This section describes routine proceduresto maintain the transmission in good opera-ting condition. Included are instructions forcare of the oil system, minor adjustments ofthe transmission and control linkage, tests todetermine condition, instructions for extendedstorage, and a troubleshooting chart.

The transmission should be kept clean tomake inspection easier. Check for loosebolts, loose oil lines, oil leakage, and condi-tion of control linkage and cables. Check thetransmission oil level daily.

a. Importance of Proper Oil Level

(I) Maintaining the proper oil level isvery important. The transmission oil is usedto apply clutches and lubricate and cool thecomponents. Transmission performance willbe affected when' the oil aerates. The pri-mary causes of aeration are low oil in thesump or too much oil in the sump.

(2) A low oil level can cause the in-put pump to cavitate, causing irregular oper-ation. The aeration also changes the viscos-ity and color of t he oil to a thin milky liquid.

(3) Too much oil in the sump can in-troduce oil into the gearing and clutches.This can cause aeration which can overheatthe transmission or cause irregular operation.

2.. Location of Oil Gauge Rod. M10 mod-els have an oil gauge rod (dipstick) loca ted atthe rear face of the flywheel housing. Allother models have an oil gauge rod on theright or left side of the reduction gear hous-ing (fig. 3-1).

c. Oil Check. The oil level check shouldbe maae with the engine running after a fewminutes running time with the transmissionat normal operating temperature (180-200oF;

83-93°C). The oil level should be checkeddaily. For horizontal applications, keep theoil level to the FU LL mark on the oil gaugerod. For nonlevel applications the oil levelshould be raised l/16-inch above the FU LLmark per degree of angularity. If the powerpack is set at an angle, a true FULL markmay t1e established on the oil gauge rod afterthe boat is afloat.

a. Cleanliness. Oil must be handled inclean containers to prevent foreign materialfrom entering the transmission.

Containers or filters that havebeen used for antifreeze or en-gine coolant solution must notbe used for oN.

!?. Oil Capacity. Refill the transmissionto the FULL mark on the dipstick.

r,

U.s. QuartsSeries Approx.

M 6MH shallow profile 6MH deep profile 6.5

5.55.56

Recheck the oil level after the transmissionis up to normal operating temperature (180-200°F; 83-93°C) and while the engine is run-ning.

c. Recommended Oil. Use the same typeand-SAE viscosity oil used in the engine. C-3oil should not be used in Allison marine trans-missions. Refer to DDA Engine Oil Spec 7SE270.

£. Cold Weather Start-up. Listed beloware the minimum water temperatures atwhich the [X)wer~ck may be safely operated.When water temperature is below the mini-mum temperature limit and the transmissionis cold, preheat is required. If auxiliary heat-ing equipment is available, preheat the oil to

the minimum temperature limit. If auxiliaryheating equipment is not available, run theengine for at least 20 minutes with the trans-mission in neutral before operating in for-ward or reverse. Failure to observe the mini-mum temperature limit can result in trans-mission malfunction or reduced transmissionIi fe.

Engine OilViscosity

WaterTemperature

SAE 40SAE 30SAE l5W-40

500P (lOoC)320P (ooC)32°P (O°C)

e. Intervals. The oil and oil filters shouldbe changed every 500 hours or once a year de-pending on type of duty and environment.Heavy sludge deposits found on the oil filterelement at the time of an oil change indicatesthat the detergency of the oil has been ex-hausted. When this occurs, the oil change in-terval should be shortened. Replacement ofthe oil filter element at the time of the oilchange ensures the removal of abrasive dustand metal particles.

(1) The transmission should be at op-erating temperature (after about one houroperation).

(2) Remove the oil drain plugs fromthe sump and oil filters (fig. 3-1) and drainthe oil. Replace the plugs.

(3) Clean the transmission strainerassembly thoroughly (fig. 3-1). A new gasketshould be used when replacing the cover aftereach cleaning.

(4) Filter elements should be replacedwhenever the oil is changed. The filter shellsshould be thoroughly cleaned. New gaskets(or sealrings) should be used when new filterelements are installed.

