When a Dynaflow transmission does not operate properly it is advisable to first check the (manual control) 1953 Buick Dynaflow linkage adjustment.
Before making any checks or adjustments on manual control linkage make certain that transmission is thoroughly warmed up and that oil is at proper level.
- Park car on ramp or steep grade with control lever in Parking (P) position to determine whether parking lock holds securely. Then let car roll with control lever in Neutral (N) position and listen for a clicking or ratchet noise which would indicate that parking lock pawl is contacting the parking lock ratchet wheel.
- If parking lock fails to hold, or ratchet noise exists in Neutral, adjust shift rod as described in Steps 3, 4, 5; otherwise proceed to Step 6.
- Place control lever in Parking (P) position and disconnect the lower shift rod from shift idler lever by removing clevis pin and spring washer. Pull forward on shift rod and move car slightly to make sure that locking pawl is fully engaged in ratchet wheel. Do not jerk on rod as this may spring linkage in rear bearing retainer.
- Check movement at lower end of transmission shift lever by pushing forward against spring pressure until a definite stop is felt. The spring travel or movement of lower end of lever should be 1/8″ to 3/16″ beyond the Parking (P) position. If spring travel is not within these limits the control valve operating rod in transmission must be adjusted.
- When spring travel is correct pull shift rod forward until stop is felt then adjust shift rod clevis until clevis pin will just enter hole in shift idler lever, with control detent firmly engaged in Parking (P) position. Lengthen shift rod by unscrewing clevis 3 complete turns, then temporarily connect rod to idler lever with clevis pin.
- With transmission warmed up and engine idling at approximately 600 RPM, slowly move control lever from Neutral (N) to Drive (D) position. The clutch should engage, as indicated by an immediate decrease in engine speed when the tip of dial pointer is midway between “N” and “D” on speed ratio dial.
- Slowly move control lever from Drive (D) position to Neutral (N) position. Clutch should disengage, as indicated by an immediate increase in engine speed, .when tip of speed ratio pointer is midway between “D” and “N” on speed ratio dial.
- If points of clutch engagement and disengagement are not as specified adjust shift rod clevis (Steps 3, 4, 5) to obtain required setting, being careful not to change clevis so much that parking lock fails to hold or parking lock pawl contacts ratchet wheel in Neutral (N).
- Check operation in Low (L) and Reverse (R). Low and Reverse should be obtained when detents are engaged and the shift points should occur when tip of dial pointer is midway between “L” and “R” on speed ratio dial. If these conditions are not correct, the transmission shift lever may be bent.
- After adjustments are completed, tighten clevis lock nut securely and permanently install clevis pin with spring washer located between shift idler lever and clevis; install cotter pin.