I have a 95 GCL which will start up in a middle gear and not shift to a lower or O/D. Once its warm, it will usually engage into first gear and follow the shifting patterns normally. Does anyone know what could be causing this? (i had the trans. fluid changed a few days ago, but the problem started a month before that). Please help with any ideas

just a guess , but i had a similar problem with my 94 gcl,trans , turned out to be the governer solinoid and transducer in the trans ,under the filter. the mech that did the overhaul used a steel washer and ground them out , needs to be a non magnetic washer in a electronic trans , fairly expensive, parts about $300.00, + labor , mine was starting out in 2 nd gear , but worked in manual shifting