(5) Before starting the engine, removethe breather and refill the transmission withclean oil (para 3-4Q and ~.

(6) When refilling the system, pourenough oil into the transmission to bring theoil level up to the FULL mark on the oil gaugerod. Start the engine, and let it idle for twoor three minutes with the transmission inneutral. Recheck the oil level, and if neces-sary add oil to bring it up the FULL mark onthe oil gauge rod. Do not overfill the trans-mission.

(7) Carefully inspect the filter com-ponents and cover for oil leakage while theengine is running.

!:!.. Examine at Oil Change. At each oilchange, examine the oil which is drained forevidence of dirt or water. A normal amountof condensation will emUlsify in the oil duringoperation of the transmission. However, ifthere is evidence of water, check the coolerfor leakage between the water and oil areas.Oil in the water side of the cooler is anothersign of leakage. This, however, may indicateleakage from the engine oil system.

(1) Metal particles in the oil (exceptfor the minute particles normally trapped inthe oil filter) indicate damage has occurredin the transmission. When these particles arefound in the sump, the transmission and fly-wheel assembly must be disassembled and

closely inspected to find the source. Metalcontamination will require complete disas-sembly of the transmission and flywheel as-sembly and cleaning of all internal and exter-nal circuits and all other areas where theparticles could lodge. During the repair of amajor internal failure of a transmission, itshould be dismantled into as many service-able detail parts as possible and thoroughlycleaned. Do not disassemble the unit just tothe problem area.

(2) Do not attempt to clean the oilcooler after a transmission failure has oc-curred which has released metal particlesinto the system. In this instance, the coolercore (element) should be re placed.

(1) If coolant leaks into the transmis-sion oil system, immediate action must betaken to prevent malfunction and possibleserious damage. Glycol will attack friction-faced clutch plates. The transmission andflywheel assembly must be completely disas-sembled, inspected and cleaned. If glycol ispresent, both forward and reverse friction-faced clutch plates must be replaced. Alltraces of the cool~nt, and varnish deposits,resulting from coolant contamination, mustbe removed. The cooler should be repaired orreplaced prior to installation of the new orrebuilt transmission.

Check all oil lines and connectors for signsof leakage and for worn or damaged hoses(fig. 3-1).

The breather is located at the top rear ofthe transmission housing (fig. 3-1). Thebreather prevents pressure buildu p within thetransmission. The breather must be removedto access the transmission oil fill tube. Thebreather must be kept clean., The prevalenceof dust and dirt will determine how often thebreather requires cleaning.

3-8. CHECKING OIL PRESSURES,TEMPERATURE

a. Oil Pressure. In s 0 m e boats, a linefrom the selector valve connects to a trans-mission oil pressure gag e at the controlpanel. Refer to figure 3-1. Transmission oilpressure in forward, at 1800 rpm should read130 psi (896 kPa); in reverse, at 1500 rpmshould read 110 psi (758 kPa) •.

E. Oil Temperature. In s 0 m e boats, aline from the cooler inlet line connects to atransmission temperature gage at the controlpanel. Normal operating temperature forAllison Marine Transmissions is 180-200oF(83-93°C).

a. The manual selector lever should moveeasily and give a crisp detent feel in forward,neutral, and reverse positions (fig. 3-2). Thelinkage should be adjusted so the stops in theshift tower match the detents in the trans-mission.

b. Periodic inspections should be madefor -bent or worn parts, loose threaded con-nections, loose bolts, or accumulation ofgrease and dirt. All moving joints must bekept clean and well lubricated.

a. Stor e New Transmission (prior toinstallatio • New transmissions are testedat Detroit Diesel Allison with preservativeoil and drained prior to shipment. The resid-ual oil remaining in the transmission providesadequate protection to safely store the trans-mission for up to one year (stored inside inconditions of normal climate and with allshipping p 1 u g s installed) without furthertreatment.

TRANSMISSIONHOUSING

~

O.

FORWARD ~ \ " .

