Bronco L6-300 4.9L VIN Y 1-bbl (1983)
Throttle Valve Cable/Linkage: Customer Interest
A/T - AOD, Harsh Down Shifts
Article No. 83-13-9
TRANSMISSION - AOD - HARSH DOWN SHIFT
FORD 1983 ALL CARS
LINCOLN-MERCURY 1983 ALL CARS
LIGHT TRUCKS 1983 ALL LIGHT TRUCKS
CALIBRATIONS: All with AOD Transmission and 2150 2V carburetor
If the torsion return spring binds on the throttle shaft, and prevents the TV linkage from completely returning to idle position, the result may be harsh
down shifts. An external assist spring can be added to assure positive TV linkage return.
If a vehicle exhibits the above shift concerns, first, determine if it is caused by the lack of return of the TV linkage by the following diagnostic procedure.
1.
Place the transmission in Neutral or Park.
2.
Bring the engine to normal operating temperature.
3.
Remove the air cleaner.
4.
With the engine running and the transmission in a forward gear and the foot service brake pedal applied, accelerate the engine to approximately
onehalf throttle then slowly return the throttle to idle.
5.
While still idling in a forward gear, have another Technician visually check that the TV linkage at the carburetor returned all the way to idle. This
can be determined by observing if there is a gap between the TV lever adjusting screw and the throttle lever pad.
6.
Shut off the engine.
7.
If a gap occurred, determine if it was caused by interference with the TV rod or binding of the grommets. If no interference or binding of the
grommets exists, lack of return of the TV linkage is due to insufficient return force from the torsion spring at the carburetor. Follow the procedure
for installation of a new TV return spring.
NOTE:
A TV lever gap at idle may be caused by a short TV rod. However, the shift concerns would not be harsh 3-4, 4-3 shifts or harsh
engagements, but they would be characterized by early soft shifts and slip/bump during upshifts.
8.
If no gap occurred at the TV lever adjusting screw and the throttle lever pad, the subject shift concerns may be caused by a misadjusted TV rod
that is set too long.
To Install a New TV Lever Return Spring:
1.
Disconnect the transmission TV rod at the carburetor lever.
FIGURE 6
2.
Install the drill. guide fixture (furnished in kit No. E3PZ-9590-A) over the TV lever ball stud (Figure 6).
3.
With a greased #17 (.170) drill bit, (drill guide in position) drill through the lever. Use care as the drill breaks through. Wipe/contain the metal
chips during the drilling. Re-apply grease to the bit as necessary.
4.
Deburr the hole (both sides) and press in the Thompson Nyliner bushing #212-FF furnished with large diameter flange outboard. The bushing
prevents spring tang breakage due to torsional friction.
5.
Unhook the torsional spring where it loops around the TV lever.
6.
Cut the loop (or hook area) of the spring with side cutters to prevent possible interference at wide open throttle. Cover with cloth to contain the
broken piece.
