Strange Transmission Operation

[FLYTYER]

Having had no transmission problems this was a surprise today...

On our way to the Mid-Atlantic IRV2 Fall Fest in Lancaster, PA we had to go up and over 7 mountains of which there is a bad 4 mile 9% downgrade on the last mountain. We have traveled this route many many times and never encountered a problem. Today as we always have, at the top we pull into the truck gear change lane, stop and pull the tranny into 2nd gear and then proceed at 20 mph down the mountain. Today at the bottom I shifted the tranny up to 3rd then Drive. It stayed in 3rd !! At the very bottom I slowed down to a stop and restarted in Drive. Everything was OK until 4th gear...that is where it stayed. At the next safe wide shoulder I pulled over, stopped and shut down. I then restarted and drove off with the tranny shifting normally thruough the gears and into OD. We had no further problems. We are now camped here in Lancaster waiting for everyone else to show up.

What is thought to be the cause of this and should I have the tranny checked by a WH service center?

[FLYTYER]

Having had no transmission problems this was a surprise today...

On our way to the Mid-Atlantic IRV2 Fall Fest in Lancaster, PA we had to go up and over 7 mountains of which there is a bad 4 mile 9% downgrade on the last mountain. We have traveled this route many many times and never encountered a problem. Today as we always have, at the top we pull into the truck gear change lane, stop and pull the tranny into 2nd gear and then proceed at 20 mph down the mountain. Today at the bottom I shifted the tranny up to 3rd then Drive. It stayed in 3rd !! At the very bottom I slowed down to a stop and restarted in Drive. Everything was OK until 4th gear...that is where it stayed. At the next safe wide shoulder I pulled over, stopped and shut down. I then restarted and drove off with the tranny shifting normally thruough the gears and into OD. We had no further problems. We are now camped here in Lancaster waiting for everyone else to show up.

What is thought to be the cause of this and should I have the tranny checked by a WH service center?

[Paulin]

We have had similar problems since the MH was new. Many conversation with Allison and WH techs (as recently as last month) have not revealed any cause or solution. No codes have ever been found and Allison can only speculate why this happens. Sure is frustrating.

[Richard 34A]

What has Allison 'speculated' as to what is happening and why? Have they taken any steps to resolve the issue?

[Full-Timers]

I have heard of the Allison's having strange problems related to a computer glitch. Chances are it will never happen again.

[DriVer]

I experienced a loss of power and inability to shift up on my 2001 W20 motorhome. Pulling over and recycling the ignition after a brief period restored proper operation without the anomaly presenting itself for the balance of my ownership. My 2003 has not presented any failure to shift issues.

This could be a once in lifetime event or if it's repeatable then it can be identified and resolved by an Allison dealership pretty quickly.

[dnebout]

This happened to me as well. Would not shift into 4th after climbing the grapevine in 3rd. 2004 32' W20 Allegro

[M&EM]

I have also noticed a very long delay in 4th after exceeding the point where OD shifting would/usually occurs. This was at very light throttle at 60. Eventually shifting onto OD did happen.

These delayed shifts, also in lower gears, seem to mostly occur after long steep uphill pulls. I don't recall a time where the trans didn't finally up shift.

Marty

[JC2]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M&EM:
I have also noticed a very long delay in 4th after exceeding the point where OD shifting would/usually occurs. This was at very light throttle at 60. Eventually shifting onto OD did happen.

These delayed shifts, also in lower gears, seem to mostly occur after long steep uphill pulls. I don't recall a time where the trans didn't finally up shift.

Marty </div></BLOCKQUOTE>
This has also happened to us under basically the same conditions. There have been instances where I have taken my foot off of the accelerator to get it to shift into OD. Other than that, I love that Allison.