transmision problems 88 400 turbo

I have an 88 sub with 454 and 400 turbo trans. sometimes when it hasnt been run for a couple days transmision doesnt engage, but if you let it warm up for about 10 minutes it will go into gear just fine. i think my torque converter may be bad. any thoughts ?

Could also be a bad pump. Need to check line pressure to be sure.

//2000CAYukon

I have an 88 sub with 454 and 400 turbo trans. sometimes when it hasnt been run for a couple days transmision doesnt engage, but if you let it warm up for about 10 minutes it will go into gear just fine. i think my torque converter may be bad. any thoughts ?

Have you checked the fluid level hot engine running in park.

How is the fluid condition and filter?
Ever been serviced?
What is the mileage and service and repair history?
Pan drop and new filter fixes a lot of 400 problems.
When opan is off also see what is in the bottom of pan.
Post back info and what you find.