Lull 6K Service Manual - Manual (Page 553)

Transmission
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K 8-5
9. Check short harness. It connects the solenoids to the transmission
valve connector. It is accessible by removing the transmission valve
assembly cover.
a. Inspect harness and connections from solenoids to the
transmission valve connector.
b. Test continuity between plug ends and valve connector pins.
10. Check transmission pressure. Control pressure should be 230–260 psi
(16–18 bar). See “ZF Transmission Pressure Checks” on page 8-23.
ZF Transmission with DW-3 Shifter
6K-37 (S/N 398–)
6K-42 (S/N 132–)
644B-37 (S/N 881–)
644B-42 (S/N 242–)
8K-42 (S/N 262–)
844C-42 (S/N 784–)
10K-42 (S/N 108–)
10K-54 (S/N 108, 110–)
1044C-42 (S/N 122–)
1044C-54 (S/N 216–) 1. Check for correct fluid and fluid level. Consult Service/Lubrication
Schedule and see the Transmission Oil Selection Chart located in the
Owner/Operator Manual.
2. Check vehicle electrical supply.
a. See “Testing ZF Transmission Electrical System” on page 8-6.
b. Monitor voltage supply for interruption. Check to make sure there is
an uninterrupted 10.5–16.5 volts.
c. Check 7.5 amp fuse.
d. Check ground connections and plug connectors.
3. Isolate pressure/proximity switches. The park brake pressure switch,
the service brake pressure switch in conjunction with the transmission
declutch switch, and the rear oscillation lock proximity switch in
conjunction with the proximity switch relay (R1 relay) can declutch the
transmission.
a. Unplug the park brake pressure switch.
b. Unplug the service brake pressure switch or position the
transmission declutch switch to the “OFF” setting.
c. Remove the proximity switch relay (R1 relay).
4. Check shifter signals. See “DW-3 Shifter System Tests” on page 8-10.
5. Check shifter signals at the transmission solenoid assembly. See“DW-
3 Signals at Transmission Test” on page 8-14.
6. Check transmission valve solenoid integrity. Test resistance of all five
solenoids. Resistance should be 24–40 W.
7. Check long harness (connects shifter to transmission valve connector.
a. Inspect connections.
b. Inspect harness for pinched or severed wires.
8. Check short harness (connects solenoids to transmission valve
connector).
a. Inspect harness and connections from the solenoids to the valve
connector.
b. Test continuity between plug ends and valve connector pins.