Dura max won’t downshift July 15, 2018, 10:47:33 am Yahoo Message Number: 16771My 2005 C5500 Duramax won't downshift when pressing the pedal all the way, shifts fine for all other conditions. Any body else have this happen? Quote Selected
Re: [SuperCrvgroup] Dura max won’t downshift Reply #1 – July 15, 2018, 02:59:24 pm Yahoo Message Number: 16772I've noticed the same. It wasn't the case originally after I bought the rig about 18 months ago.However, this problem only happens at speeds above 40 mph. It will downshift on a hill at slower speeds. The problem is most apparent on the highway on mountain passes where I'd rather be in a lower gear doing 45 mph rather than dropping below 40 before the downshift happens. But flooring it won't make that happen so I manually do it with the shifter on the steering column.I was thinking this was a vacuum hose problem and was planning on talking to my mechanic next time I get her serviced. Most of the C5500s he works on are Top kicks with a lot more miles than most RVs so I am hopeful it's a common fix. He did tell me previously that the Allison is "bulletproof" and he never sees any issues before 300K... Quote Selected
Re: [SuperCrvgroup] Dura max won’t downshift Reply #2 – July 18, 2018, 12:04:05 pm Yahoo Message Number: 16782Sometimes it simply takes a minute to pull over and turn everything off and reset. It's really the first thing to do when something unusual concerning driveability happens. Quote Selected
Re: [SuperCrvgroup] Dura max won’t downshift Reply #3 – July 18, 2018, 02:29:41 pm Yahoo Message Number: 16784It went back to normal the next day. Hoping it doesn't re-occur.... Thanks for replying. Quote Selected