that problem thank you for the help. sorry it took so long had a good ole time changing the oil pan gasket too.