, \

"

Fig. 3-2. Adjustment of selectorvalve lever and linkage

b. Preservation Methods. When the trans-mission is to be stored or remain inactive foran extended period (one or more years), spe-cific preservation methods are recom mendedto prevent damage due to rust, corrosion, andorganic g row thin the oil. Preservationmethods are presented for storage with andwithout oil. .

(2) Spray two ounces (60 milliliters)of VCI #l0® through the fill tube.

(3) Seal all openings and the breatherwith moisture-proof tape.

(4) Coat all exposed, unpainted sur-faces with preservative grease such as petro-leum (MIL-C-ll 796, Class 2).

(5) If additional storage time is re-quired, repeat steps (2), (3) and (4) at yearlyintervals.

®VCI #10 is the registered trademark for a vapor phase rust preventive manufactured byDaubert Chemical Company, Chicago, Illinois. Motorstor VCI #10 is covered by MilitarySpecifications MIL-L-46002 (ORD) and MIL-I-23310 (WEP) under the designation of NucleOil.

d. Storage, One Year-With Oil (normallyinstalled in the powerpack)

(1) Drain the oil and replace the oilfilter element(s).

(2) Fill the transmission to operatinglevel with a mixture of one part VCI #10 (orequivalent) to 30 parts engine oiL Add 1/4teaspoon of Biobor JF® (or equivalent) foreach 3 gallons (11 liters) of oil in the system.

When calculating the amount ofBiobor JF r e qui red, usethe total volume of the system,not just the quantity requiredto fill the transmission. Includeexternal lines, filters, and thecooler.

(3) Run the engine for approximatelyfive minutes at 1500 rpm with the transmis-sion in neutraL

(4) Shift the transmission from for-ward to neutral and then to reverse.

(5) Continue running the engine at1500 rpm with the transmission in neutralu n t i 1 normal operating temperature isreached.

(6) As soon as the transmission iscool enough to tOUCh, seal all openings andthe breather with moisture-proof tape.

(7) Coat all exposed, unpainted sur-faces with preservative grease such as petro-latum (MIL-C-U796, Class 2).

(8) If additional storage time is re-quired, repeat steps (2) through (7) at yearlyintervals; except, it is not necessary to drainthe transmission each year. Just add Motor-stor and Biobor JF (or equivalents).

(1) Remove all tape from openingsand the breather.

(2) Wash off all external grease withmineral spirits.

(3) If the transmission is new, drainthe residual preservative oiL Refill thetransmission to the proper level with engineoiL

(4) If the transmission was preparedfor storage without oil, drain the residual oiland replace the oil filter elements. Refillthe transmission to the proper level with newengine oil.

(5) If the transmission was preparedfor storage wit h oil, it is not necessary todrain and refill the transmission with new en-gine oil. Check for proper oil leveL Add ord r a i n oil as required to obtain the properlevel.

(1) Do not r'operate the powerpackprior to completing the procedures describedin this paragraph. Inspect for oil leakage.Visually inspect all splitlines, plugs, and hoseand tube connections at the transmission andcoole r. Oil leakage at splitlines may becaused by loose mounting bolts or defectivegaskets. Tighten all bolts, plugs and connec-tions where leakage is found. Check the se-lector valve linkage for proper operation(para 3-9).

(2) The engine and transmission mustbe regarded as a sin g 1 e package duringtroubleshooting. A thorough s t u d Y of thedescription and operation of the componentsand hydraulic system will be helpful in deter-mining the cause of trouble.

®Biobor JF is the registered trademark for a biological inhibitor manufactured by U.S. Boraxand Chemical Corporation.

b. During Operation

(1) If inspection (para 3-11a) does notreveal the cause of trouble, and the craft isoperational, further troubleshooting is neces-sary. Do not remove the transmission fromthe craft u n t i 1 the causes of trouble arechecked against the troubleshooting chart.

(2) To make a thorough running checkof the transmission, be sur e the engine isproperly tuned and the oil level in the trans-mission is correct. Refer to paragraph 3-3for checking the oil level.

c. After Removal from Craft. When themaifuncton of the transmission is not ascer-

tained by tests or inspections before removalfrom the era f t, the transmission may bemounted in a test stand and checked (if a tests tan d is available). Particular attentionshould be given to proper oil level and to cor-rect linkage adjustment in every transmissiontest.

