Problem with 1/2 shift at WOT

[billsgn]

What could be the possible causes for the trans to not shift from 1st to 2nd at WOT unless you let off? 1-2 shifts are fine with normal (not WOT) throttle.

Thanks in advance....
Bill

 

[billsgn]

Anyone have any idea what could cause this?

 

[Otto J]

Is it holding tight if you get it into second gear and throttle it?

 

[billsgn]

Is it holding tight if you get it into second gear and throttle it?

Not sure as it is on a car I was trying to buy....thanks for responding tho.