Chevrolet Repair: auto transmission, chevy store, long periods of time

Question
Hi,I have a1985 454 Chevy with auto tranny.it is in a Motorhome.I drove it today and it didn't shift till I hit almost 35mph.I feel this doesn't seem right.any ideas,thanks alot

Answer
HI DAVE,YOU ARE CORRECT THIS IS NOT RIGHT. I WILL ASSUME YOU HAVE CHECKED THE TRANNY OIL RUNNING AND WARMED UP ON LEVEL GROUND..OK GOOD..MAKE SURE THE OIL LEVEL IS FULL OF COURSE. THIS IS A TRICKY QUESTION BECAUSE THIS YEAR OR ABOUT THIS YEAR GM STARTED CHANGING THE WAY TRANSMISSIONS SHIFTED.FIRST THING COMES TO MIND IS DOES THE KICK DOWN LINKAGE WORK OK ??[IF YOU ARE IN HIGH GEAR AND NAIL THE THROTTLE DOES IT KICK DOWN TO THE NEXT GEAR TO PASS]??  IF NOT THIS COULD CAUSE THIS PROBLEM,KICK DOWN LIKNAGE IS STICKING. SOME ARE CABLE DRIVEN AND SOME ARE ELECTRIC. DOES YOUR SPEEDO WORK ??? IF NOT,, THIS IS MORE THEN LIKELY THE PROBLEM IF IT HAS A ELECTRONIC DRIVEN SPEDO PICK UP..IF IT DOES NOT HAVE A ELECTRIC ASSISTED VALVE BODY. 2 THINGS COME TO MIND..THE ACCUMULATOR IS STICKING[ON THE SIDE OF THE TRANSMISSION]OR A SHIFT VALVE IN THE VALVE BODY IS STICKING..IF THIS HAS A ELECTRONIC VALVE BODY. THEN A SHIFT SOLENOID COULD BE BAD. DOES THIS SIT FOR LONG PERIODS OF TIME ??? IF SO I WOULD SUGGEST DRAINING THE TRANS OIL AND INSTALLING A NEW FILTER AND FRESH OIL AND SEE IF THIS HELPS..SOMETIMES WHEN THESE THINGS SIT FOR A WHILE THE OIL GETS THICK AND THE VALVE BODY GUMS UP CAUSING VALVES TO STICK. AGAIN, THIS IS MORE COMMON ON THE OLDER STYLE TRANNYS. LESS COMMON ON ELECTRONC ASSISTED VALVE BODY'S, BUT I HAVE SEEN THIS HAPPEN AS WELL. I KNOW I GAVE YOU ALOT OF THINGS TO FIND OUT ABOUT YOUR TRANMISSION AND THE EASIEST WAY TO FIND OUT ABOUT IT IS CALL YOUR LOCAL CHEVY STORE AND GIVE THEM YOUR VEHICLE ID# AND THEY WILL BE ABLE TO ANSWER THESE QUESTIONS ABOUT YOUR TRANNY..I HOPE THIS HELPS YOU OUT,GOOD LUCK,GET BACK TO ME IF YOU NEED MORE INFO,,TOM...