a. Fluid Temperature Gauge
1. A fluid temperature gauge may be installed on the equipment instrument panel to indicate converter-out (to cooler) fluid temperature. For models with retarder (Figure 3–2), the gauge sending unit is installed in a tap at the top of the retarder control valve assembly. For mod-CAUTION:
To avoid transmission housing damage and fluid leakage, refer to Paragraph 4–12c prior to remov-ing or installremov-ing temperature and pressure taps.
els without retarder (Figure 3–5), the gauge sending unit is installed in a tap at the left side of the converter housing. The gauge is cali-brated from 150–330˚F (65–165˚C). The nor-mal operating temperature range of the trans-mission is 180–200˚F (82–93˚C). The safe operating range of 150–275˚F (65–135˚C) is marked by a green segment on the gauge. A red segment denotes the overheat range 275–330˚F (135–165˚C). For intermittent retarder oper-ation only, the converter-out fluid temperature may exceed 275˚F (135˚C), but under no condi-tion is the converter-out fluid temperature to ex-ceed 330˚F (165˚C).
2. If the maximum converter-out fluid tempera-ture is reached, stop the vehicle and shift the transmission into N (Neutral). Operate the en-gine at 1500 rpm to reduce the transmission fluid temperature. If the transmission fluid does not cool in approximately 30 seconds, or if it continues to overheat after operation is continued, stop the engine and locate and cor-rect the source of the overheat condition.
b. Checking, Adjusting Main Pressure
1. A pressure gauge may be installed in the instru-ment panel to indicate hydraulic pressure. The gauge is calibrated from 50–300 psi (345–2067 kPa). The 50–140 psi (345–965 kPa) segment is red, the 140–230 psi (965–1585 kPa) segment is green, and the 230–300 psi (1585–2067 kPa) segment is red.
2. Main pressure can be checked by the gauge on the instrument panel (if so equipped) or by con-necting a gauge to the tap on the front side of the main-pressure regulator body (Figure 3–4).
Models with a variable capacity torque converter have the main-pressure tap on the stator control valve body (Figure 3–6). Main pressure must be 170–185 psi (1172–1275 kPa) in all ranges with the engine running at 1500 rpm, converter-out temperature 200–225˚F (93–107˚C), and the out-put stalled.
3. The gauge continuously registers the pressure in the main-pressure circuit and the applied clutches.
PREVENTIVE MAINTENANCE
4. If the operating pressures do not fall within safe operating limits, main pressure requires adjust-ment. Raise or lower main pressure by adding or removing shims at the booster signal plug end of the main-pressure regulator valve spring. To add or remove shims, remove main-pressure regula-tor valve plug 13 (Foldout 13, 14,A, or 14,B), gasket 12, and booster plug 11. Shims 10 are lo-cated in the bore of the booster plug. Add or re-move shims to obtain the proper main-pressure readings. Shims are available in thicknesses of 0.0289 inch and 0.0528 inch (0.734 mm and 1.341 mm).
c. Checking Lubrication Pressure. The lubrication pressure may be checked by connecting a pressure gauge into the check point on the left side of the converter
housing (Figure 3–5). The lubrication pressure must be approximately 20 psi (138 kPa) when the transmission is in first range, with the output stalled, the transmission at a normal operating temperature of 180–200˚F (82–
93˚C), and the engine running at 1000 rpm.
d. Adjusting Lubrication Pressure (Models Without Retarder)
1. The purpose of setting lubrication pressure at 30 psi (207 kPa) maximum at full throttle with the output stalled is to limit converter-out pres-sure to 65 psi (448 kPa) maximum. This as-sures adequate lockup clutch capacity, since converter-out pressure opposes lockup clutch engagement. Converter-out pressure is a func-tion of lubricafunc-tion pressure and cooler circuit restrictions. If converter-out pressure exceeds
Figure 3–4. Hydraulic System Check Points (Straight-Through, Electric-Shift Models, Models With Non-Electric Lockup, and Models Without Trim Boost)
MAIN-PRESSURE TAP SPLITTER-HIGH
PRESSURE TAP BREATHER
PITOT PRESSURE TAP LOCKUP PRESSURE TAP HIGH-EFFICIENCY
FILTERS ELECTRONIC CONTROL VALVE BODY ASSEMBLY
HIGH-RANGE PRESSURE TAP
FILTER DRAIN PLUG (2)
SPLITTER-LOW PRESSURE TAP STRAINER
DRAIN PLUG LOW-RANGE
PRESSURE TAP
REVERSE PRESSURE TAP
INTERMEDIATE-RANGE PRESSURE TAP
H00684.01
5600, 5800, 5900, 6000, 6600 SERIES TRANSMISSIONS
Figure 3–5. Hydraulic System Check Points (Models Without Retarder) MAIN PRESSURE TAP
LUBRICATION PRESSURE TAP
H03574.01
CONVERTER FLUID TEMPERATURE AND PRESSURE TAP
CONVERTER-OUT CONVERTER-IN
65 psi (448 kPa) after the lubrication valve has been adjusted, and the cooler is not restricted, larger lines are required in the cooler circuit.
