Hi Folks,

1994 Barth Regency Diesel here.... Cummins with Allison 5 speed.

Today, we go up to take her out for a nice Sunday outing.

Let her warm up nice and slow.

Press D for Drive and nothing happens. It will not go into Drive.

Press R for reverse and it shifts into Reverse just fin.

Try doing the same with the MODE switch pressed on and the same results.

Any ideas?

I did have her serviced just last week... lube, oil change, gennie service, etc.

Any suggestions are greatly appreciated.

Thanks very much.

John

Hi John. I hope you have already discovered what the problem was, but I can tell you the electronic transmission will not change gears if the air pressure is not built up sufficiently (around 100). For me, there were two potential problems. If the switch on the hydrolic jack is turned on to let the air out, you will lose all your air pressure. Secondly, there are two valves sticking out from under the passenger side in front of the front tires that you drain air (and any condensation) out of. If either one is broken or cracked, you will lose air pressure. Make sure you air pressure is in the 100 range or better, and shifting should work fine.

I won't begin to guess what might be causing this and I hope the experts will weigh in here. I don't think air pressure is the issue though. On my Stagecoach, it won't shift into any gear if the pressure has not built up to the required pressure. I have a 4 speed Allison but I don't think it matters since this is a safety bypass on anything with air brakes. If the air pressure is too low, I'd say there is a secondary problem if it will still shift into reverse but, I don't think that is the case here.

I'm curious if any work was done on the transmission before the trip that might have caused this. You might get lucky and be able to correct the problem yourself after crawling underneath and taking a look. This could be internal (trans), external (shifter) or even electrical. You can always try shifting it into drive manually from underneath (not recommended without blocking the tires and chaining your coach to Pikes Peak while your co-pilot keeps the service brakes on). I had to do this when the shifter literally fell off the transmission. I was lucky, it happened in the storage lot, not on the road in the middle of nowhere and I did not have a co-pilot or chains. Keep in mind, if you turn off the motor with the transmission in gear, the engine will not start again without putting the transmission in neutral. If the gear selector is not responding for drive but only for reverse, it might not take it out of drive either. That would require manually shifting it into neutral from underneath.