Allison 2100 Rough Downshift

[typerr]

Hello

We are the owners of a 2014 Itasca Solei 34T with a 340 Cummins and a Allison 2100 6 speed. Rig has about 18k miles. We pull a 2015 Jeep Grand Cherokee which is right at our 5K toad limit but when I've weighed the rig fully loaded on the CAT scales we were well under our GVRW by 1500# or so. Recently we took a week long trip up and down 395 in California which features a number of long climbs at high elevation. Rig ran fine except for whenever she would downshift to 3rd gear it would sort of buck about three times and then smooth out and continue climbing. Never really slowed down just had that rough 3rd gear downshift. One other time when we came out of a rest stop we were accelerating up hill and she held 3rd and would not shift into 4th for about 10 seconds and then finally shifted. Only did that once. Does it sound like a transmission issue? Thanks

[dbarton291]

Sounds to me like either the transmission was adapting to conditions it sensed and/or the bucking was a result of movement in the driveline/towing system. If there are no warning lights on or resulting transmission diagnostic codes present I would not be concerned at this time.