mattis75

I have just put in a mercruiser transII in my boat and when I put in reverse the propeller starts with full power,but when I push into forward the propeller starts slowly and powerless. I can stop the prop with a stick in forward mode. I have tried direct on the tranny, on the shifter, and Im sure that the shifter is in its right position. Can anybody please help me?
P.s. To everybody who read my last message,I looked wrong on the prop. Guess if I was confused when I put the gear in and the boat went backwards and not forward.
Best regards from
Panthera 24 w/ 6.5l supercharged diesel 300hp 680nm and TRS drive .
And the boat is in Sweden

FWK

If i is not producing enough pump pressure it wil not engage the plates. Check WHITE-DIAMONDS post with some of these issues. it could also just need a new set of plates. Interesting combination for power.

Mbam

I hate to say this, but I don't think that transmission will handle the torque. That is about 525 ft lbs.

Also do you mean that the boat goes backward when you have the transmission in forward?

mattis75

no the boat only goes backward when i put in forvard but when i put in forvard the prop is runing forvard but slowly and powerles

Mbam

Does it go backwards when in reverse?

mattis75

Yes the boat goes backwards when i reverse

martiniboat

I've rebuilt one of those transmissions before. If I remember correctlly the pump should put out around 90psi. and it's easy to test as well. There is a 1/8 NPT plug right beside the 'safety start' switch. Tap into that with a guage to see where you're at. The picture shows the elbow with a 6" pipe on it that leads to a guage. I keep it there permanently to monitor the pressure all of the time. Hope this helps.

Sincerely,
Brian Kamrath

Audiofn

Martini that is a great idea thanks for the idea

spectra32

This is straight from the Mercruiser book...Look at the type of oil, and the pressures you have.

The direct drive transmission consists of a planetary gear set,
forward multiple disc clutch, reverse band clutch, oil pump,
pressure relief valve, rotary control valve and electric shift
motor. All, except the shift motor, are contained in aluminum
housing and provide forward, reverse and neutral operation.


PRECAUTIONS
6.
Change oil once each season.
Check oil level at normal engine operating temperature
immediately after engine has been shut off.
Use clean containers for handling transmission fluid.
Fill transmission before starting engine.
Use only automatic transmission fluid (ATF) Type "A"
Suffix "A" or Ford Dextron.
If transmission malfunctions, check transmission oil pressure
and temperature. Normal pressures and temperatures
are as follows:
a. Oil temperature at normal engine operating temperature
should not exceed 190°F (88°C). Oil temperature
should be measured by removing plug from oil cooler
(Figure 2 - "Transmission Reassembly") and installing
suitable temperature gauge.
b. Oil pressure at 750 RPM is 80-105 PSI (5.62-7.38
kg/cm2). Oil pressure is measured by removing plug
from control valve housing (Figure 4 - "Transmission
Disassembly and Repair") and installing suitable
pressure gauge. (Elbow C-22-54035 may be installed
for ease of gauge connection. After test, plug re-
moved from housing can be replaced in elbow.)
c. After shifting, and pressure has stabilized, pressure
must not fluctuate more than 5 PSI (.35kg/cm-) when
shifting from forward to neutral to reverse.
d. Oil pressure in forward gear at 4000 RPM is 120-145
PSI(8.44-10.19kg/cm2).
7. Except in emergency, never shift at engine speeds above
1500 RPM.
8. Do not permit propeller shaft to rotate for extended
periods of time when transmission is inoperative. This
propeller shaft rotation could be caused by towing or
operation of a second engine that causes the propeller to
"windmill". An inoperative stern drive should be tilted up
to "trailer" position to prevent "windmilling".
9. Do not mix types or brands of automatic transmission
fluid.
10. Never remove oil cooler hoses or use smaller-thanrecommended
3/8" (9.5mm) inside diameter cooler hoses
when operating transmission.
11. Check engine alignment each time engine is replaced.

spectra32

I hope this helps. Let me know if you need more info.