.9.. Troubleshooting Table. Table 3-1 out-lines the possible c a use s of transmissiontroubles and their remedies. Capital lettersindicate the symptom; numerals following thesymptom indicate several possible causes;corresponding numerals in the right columnindicate remedies for the causes and directyou to information.

3. Clean dump valve thoroughly and replacedamaged parts.

5. Manual selector valve notpositioned properly

2. Replace oil gage or, if the oil gage is slowto register, bleed the oil gage line to re-move entrapped air or obstruction.

3. Check the oil temperature and if found tobe abnormally high, remove the transmissionoil cooler and clean internally and exter-nally. Replace the cooler if necessary.

4. Shim the pump. Refer to engine servicemanual.

5. Check suction line, flange, pump,pump lines.

1. Broken or worn forward pistonsealrings

3. Clean dump valves thoroughly and replacedamaged parts.

4. Replace loose or missing oil passage plugs.Check emergency engagement bolts fortightnes~ Tighten loose bolts.

1. Broken or worn reverse pistonsealrings

G DRIVE SHAFT ROTATES WITH SELECTOR VALVE IN NEUTRAL AFTER SHIFTING FROMFORWARD TO NEUTRAL

1. Sticking forward clutch plate 1. Replace clutch plate.

2. Damaged forward clutch plate 2. Replace clutch plate.

3. Damaged forward piston drive pins 3. Replace damaged drive pins.

4. Damaged forward piston 4. Replace piston.

5. Damaged planetary assembly 5. Repair or replace planetary assembly.

6. Improper dump valve operation 6. Clean dump valve thoroughly and replacedamaged parts.

7. Faulty drive shaft sealrings 7. Replace sealrings.

8. Control linkage out of adjustment 8. Check linkage adjustment.

H DRIVE SHAFT ROTATES WITH SELECTOR VALVE IN NEUTRAL AFTER SHIFTING FROMREVERSE TO NEUTRAL

1. Sticking reverse clutch plate 1. Replace clutch plate.

2. Damaged reverse clutch plate 2. Replace clutch plate. r,

3. Damaged reverse piston drive pins 3. Replace damaged dri ve pins.

4. Damaged reverse piston 4. Replace piston.

5. Damaged planetary assembly 5. Repair or replace planetary assembly.

6. Control linkage out of adjustment 6. Check linkage adjustment.

1. Low oil pressure 1. Refer to D, b or f.2. Damaged forward piston or clutch 2. Replace piston or clutch plate.

plate

3. Worn forward clutch facings 3. Replace clutch plate.

4. Improper dump valve operation 4. Clean dump valve thoroughly and replacedamaged parts.

5. Worn piston sealrings 5. Replace sealrings.

6. Low oil temperature 6. Use recommended oil. Preheat if required.

1. Low oil pressure 1. Refer to D, §.~or F.

2. Damaged reverse piston or clutch 2. Replace piston or clutch plate.plate

3. Worn reverse clutch facings 3. Replace clutch plate.

4. Worn piston sealrings 4. Replace sealrings.

5. Low oil temperature 5. Use recommended oil. Preheat if required.

6. Worn driveshaft sealrings. 6. Replace sealrings.

3. Reduce load.

4. Correct engine overheating.

5. Clean or replace cooler or lines.

6. Add coolant, check for leaks.

7. Correct leaks.

B. Refer to D, §., or K.

9. Refer to I or J.

10. Clear a way obstruction.

1. Change oil; use proper type (para 3-4).

2. Restore proper oil level (para 3-3).

3. Check oil pump bolts and gasket.

1. Completely disassemble, clean, and repairtransmission. Replace filters and transmissionoil cooler. Clean all external lines.

1. Completely disassemble and thor0ughly cleantransmission. Replace both forward andreverse clutch plates. Repair or replacecooler. Replace filters. Clean all externallines.