A mileage of about 110,000 km, configure the M104 engine and 722.3 automatic transmission Mercedes 300SEL sedan. User report: When the vehicle engine speed reaches 3500r/min , the speed is only 100km / h, continues to accelerate , 4-speed automatic transmission can not ascend ( overdrive ) . In addition , the vehicle reverse gear when dragging phenomenon .
Failure Analysis: The automatic transmission shift control mode is a full hydraulic, hydraulic control valve is the automatic transmission shift control unit , which according to the setting pressure ( reflecting the size of the throttle opening degree ) and the governor pressure ( reflecting transmission output shaft speed ) for shifting . Transmission gear portion by the front portion and the rear planetary gear mechanism the simple planetary gear mechanism composed of the engine power input directly to the planetary gear mechanism sun wheel , single file through the rear planetary gear mechanism to the output shaft carrier . The actuator consists of two clutches (K1 and K2), 3 stoppers (B1, B2, B3) and one -way clutch (F) components.
When the transmission for 4 speed drive , the clutch K1 and K2 simultaneously, the front portion of the front carrier small sun wheel connected as a whole , and the rear sun gear and the ring gear connected to the front as a whole , the transmission ratio is 1 , a direct file that overdrive . When the transmission for reverse gear , the clutch K2 and brake B3 work , the rear sun gear and ring gear connected to the front as a whole , and the front of the carrier being fixed so that the input power from the front wheels via the sun gear and reverse passed to the rear of the ring gear . 4 files preliminary judgment without fault causes include: throttle cable adjustment is not correct, centrifugal speed control valve working poor , poor performance clutch K1 or K2 , the hydraulic control valve working poor .
Check the throttle cable , tightness normal . Governor oil pressure test hole in the bottom of the transmission on the left cooling tubing for hydraulic test results within the standard value , indicating that the governor is normal. Check the vacuum tube , the normal . Unpack the main oil control valve on the plastic cover , the spool clockwise two turns after the test , shift shock becomes apparent , indicating that the main pressure regulator valve work properly. Perform a stall test , the stall speed is 2000r/min, normal . Remove the hydraulic control valve for the disintegration of inspection and found no catching phenomenon . Aligned with 350kPa compressed gas transmission clutch and brake work on the housing hole pressure and could hear the sound implementation of the components of the work , but the sound of a small number of clutch K2 action , indicating that there may be relief . Remove the automatic transmission to the disintegration of the inspection, found the fixed shaft clutch K2 white plastic ring is damaged. Replace the seals, test, fault completely ruled out.
4 are using the clutch and reverse K2, but why can not ascend to the transmission 4-speed , but the reverse can also work , the reason is the clutch K2 is connected in parallel with the one-way clutch F relations . One-way clutch F is not completely replace the clutch K2, so there is reverse hysteresis.
www.carkeydeal.com
没有评论:
发表评论