Hard shift 2010 Chevy 1500 extended cab

I have a 2010 Chevy 1500 extended cab. For a few years it was a daily driver. It has 54000 miles. For the last 1.5 years I have been driving a company vehicle so my truck sits a lot and usually only gets driven once a week when I’m off running errands and such. Recently if I drive it just around town a few miles here and there, everything is fine. But if I drive it to a farther location say 20-30 minutes away the truck will start to shift extremely hard into second gear from first to second. The first time it happend I though I got rear ended by another car only to look around and no one was behind me. I wouldnt think the trans. would be going out at 54000 miles. Any. Thoughts?

It is quite likely that the computer is picking up a problem and cranking the line pressures in the transmission up to max. Believe it or not it’s trying to “save” your transmission from any further damage. If you listen closely you might hear a somewhat high-pitched whining noise, especially when you’re just starting off from a stop.

Whether your check engine light is on or not (is it?) there are probably some error codes that end up getting stored in the computer. Since this is a GM it is also likely that you will need to have it scanned by someone with a Tech II scanner - normal, generic code readers probably won’t get these codes.

It’s kind of important that it gets scanned WHEN it is doing this. So a shop will have to drive it long enough to get it to act up or you’ll need to get it to a shop to scan it when you’ve gotten it to act up.

Have you at least checked the transmission fluid, btw?

The check engine light has not come on and yes I checked the fluid. The level is where it should be. I change my engine oil regularly. Should I have the trans fluid changed and new filter yet?

A lot of professional transmission experts recommend fluid/filter service every 30K miles.

Since you’re thinking about it - and having this problem - then I would find your best locally owned and operated transmission specialty shop. Do not go to transmission chain shops and don’t take it to a general mechanic unless you know s/he is very specifically a transmission expert. Take it to the local shop, explain your problem and see what they recommend. I suspect there is a problem that will not be solved by a filter/fluid service, but they may do it as part of inspection / diagnosis because what they find in the pan will tell them a lot. But they will really need the error codes to find out what is up. It could be something really simple (or not).

Ok I’m on vacation next week so I will be taking it in. Thank you for the insight! I appreciate the help!

Sometimes play in the driveline can cause a symptom like this. Like a bad u-joint or similar. Do you notice any unusual noises when parallel parking, where you have to pull forward and back up repeatedly? In any event it wouldn’t hurt to ask your mechanic to do a quick visual inspection of the driveline, twist here and there to test for any unusual play.