Filter
Top Products
7 - 21
7.1 HYDRO TRANSMISSION TROUBLESHOOTING
The following troubleshooting chart is to be used to
isolate hydro transmission problems and give possible
causes and corrective action responses.
The troubleshooting key is generic and can be used for
several types of transmissions. Use only those
possible causes and corrective actions that apply to the
unit.
SECTION 7 - DRIVE TRAIN
TROUBLE POSSIBLE CAUSES
(Refer to Key Below)
CORRECTIVE ACTION
Axles Will Not Turn 1, 7, 8, 12, 16, 18, 28, 32, 38, 42 repair or replace
Difficult Starting 1, 6, 7, 8, 12, 16, 25, 26, 28, 38, 42 repair or replace
Erratic Running 1, 4, 6, 7, 8, 12, 18, 25, 26, 28, 42, 55 repair or replace
Jerky When Starting 1, 4, 7, 8, 12, 18, 28, 38
Jumps Out of Gear N/A repair or replace
Knocking 4, 8, 12, 18, 28, 37, 42 repair or replace
Loss of Power or System 4, 12, 18, 28, 37, 42
Noisy 4, 12, 18, 26, 28, 32, 37, 42 repair or replace
Oil Leakage 4, 22, 51, 16 repair or replace
Operates Hot 4, 16, 28, 32, 35, 42
Operates in One Direction Only 1, 8, 12, 30, 46
Pump Failure 4, 12, 37 repair or replace
Speed Loss Under Load 1, 6, 11, 28, 37, 51 repair or replace
Speed Loss Under Load 1, 4, 7, 12, 18, 28, 26 repair or replace
Will Not Drive 1, 7, 8, 18, 28, 37, 38, 48
Will Not Shift repair or replace
TROUBLESHOOTING KEY
1 Inspect control linkage 22 Inspect hoses and lines for wear 43 Burrs on gearing
2 Inspect acceleration valves 23 Inspect implement relief valve 44 Gears improperly installed
3 Inspect charge check valves 24 Inspect charge pump 47 Shifting washer in backwards
4 Incorrect grade of lubricating oil 25 Bad transmission pump 48 Shifter/Brake shaft keyways damaged
5 Low cranking speed 26 Overheating 49 Unit clutch not disengaging
6 Controls not in correct operation
position
27 Cold running 50 Shifter stop assembled backwards
7 Belts are missing, to tight, loose or
glazed
28 Bad transmission motor 51 Improper fit of case to cover
8 Overload of vehicle 29 Check system pressure 52 Dowel pins not installed
9 Replacement parts damaged 30 Shift rod grooves worn 53 Differential bevel gears broken
10 Replacement parts improperly
installed
31 Reverse chain broken 54 Spring in shifter weak or broken
11 Improperly torqued attaching screws 32 Damaged cooling fan 55 Worn or stripped gear teeth
12 Air in hydraulic system 33 Inspect auxiliary relief valve
13 Broken shifter stop 34 Inspect cooling fan
14 Inspect charge check valves 35 Inspect transmission cooling fins
15 Inspect acceleration valves 36 Worn or damaged bearings
16 Check oil level-gear box sump or
reservoir
37 Metallic pieces or foreign objects in unit
17 Inspect heat exchanger 38 Inspect for loosely mounted
components
18 Inspect by-pass valve 39 Steering column loose or binding
19 Inspect charge pressure 40 Pressure relief valve sticking open
20 Inspect inlet filter 41 Pressure relief sticking closed
21 Inspect charge relief valve 42 Broken relief valve spring