Palazzo Allison Transmission 2100 MH

[BJMac75]

Took usedunit out on first trip. about 200 miles in we experienced the transmission automatically go from overdrive (6th gear) to 4th gear. The RPM changed as should be expected. This did this numerous times. As we were experiencing ice and snow we pulled over and stayed a rest stop. Next morning was good for another 50 miles. Found a repair shop and they replaced the power supply cable to the the transmissions TCM. Test drove for 20 miles no problem. About 150 miles later got into some rain and acted up again (same conditions but this time only dropped from 6 to 5 gear. Once dried up no issue.

On way home we experienced same problem with the transmission shifting from overdrive (6th gear) to other gears during wet conditions. This is a 2017 Palazoo with only 3500 miles.

Wondering if anyone else has experienced something similar. Thor defers to allison who I am calling tomorrow.

[TurnerFam]

I don't know that we've experienced the 'same' conditions, but I supposed that it's possible that it's doing exactly what it's designed to do in those conditions - but, yes, having Allison come into the equation makes more sense - they'll know what it 'should' be doing - if different....

[BJMac75]

I doubt it is doing what it should do, Jumping from 2100 rpm to 2400 rpm repeatedly over a few seconds is not good for any transmission. In dry conditions it works great only in wet.

[simidrm]

Allison makes and has a really good reputation and is same transmission in my motor home, while mine has never done that I can tell you if it only does that in wet conditions then its a good bet water is getting past the weather pak connector and most likely it would be at the transmission output speed sensor as this tells the engine what rpm the tailshaft is spinning and if water corrupts that signal the transmission computer is reacting to that signal and trying to keep the engine rpm matched to tailshaft speed, they will also downshift based on transmission fluid temp to keep from overheating mine has done this when going through the moutains outside of denver colorado.

[BJMac75]

Issue repaired, rubbed wire on the chasis.

[Campnjoe]

Originally Posted by BJMac75

Issue repaired, rubbed wire on the chasis.

Did you end up taking it somewhere or did you sort it out on your own?

[simidrm]

Originally Posted by BJMac75

Issue repaired, rubbed wire on the chasis.

Typical that happens a lot even with mine the chassis module on mine threw a code for no j1939 communication and that’s what it was, the factory ties the harnesses to tight to the frame and when they flex it rubbed through but in my case it pulled a plug apart

[scfrisco]

Interesting....I can't use the up or down arrows to upshift or downshift....anyone else have this problem....Allison2100 MH trans on a Palazzo 33.2?

[Bob Denman]

Originally Posted by BJMac75

Issue repaired, rubbed wire on the chasis.

I'm glad to see that the problem has been found and fixed!
https://www.thorforums.com/forums/at...1&d=1618511703