2004 ISUZU NQR with 14’ utility body, electrician’s truck, average weight is 15,000#, GVW 17,000
Transmission 450-43LE, Serial # 3B 1619
Aisin Seiki Co. LTD. Japan
No Fault codes
Engine warm up devise squeaks when cold until throttle position changed. Not sure E brake is working either. Slow coast down hill out of driveway (assume trans hit 2nd) then up hill grade acceleration. Trans needs to get back to 1st to make grade. Holy crap! Trans goes somewhere else, “NOT 1ST”. Grinding, vibration, noisy loud! Let off the gas and manual shift to 1st. All is well when manually shifted.
It also happens when in traffic going slow (not all the time). Won’t go into 1st and makes some noise and grinding and vibration. Sometimes I forget to manual shift to 1st when coming to a stop and it works normally. If I start out on a hill it will do it every time.
Fluid and filter changed twice in 50,000 miles. I did note in the manual that I should change once a year. I have changed my maintenance schedule.
Removed pan and tested 4 solenoids (all with in range), applied approx. 3V to each while blowing on them. The one with black wire seemed to have a little restriction.