2000 Blazer - rough gear transitions

[theranger969]

Hello,
I have a 2000 Chevy Blazer LT(automatic). There is something wrong with it and just wonder if anyone out there might have an idea what might be wrong.

After I am out on the highway doing 55-65mph and exit the highway, my truck starts bucking when entering into the second and third gears. In other words, after I come to a complete stop, then start taking off... the transition from first gear slams into second gear and second gear slams into third gear, but not as hard. It will keep doing this. But if I stop the engine for like a half an hour or so, then start driving again it seems like it reset itself. Could this be a sensor?
Any help or feedback would be appreciated!
THank you

[Cloud Strife]

When was the last time you did service on the transmission? What I mean by this is a fluid/filter change.

[theranger969]

I am pretty strict when it comes to the fluids and filter changes. I have had the filter changed a couple times since this started.

[old_master]

If there is dirt or a burr on a valve, or in its bore, in the valve body, nonexistent, erratic, or harsh shifting can occur. If changing the fluid and filter does not cure the problem, valve body disassembly, inspection and repair will be necessary.

[theranger969]

But would it not happen all the time if it had to deal with the valve? Like I said, it only happens sporadically.... Intersting.

Have you personally seen or dealt with something like this before? Can it get expensive?

I am not too familiar with engine work.... but could it possibly be a sensor or something like that? Just curious for your opinion.

thank you!

[maxwedge]

Originally Posted by theranger969

Hello,
I have a 2000 Chevy Blazer LT(automatic). There is something wrong with it and just wonder if anyone out there might have an idea what might be wrong.

After I am out on the highway doing 55-65mph and exit the highway, my truck starts bucking when entering into the second and third gears. In other words, after I come to a complete stop, then start taking off... the transition from first gear slams into second gear and second gear slams into third gear, but not as hard. It will keep doing this. But if I stop the engine for like a half an hour or so, then start driving again it seems like it reset itself. Could this be a sensor?
Any help or feedback would be appreciated!
THank you

I would have it scanned on a trans function scanner and they will look for a possible bad pcs solenoid,or other trans codes.This will eliminate a lot of guess work.

[old_master]

I have dealt with this exact complaint many times. The harsh shifting is most likely to be noticed only after the transmission is hot. The valve body is aluminum and the valve is steel. Expansion rates are different between the two metals. The valve binds in the bore and causes the harsh shift. You indicated it shifts normally after it cools briefly, that was my main clue in your case. As far as repair costs: yes, it can be expensive. More than likely, the SES light will not come on.