87 4ac auto trans no OD

[yellowhachi]

I have an 87 corolla 2dr w/4ac automatic. Recently the overdrive will not shift in. I've checked the kickdown cable adjustment and is within specs. Changing the fluid did not help either. The local napa store lists a solenoid but does not specify if it's for the OD. Can you guys tell me if this solenoid is for the OD? Any other suggestions to check is greatly appreciated, Thanks.