Joel

MerCruiser II-TR Transmission Model A Malfunctions (aka MercTrans II)

1. Transmission Malfunctions in Neutral
1.1. Output shaft drags excessively in forward direction
1.1.1. Electronic control box and shift motor not working
1.1.2. Forward clutch pack improperly assembled
1.1.3. Damaged or broken forward clutch return spring
1.1.4. Damaged clutch plates
1.2. Output shaft drags excessively in reverse rotation
1.2.1. Reverse clutch lever not free
1.2.2. Incorrect reverse band adjustment
1.2.3. Improperly assembled reverse clutch band assembly
2. Transmission Malfunctions in Forward
2.1. Low oil pressure
2.1.1. Low oil level
2.1.2. Dirty oil screen
2.1.3. Worn or misaligned output sleeve in trans. housing
2.1.4. Worn or damaged Teflon seal rings
2.1.5. Worn or broken oil pump
2.1.6. External oil leak
2.1.7. Internal oil leak
2.1.8. Relief valve stuck
2.2. Forward clutch engages improperly
2.2.1. Electronic control box and shift motor not working
2.2.2. Control valve assembled improperly
2.2.3. Worn or misaligned output sleeve in trans. Housing
2.2.4. Worn or damaged clutch piston oil seals
2.2.5. Worn or damaged Teflon seal rings
2.2.6. Forward clutch pack improperly assembled
2.2.7. Damaged or broken forward clutch return spring
2.2.8. Worn or damaged clutch plates
2.2.9. Broken piston housing
2.3. Forward clutch slips (fails to fully engage)
2.3.1. Electronic control box and shift motor not working properly
2.3.2. Forward clutch pack improperly assembled
2.3.3. Damaged or broken forward clutch return spring
2.3.4. Worn or damaged clutch plates
3. Transmission Malfunctions in Reverse
3.1. Low oil pressure
3.1.1. Low oil level
3.1.2. Dirty oil screen
3.1.3. Worn or broken oil pump
3.1.4. External oil leak
3.1.5. Internal oil leak
3.1.6. Relief valve stuck
3.2. Reverse clutch engages improperly
3.2.1. Electronic control box and shift motor not working properly
3.2.2. Incorrect reverse band adjustment
3.2.3. Control valve assembled incorrectly
3.2.4. External oil leak
3.2.5. Internal oil leak
3.2.6. Worn or damaged reverse clutch band assembly
3.2.7. Planetary gear failure (you don't want this )
4. Transmission Malfunctions in ALL RANGES
4.1. No oil pressure
4.1.1. No oil or oil level very low
4.1.2. Broken pump
4.1.3. Sheared pump drive key
4.1.4. Relief valve stuck
4.2. Low oil pressure
4.2.1. Low oil level
4.2.2. Dirty oil screen
4.2.3. Worn oil pump
4.2.4. Relief valve stuck
4.3. High oil temperature
4.3.1. Oil level very low
4.3.2. Dirty oil cooler or blocked oil line
4.4. Does not shift
4.4.1. Electronic control box and shift motor not working properly
4.4.2. Control valve assembled incorrectly
5. Internal & External Leaks
5.1. Oil leaks at control valve
5.1.1. Oil passage plugs leaking
5.1.2. Loose bolts
5.1.3. Damaged O-rings
5.1.4. Damaged gasket or foreign material on mating surfaces
5.1.5. Porous control valve housing
5.2. Oil leaks at pump
5.2.1. Damaged O-rings
5.2.2. Loose bolts
5.2.3. Damaged or worn oil seal
5.2.4. Relief valve or oil discharge passage plug leak
5.2.5. Damaged gasket or foreign material on mating surfaces
5.2.6. Porous control valve housing
5.3. Oil leaks at output housing
5.3.1. Loose bolts
5.3.2. Damaged O-ring
5.3.3. Damaged or worn oil seal
5.3.4. Porous output housing
5.3.5. Foreign material on mating surfaces
5.3.6. Oil passage ball plug improperly seated
5.4. Oil on exterior of transmission
5.4.1. Dipstick tube leaks
5.4.2. Loose bolts
5.4.3. Damaged gasket or foreign material on mating surfaces
5.4.4. Damaged O-rings
5.4.5. Porous housings
5.4.6. Damaged oil seal
5.4.7. Oil passage plugs leaking
5.5. Water in oil
5.5.1. Damaged oil cooler
6. Misc. trans problems
6.1. Oil foaming
6.1.1. High oil level
6.1.2. Air in oil
6.1.3. Dirty oil screen
6.2. Gear noise in reverse
6.2.1. Nicks on gears
6.2.2. Planetary gear failure
6.3. Pump noise
6.3.1. Low oil level
6.3.2. Dirty oil screen
6.4. Flywheel drive plate noise or failure
6.4.1. Flywheel drive plate assembly damaged
6.5. High oil pressure
6.5.1. Wrong oil used in trans.
6.5.2. Cold oil
6.5.3. Relief valve stuck
6.6. Smoking
6.6.1. Low oil level
6.6.2. Electric shift motor not working properly
6.6.3. Reverse clutch lever not free
6.6.4. High rotational speed in reverse