DRESSTA TD-25M EXTRA, Service Manual

Page: 74 / 595

SECTION 7
DRIVE TRAIN
Page 22
TD-25M EXTRA DRESSTA
SERVICE DIAGNOSIS
PROBLEM PROBABLE CAUSE
6. Low or zero, each (FR)
directional and (PC) range
clutch oil pressure.
a. Low main oil pressure. Refer to problem 1 above.
b. No or low signal oil pressure from drive train control valve. Tee
in a 3000 [kPa] test pressure gauge at the F or R port on the
range selector valve and check for oil pressure. If low, repair
or replace the drive train control valve.
c. Stuck switch spool in range selector valve.
d. Rate of rise valve damaged.
e. Screen under rate of rise valve clogged.
7. Low or zero pressure at
both forward and reverse
clutch
a. Leaking manifold seal ring between F and R gear on input
shaft. Perform “Five Penny” Test described in this Section.
8. Low or zero pressure at
both 2nd and 1st or 1st and
3rd
a. Leaking manifold seal ring gear on output shaft (between
2 and 1 or 1 and 3). Check manifold and seal rings condition;
refer to SECTION 7C, TRANSMISSION.
b. Perform “Five Penny” Test described in this Section.
9. Low or zero one of F or R
clutch pressure
a. No or low signal oil pressure from drive train control valve.
Tee in a 3000 [kPa] test pressure gauge at the F or R port on
the range selector valve and check for oil pressure.
b. Range selector valve directional spool damaged.
c. Leaking one of manifold outside seal gear (F, R) on input
shaft. Perform Five Penny Test described in this Section.
d. Leaking one of directional clutch pack. Perform Five Penny
Test described in this Section.
10. Low or zero one of 1st,
2nd or 3rd clutch pressure
a. Faulty solenoid valve on gear shifting valve (2nd or 3rd).
b. Range selector valve range spool damaged.
c. Leaking one of outside manifold seals on output shaft (for 2nd
or 3rd gear only). Check manifold and seal rings condition;
refer to SECTION 7C, TRANSMISSION.
d. Perform “Five Penny” Test described in this Section.
11. TORQUE CONVERTER STALL SPEED CHECK
WARNING! Be sure the area around the machine is clear of personnel and
obstructions as the machine may move during this check.
1. Use the Digital Optical Tachometer (refer to SERVICE /SPECIAL TOOLS in this Section).
2. With the engine speed at full throttle and the foot brake applied, shift the transmission into third
forward and record the stall speed RPM.
3. If the stall speed meets specifications, proceed with Par. 12, DRIVE TRAIN CLUTCH TEST.
4. If the stall speed does not meet specifications, refer to the following chart.
Torque Converter Stall Speed Chart
PROBLEM PROBABLE CAUSE
1. Stall speed too high
a. Engine injection pump defective or improperly adjusted.
b. Refer to Par. 12, DRIVE TRAIN CLUTCH TEST.
2. Stall speed too low a. Too low engine power. Refer to ENGINE REPAIR MANUAL.