I have a 1985 IROC-Z with an lb9 TPI and 700r4. The transmission is shifting a little early and it seems like it shifts an extra time? I know that's impossible, but that's exactly what it feels like. When I have the shifter in 1 or 2, it doesn't do this, but when i put it in Drive it acts like it's shifting a total of 4 times and when it's in overdrive, a total of 5 times.

It only does this after I have been going down the road for about 2-3 minutes. It cruises about 500 rpm less than It does in overdrive and it actually feels like there's a miss. I'm thinking the Overdrive solenoid located on the transmission is malfunctioning.

Please help me.

 

if the engine feels like it's missing it probably is. the trans is stupid and only locks or unlocks t.c.c. while cruising in fourth(and possibly third in models with a third switch on the valvebody). the rpm drop is normal but the engine missing is probably just that-an engine miss. you probably notice it more because the engine will bog some and causes an additional load to the engine making the miss more noticeable. correct me if i'm wrong.

 

I'm positive it's not an engine miss. The torque converter is choosing to slip for whatever reason. I need to determine if it's a faulty converter or a problem dealing with the tc choosing to lockup/slip. How could I eliminate the tcc lockup solenoid?

 

disconnect the connector on the drivers side of the transmission