1996 LT1 Automatic will not shift into high gear

[jad9943]

Can anyone give me a starting point as to why my 96 LT1 automatic will not shift into high gear. I have changed both solonoids in the transmission. I have googled this problem. No one seems to have an answer. It will sometimes shift into high but most times not.

 

[trhao]

Have you verified that the torque converter is not locking up? I ask because sometimes people assume it's not going into 4th when it is in 4th but not locking up. When it locks, it's like an upshift.

 

[boomdriver]

Have you verified that the torque converter is not locking up? I ask because sometimes people assume it's not going into 4th when it is in 4th but not locking up. When it locks, it's like an upshift.

I was wondering about the TCC solenoid as well.

 

[Hib Halverson]

"Trhao" and "Boomdriver" are right.

Make sure it's really 4th gear and not the TCC.

 

[jad9943]

How do I determine it is TCC and not torq converter?

 

[Hib Halverson]

Well...if you have a good feel for the car you can road test. If the TCC is working you should feel a "fifth shift" when the TCC locks up. Also, you can try manually shifting from D to OD and see if you feel a shift. Once you do that, you should feel (and see on the tach) when the TCC locks.

Otherwise you need a scan tester which indicates which gear the trans is in and if the TCC is enabled.

A trans shop ought to be able to diagnose it for you.