confusing tranny problem

'96 Bonny, normally aspirated. No codes.
Took it out for a Sunday drive, this is what I get...
At 45 mph, holding the throttle steady, I lightly applied the brake. RPM skipped up maybe by 200. After releasing brake tension, the RPM dropped by about 200. I'm thinking "the tcc is working again!" On the highway, at 65 mph, the tach shows me about 3000 RPM. I lightly applied the brake, RPM skipped up by about 200...
then down 200 after brake release. After performing this experiment several times, I confirm that the tcc is engaging, but not overdrive.
Several runs up and down the hiway under different acceleration and inclines, I've determined it is not going into overdrive. However...it may be trying to get overdrive when I "wiggle" the column mounted shift lever from 4th into 3rd. After all my investigation I have to start over. Do you guys have any ideas to what is happening here? Thanks, Ken

Does sound like the TCC is engaging, but you don't have fourth gear.....

Start car in "3" instead of "D"....get it up to 65......are rpms at 3K(make sure the car is at normal operating temp).?.....now shift into "D".....if no change in rpm's, no fourth gear....

Confirmed...Changing gears, 3 to 4 and back...No 4th gear. Is this something Sea Foam can fix, or is this a job for superman? lol

More than likely the trans will have to come out as the o/d clutch hub has failed, common problem on these trans.

Yeah... I hate automatics. Fixing this thing is gonna cost more than the car is worth. Reckon I'll have to figure something out. Thanks for the feedback, guys.

Its not really common of the 4T60E to kill off the 4th Hub splines... It is possible for the clutches to be shot for overdrive...

I would at the least have a trans shop or a good shop scan the car to see if anything is off kilter before you doom the trans...