2. Lubrication pressure must not be less than 20 psi (138 kPa) in all drive ranges and neutral at 1500 rpm with the output stalled. It must not exceed 30 psi (207 kPa) in neutral, at full throttle with the output stalled. If the lubrication pressure CAUTION:
Do not use more than ten shims to adjust the lu-brication pressure. If more than ten shims are re-quired, replace the spring or check for additional causes of pressure loss.
needs to be adjusted, add or subtract shims 68 (Foldout 11) between lubrication regulator valve 67 and spring 69. Each added shim will increase the pressure approximately 2 psi (14 kPa).
3. After adjusting the lubrication pressure, check the converter-out pressure at full throttle, and at normal operating output speed range.
e. Checking Converter-out Pressure. Converter-out pressure may be checked at the point provided for at-taching the temperature gauge sending unit (Figure 3–2 or 3–5). With the transmission at a normal operating temperature of 180–200˚F (82–93˚C), converter-out pressure at full throttle stall is 30–65 psi (207–448 kPa).
Refer to Paragraph 3–16 for stall test procedures.
PREVENTIVE MAINTENANCE
f. Checking Fluid Velocity Governor (Pitot) Pres-sure (Models With Non-Electric Lockup)
1. Install a pressure gauge at the lower plug on the lockup valve body (Figure 3–4) or the up-per plug on the right side of the retarder hous-ing. Governor (pitot) pressure depends upon the rotation of the splitter-low clutch drum. No reading can be taken unless the equipment is operating. In neutral, with the engine running at 1000 rpm, the reading will be proportional to the speed of the turbine output shaft and will vary from 0 to approximately 30 psi (0 to ap-proximately 200 kPa).
2. Readings in each range will be proportional to the speed of the equipment in that range. There will be a momentary drop in governor pressure as shifts are made from one range to another.
3. When upshifting, the pressure will quickly re-turn after the shift is made but the pressure will be lower than before shifting. It will climb as equipment speed increases. When downshift-ing, the pressure will return and be higher than before shifting. It will fall as equipment speed decreases. Under differing operating condi-tions, pitot pressure will vary from 0–120 psi (0–827 kPa).
Figure 3–6. Variable-Stator Control Valve Body Assembly — Showing Pressure Check Points
VALVE ADAPTER VARIABLE STATOR CONTROL
PRESSURE TAP VALVE PLUG ADAPTER
STATOR CONTROL VALVE BODY ASSEMBLY MAIN PRESSURE TAP
H00712
g. Checking Stator Control Pressure (Models With Variable-Capacity Torque Converter) 1. The stator control pressure is taken at the top
of the stator control valve (Figure 3–6). With the transmission in neutral, at a normal oper-ating temperature of 180–200˚F (82–93˚C), and engine speed at 1500 rpm, the pressure must read 0–20 psi (0–138 kPa). Actuate the OEM-supplied stator shift control mecha-nism. The pressure gauge must read 150–170 psi (965–1172 kPa). When the stator control is released, fluid pressure at the gauge must drop to 0–20 psi (0–138 kPa).
2. If main pressure readings are satisfactory (Paragraph 3–11b), but stator control pressure fails to meet the 150–170 psi (1034–1172 kPa) range, replace stator control valve spring 28 (Foldout 13).
h. Checking Range and Splitter Clutch Pressures 1. Refer to Figure 3–4 for location of pressure taps for range and splitter clutches (manual-hy-draulic models do not have pressure taps for the range clutches).
2. Clutch-apply pressure at all range and splitter clutch pressure taps must equal main pressure (refer to Paragraph 3–11b).
3–12. LINKAGE
a. Manual Selector Valve Linkage (Manual-Hydraulic Models)
1. Refer to the equipment manual for specific link-age adjustment procedures. The following gen-eral procedures are applicable to most equip-ment. The manual selector lever should move easily and give a crisp detent feel in each posi-tion. Adjust the linkage so the stops in the shift selector match the detents in the transmission.
When the linkage is correctly adjusted, the pin which engages the shift lever linkage at the transmission can be moved freely in each range.
2. Proper adjustment of the manual selector valve linkage is important because the shift se-lector detents must correspond exactly to those in the transmission. Make periodic in-spections for bent or worn parts, loose threaded connections, loose bolts, and accu-mulation of grease and dirt. Keep all moving joints clean and well-lubricated.
5600, 5800, 5900, 6000, 6600 SERIES TRANSMISSIONS
b. Retarder Valve Linkage. Clean, inspect, and lu-bricate all linkage. The retarder is not applied when the valve is upward (out of the valve body). For nor-mal operation with the retarder off, it is important that the linkage be adjusted so the valve is held fully up-ward. If the linkage allows the retarder to be partially applied, excessive drag and overheating will result and fuel consumption will be excessive. When the retarder is applied, make sure that the valve is all the way downward. Inspect the control linkage for binding, wear, or breaks. For air cylinder retarder control sys-tems, include a stop to prevent battering the valve against its internal stop.
c. Output Disconnect Linkage
1. Adjust the linkage so that the output is fully connected in the IN position and fully discon-nected in the OUT position.
2. Make periodic inspections for bent or worn parts, loose connections, and accumulation of grease and dirt. Keep moving joints clean and well-lubricated.