right now it goes into overdrive at about 55mph light throttle with TCC lockup. Will adjusting my kickdown make it go in sooner. Seems like everyone else'* goes in at about 48-50mph. I'm gonna check this out in the morning and see if it makes a difference.

the TCC lockup depends on the Engine load, and TPS sensor, with a few inputs

well i think it is normal mine goes in to 4th at 48 and then tcc lockesup at 55

It'* not off by much. Like 1993 SLE mentioned, there are varying inputs and factors that will make it shift and lock.

Engine temp
Load
Hills
Throttle
Tons of stuff

Just my $0.02, but just be glad it even goes into overdrive, regardless of the speed it engages at. After a few hundred dollars, mine finally will engage and hold full lockup. And that'* AFTER spending $375 on a used transmission.

Just my $0.02, but just be glad it even goes into overdrive, regardless of the speed it engages at. After a few hundred dollars, mine finally will engage and hold full lockup. And that'* AFTER spending $375 on a used transmission.

my ssesc goes into lockup at 48mph every time, unless im mergeing on the expressway or such.