So it doesn't up shift to 3rd gear? Or it does after reaching 2000 or 2500rpm. First thing i would is ck the fluid level, then adjust the throttle cable...... for you old timers like me, it was called a TV cable.Also need know the condition of the fluid, red,pink, light brown, dark brown or black. If the fluid is dark, then you may need a transmission seal kit...AKA transmission overhaul.

 

I suspected the fluid is why I changed the fluid and filter. so now the fluid is red, however before it was clear(I've never seen such). seemed to help it but not cure. the shifts pattern happens all at once down to 1st then to 2cnd then to 3rd. doesn't stay long in 1st or 2cnd. because it actually should be in third. I have thought of the throttle cable (same as kickdown linkage right?), however I am leary to adjust being I have never adjusted one.

 

TRANSMISSION THROTTLE VALVE CABLE ADJUSTMENT
The transmission throttle valve is operated by a cam on the valve body throttle lever. The throttle lever is actuated by a cable connected to the engine throttle body lever A retaining clip at the engine-end of the cable is removed to provide for cable adjustment. The retaining clip is then installed back onto the throttle valve cable to lock in the adjustment.

A correctly adjusted throttle valve cable, will cause the throttle lever on the transmission to move simultaneously with the throttle body lever from the idle position. Proper adjustment allows simultaneous movement without causing the transmission throttle lever to move ahead of, or lag behind the throttle body lever.

THROTTLE VALVE CABLE ADJUSTMENT CHECK
Turn ignition key to OFF position.
Remove air cleaner.
Verify that throttle body lever is at curb idle position. Then verify that transmission throttle lever is also at idle (full forward) position.
Slide cable off attachment stud on throttle body lever
Compare position of cable end to attachment stud on throttle body lever:
Cable end and attachment stud should be aligned (or centered on one another) to within 1 mm (0.039 in.) in either direction.
If cable end and attachment stud are misaligned (off center), cable will have to be adjusted as described in following procedure.
Reconnect cable end to attachment stud. Then with aid of a helper, observe movement of transmission throttle lever and lever on throttle body.
If both levers move simultaneously from idle to half-throttle and back to idle position, adjustment is correct.
If transmission throttle lever moves ahead of, or lags behind throttle body lever, cable adjustment will be necessary. Or, if throttle body lever prevents transmission lever from returning to closed position, cable adjustment will be necessary
Throttle Valve Cable Attachment - At Engine
THROTTLE VALVE CABLE ADJUSTMENT PROCEDURE
Turn ignition switch to OFF position and shift into Park.
Remove air cleaner.
Disconnect cable end from attachment stud on throttle body.Carefully slide cable off stud. Do not pull or pry cable off.
Verify that transmission throttle lever is in idle (full forward) position. Then be sure lever on throttle body is at curb idle position.
Insert a small screwdriver under edge of retaining clip and remove retaining clip.
Center cable end on attachment stud to within 1 mm (0.039 in.)
Install retaining clip onto cable housing.
Check cable adjustment. Be sure transmission throttle lever and lever on throttle body move simultaneously and as described in cable adjustment checking procedure.

 

nice!! I'll check the adjustment. Thanks

 

OK. pulled IAT last weekend and it was wet. suspecting plenum gasket (did another thread). Also, could the clutch fan be intermitent? I can turn the blade(engine cold) by hand and on one attempt it will spin 3-4 revs. then try again and doesn't move 3". So think I'm going to do a clutch fan delete( I've actually got 2 T-bird elect. fans sitting around same as mark VII). Which should fix overheating. As for trans shifting could it be possible that a bad plenum gasket is robbing power and the computer is compensating for that causing the downshifts?

 

it definitely sounds like your clutch fan is bad (should turn maybe 1/2 a turn, if more than one definitely bad),

 

Ok I know this is an old thread however, I got a check engine light last weekend. had it scanned at the local parts store and they told me it was a trans shift selinoid (don't know how to spell it) I wrote down the code on my hand but, washed my hands before I realized what I had done. .would this be internal or external on the trans? by the way only time it has ever done it.

 

Internal most likely. But you need the code so scan it again before it's gone in the PCM. There are 2 shift solenoids in the 42-44RE and 46RE. 1-2 and 3-4.