Had some work done at the dealer where they had to remove the right rear wheel and replace an exterior plate that had some connections on it. Ever since that time...the tractor automatically shifts down to a lower gear...to turtle from rabbit...under every circumstance. If hold the shifting lever for the 2 different speeds...I can keep it in the faster speed but the minute I let it go...it down shifts. The dealer seems to have no idea what the problem is...Anybody out there experience the same issue? Thanks