GMC Safari Transmission

Hello. I Have A 2002 Gmc Safari 4.3 V6 With A 4 Speed 460le Trans W/tow Haul Mode. The Van Has Approx 80k Miles On It. The Trans Has...

Every Few Months, We Drive Our Safari Outside Of The City. And, For The Past 6-9 Months (est), I've Noticed Upshift Failures On Such High-...

The Trans Shift Hard Only In Reverse And 1st Gear And Only When It Cold Out And Will Go Away After The Truck Is Warmed Up, In The Summer It...

At The Same Time I Realized That My Spedometer Was Not Working, I Noticed My Transmission Was Not Shifting. I Can Only Travel About 15 Mph...

After Warm Occasionally Shifts Hard From 1st To 2nd Gear. Serviced Regular, Fluid And Filter Replaced Last Fall When Same Problem Occurred....

I Was Wondering If Any Of You Encountered This Problem Of No Over Drive Shifting And Delay Down Shift During A Stop. Is There Any Controller...