Hi,

I have a '91 K2500 Silverado, gasoline, automatic. Sometimes it refuses to leave first gear, regardless of ambient or operating temp. When it happens, I can usually fix it by stopping, shifting into reverse, then back to drive - and it works. Sometimes it takes several tries. It never gives me trouble without me first taking it out of drive, so I can drive for hours without issues. And it's very random, sometimes I can use it for days without it even happening once. I haven't found any patterns or hints of a potential cause.

Another issue is that I have to basically take my foot 100% off the throttle for it to shift after second gear, it sounds like I drive a manual when going down the road.

It was "recently" serviced (6-12 months ago, it's not driven very often) with flushing the transmission, they didn't see anything obvious (metal shavings, state of the oil etc) and the service didn't change the behavior at all. I'm hoping it's something simple, like a sensor, or the shifter, but I know nothing about cars. So, first step, information. Does anyone recognize this or have any tips on how to proceed? As I'm not in the US, replacing the transmission is an expensive ordeal that I'd obviously like to avoid.

Thanks,
Rustration