wont shift from N

paultracy3 · 12-03-2010, 03:28 AM

have a 99 newell with a 6 speed allison drove it 300 miles the other day to co camping in the sand dunes . parked for 3 days , fired the bus up to leave and it would not shift from neutral into drive or reverse . messed around for 6 hours checking for codes , unpluging the allison brain , check this sensor that sensor . nothing . got a guy to pull me with a 4x4 to get the bus closer to the main road , i had the bus engine running so i had power steering , we were rolling about 2-3 mph as he pulled me and i hit the drive key on the pad and it went in gear . i said holly crap it fixed itself , i went back to neutral and again it would not go back into gear . pulled the coach again and it went into gear , then i checked if it would go in reverse without going to neutral first and it did . i went for it and drove home 300 miles no problem with the tranny but never put it in neutral . got the bus back in my storage , put it in neutral again and it would not shift into gear again ... any thoughts on this please help

Summersgal · 12-03-2010, 10:28 AM

paultracy3,

I once sat in my driveway for an hour trying to get mine to shift, it would not go in forward or reverse. I found the fast idle switch was in the up position.

Jeff

paultracy3 · 12-03-2010, 02:25 PM

fast idle was not in the up position . in fact i flipped it on and off multiple times to see if the switch was the problem

prairieschooner · 12-03-2010, 02:49 PM

Since I don't have that switch on our '82 I am just suggesting here. If the High Idle Switch can override the Shifting you may consider proving the Switch with a Ohm Meter, if it is OK and Energizes a Relay, check the Relay.
just a thought

afrench45 · 12-03-2010, 05:12 PM

When I had my Prevost, I had this problem. I had to call out Allison because I didnt know what else to do. They unplug all those wires (I'm guessing thats the brain) and then it'd work fine. I had to do this quite often.
Goodluck fixin it! I'm curious to know what the problem is.
Andrew

Ron Skeen · 12-03-2010, 06:09 PM

What RPM is the engine turning when you are trying to put in gear? Mine will not shift at anything over 6-700 RPM. You can adjust the engine idle with the wheel on the board at passenger seat. Idle speed sometime varies under different temp circumstances. Call allison hot line for further info. Have a great Day!

jwe648 · 12-03-2010, 09:53 PM

You maynt to take a look at the tranny connections.. Dirty or bad connections/grounds will confuse it's brains...

HoosierDaddy · 12-03-2010, 10:31 PM

WILD GUESS....If the RPM's were in spec I'm wondering if the RPM sensor was sending an artificially high signal compared to vehicle speed thus not allowing a shift command to be performed with the switch. It seems to me that the 'puter would compare the engine speed with vehicle speed before preforming any command. Once it sensed speed (while being towed) it obeyed the command from the switch.
I too will be very curious to know what you find out.

paultracy3 · 12-04-2010, 03:15 AM

had a guy out from allison today and he plugged into a port with his scanner , no codes , no bad sensors , he was scratching his head . said he will talk with some tranny experts over the weekend

paultracy3 · 12-04-2010, 02:41 PM

Quote:

Originally Posted by HoosierDaddy

WILD GUESS....If the RPM's were in spec I'm wondering if the RPM sensor was sending an artificially high signal compared to vehicle speed thus not allowing a shift command to be performed with the switch. It seems to me that the 'puter would compare the engine speed with vehicle speed before preforming any command. Once it sensed speed (while being towed) it obeyed the command from the switch.
I too will be very curious to know what you find out.

engine rpm on the tack is between 5-600 . on the computer scanner it read 560 rpm

prairieschooner · 12-04-2010, 02:43 PM

I love it, Mechanic travels to troubleshoot the problem. He plugs in a Scanner and sees no Trouble Codes so he is now Dumbfounded! but I am sure that the clock is still running!
I had a very similar problem with a '06 F250 6.0 Diesel. The truck wouldn't run properly at Altitude (we live at 6,500'). First thing that the Service Manager at the local dealership asked was "how often are you at that altitude?" I simply stated every day, I live there. He then asked if there were any "Check Engine Lights" when I answered no, he then stated "How do you expect me to repair it then".
I am only reporting a previous experience to let you know that I understand any frustrations that you have. You may consider using an independent mechanic. With Yachts these guys are usually much more of a "hands on" guy and usually more experienced.
Good Luck!

folivier · 12-04-2010, 03:48 PM

"How do you expect me to repair it then"

Love it! Where are all of the "shade-tree" mechanics? I've gotten where I won't buy a new car, but try and find one of the certified ones with a warranty. And I won't buy top-line models either. Too much stuff to break and not every component has a check engine light.

Wally Arntzen · 12-04-2010, 07:47 PM

On my 88 I had a similar problem in Arizona a couple of years ago. I don't know if the If 99's have air oporated shifting on the transmissions or electronic.
My is air operated and there is an air shift pistion on the passenger side of the transmission that moves forward and backward depending what shift number you put it in and that will move as you change it at your shift handle or switch.
That piston got dry on mine and would not move. I was informed by my friend who is a bus mechanic wizard to get under and squirt it with WD40 or another loosening lubricant and it released it immeadiatly.
If you have the air operated switch make sure that you have the coach brake on when you go under and do this. Better yet turn off the engine and do it because you can move the piston back and forth without it running.

paultracy3 · 12-04-2010, 08:38 PM

Quote:

Originally Posted by Wally Arntzen

On my 88 I had a similar problem in Arizona a couple of years ago. I don't know if the If 99's have air oporated shifting on the transmissions or electronic.
My is air operated and there is an air shift pistion on the passenger side of the transmission that moves forward and backward depending what shift number you put it in and that will move as you change it at your shift handle or switch.
That piston got dry on mine and would not move. I was informed by my friend who is a bus mechanic wizard to get under and squirt it with WD40 or another loosening lubricant and it released it immeadiatly.
If you have the air operated switch make sure that you have the coach brake on when you go under and do this. Better yet turn off the engine and do it because you can move the piston back and forth without it running.

its electric. trans ecu is a allison wtec 2 b500 model

Mikeh · 12-04-2010, 11:20 PM

Does your coach have a slide?

prairieschooner · 12-05-2010, 01:36 AM

that makes sense, if the slide didn't trigger that it was in the coach wouldn't allow itself to go into gear.

Mikeh · 12-05-2010, 02:31 AM

Now ya talkin.

paultracy3 · 12-05-2010, 04:39 AM

Quote:

Originally Posted by prairieschooner

that makes sense, if the slide didn't trigger that it was in the coach wouldn't allow itself to go into gear.

nope tried it ,

rheavn · 12-05-2010, 12:27 PM

The only other thing that I know of that keeps me from putting the coach in gear is if I don't disengage the parking brake. You are disengaging the parking brake obviously as you can pull the coach, but I question whether the sensor is recognizing it. Once you slowly move the coach the sensor then recognizes the parking brake is off and allows you to put the trans in gear. Or when you disengage your parking brake it is hanging up slightly until you move the coach and it completely disengages.

Mikeh · 12-05-2010, 02:47 PM

Paul
Do you have a toggle switch underneath the left console to disable the slide sensor? I don't know about yours but mine has one. This allows you to move with the slides out in case you need to creep forward to level the coach. Mike