Help needed: Transmission problems?

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
cardude01

cardude01

Guru
Joined
Nov 26, 2012
Messages
5,290
Location
USA
Vessel Name
Bijou
Vessel Make
2008 Island Packet PY/SP
Well I thought I had snagged a crab trap line or something, but the diver said nothing was on the shaft.

Getting towed into the Shell Morgan Fuel dock.

And ideas? Transmission is stuck in gear. It got stuck in a lock and I was able to bang on the shift lever to get out if the lock, but that's not working this time.

It's a Yanmar KM4A2 transmission.

Any ideas what it could be? Any repair places around here in Intracoastal City?
 
Last edited:
You've probably done this already, but just checking:

Tranny fluid qty and smell? Does it smell burnt?

Linkage connected at both ends of the cable?

Does the lever at the tranny move when moving the helm shifter? (looking for broken cable)

Has there been indications of difficult shifting or unusual noises recently?
 
FlyWright said:
You've probably done this already, but just checking:

Tranny fluid qty and smell? Does it smell burnt?

Linkage connected at both ends of the cable?

Does the lever at the tranny move when moving the helm shifter? (looking for broken cable)

Has there been indications of difficult shifting or unusual noises recently?
Click to expand...


Fluid clean. No smell.

Linkage connected.

Had difficulty yesterday. When I out it in gear it died once. Today in lock it died and jammed in heat but I was able to manually force trans shift lever and get back in neutral.

I don't know why but I think shaft is hung up. Had shaft work done recently.
 
Last edited:
If you can get the transmission in neutral can you turn the shaft by hand from the engine room? Or maybe with a long screwdriver through the coupling aft of the trans. Maybe disconnect the cable at the trans end try moving it at the helm to see if the cable is binding somewhere. Bad luck! let us know what you find
 
Marine transmissions are made to fail in forward gear as a fail safe. So the problem could be anything.
 
Can you move the shift lever at the transmission after disconnecting the cable?
 
Fail in forward? Not sure I have ever heard that one.

Have heard of them stuck in both and neutral....so maybe just some trannys?
 
Last edited:
As Bob said, disconnect the cable right at the transmission, then with someone else to hit the kill switch if needed (unless it's easily within reach down in the ER,) Shift it from N to F to N then R then back to N. If they all shift freely, then it's not the transmission but the cable. If it won't shift right from the lever, then it does sound like something internal in the Tranny. Clean off the tranny label. Look on ebay to find another one. Then you have the option of getting an ebay one rebuilt, (or checked out) or remove yours and have it rebuilt.
cardude01 said:
I don't know why but I think shaft is hung up. Had shaft work done recently.
Click to expand...

How would a shaft hang up? Maybe the stuffing box is too tight. But I would think that would rip the rubber coupling off the stuffing box/shaft log before it stalled an engine.


Funny thing, you say it stalled out once when going into gear? But not all the time??
 
Last edited:
Made it to the dock. Checking some things out.
 
Well it's not the shaft. Pulled it back and it spins free.

Not the linkage. It's free.

So why, oh why, is my poor little transmission stuck in gear?

?
 
cappy208 said:
As Bob said, disconnect the cable right at the transmission, then with someone else to hit the kill switch if needed (unless it's easily within reach down in the ER,) Shift it from N to F to N then R then back to N. If they all shift freely, then it's not the transmission but the cable. If it won't shift right from the lever, then it does sound like something internal in the Tranny. Clean off the tranny label. Look on ebay to find another one. Then you have the option of getting an ebay one rebuilt, (or checked out) or remove yours and have it rebuilt.

How would a shaft hang up? Maybe the stuffing box is too tight. But I would think that would rip the rubber coupling off the stuffing box/shaft log before it stalled an engine.


Funny thing, you say it stalled out once when going into gear? But not all the time??
Click to expand...


Right. Not all the time. Only did it a couple of times.
 
The guys at Shell Morgan should know someone who can take a look
 
Change the fluid, and make sure the cooling water is flowing into the oil cooler (assuming you have one.) Beyond that, I would imagine a trip to a tranny guy would be in order. Or a good marine mechanic. Hey, can you SEE the post the lever is attached to? Make sure that when you are pushing the lever arm to FNR the rod that goes INTO the tranny is following. Do you have a two helm station boat? If so, make sure the 'other' station that is not being used has the throttle and shift levers free to move fully. I had a solar panel on the FB that had shifted while at anchor. When I went to bring the boat in from the mooring to the dock to pick up the landlubbers (oops, I mean my guests) the shift wouldn't travel fully fwd. It didn't dawn on me why until I went up top to remove the canvas to drive from the FB that the lever was impinged in movement.

But, that still doesn't explain the 'falling in gear, or stalling part......... Hmmmm. Making me think.
 
As cappy suggests make sure the trans lever is not "spinning" on the rod that goes into the trans. If so it could be a sheared key or loose splines. Or the shifting fork inside may be loose.
Good luck
 
Linkage on trans was hung up. Shaft free. Took shifter linkage apart so I could trick it to think it was in neutral and bumped starter. That freed up trans linkage. Put it back together. Works for now.

The thing I don't get is why was it dying at times when shifting into forward? Like a drag on the engine. Caused RPM to fall some other times. Also why was there some vibration that I didn't have before? That's why I thought I had crap on the prop shaft.

The shaft turned when I took it apart from the trans but not very easily. How easy should it be to spin? Now I'm wondering if the diver missed something. The water was like mud.
 
Last edited:
ImageUploadedByTrawler Forum1438221148.866060.jpg

Muddy water he dove into.
 
cappy208 said:
Change the fluid, and make sure the cooling water is flowing into the oil cooler (assuming you have one.) Beyond that, I would imagine a trip to a tranny guy would be in order. Or a good marine mechanic. Hey, can you SEE the post the lever is attached to? Make sure that when you are pushing the lever arm to FNR the rod that goes INTO the tranny is following. Do you have a two helm station boat? If so, make sure the 'other' station that is not being used has the throttle and shift levers free to move fully. I had a solar panel on the FB that had shifted while at anchor. When I went to bring the boat in from the mooring to the dock to pick up the landlubbers (oops, I mean my guests) the shift wouldn't travel fully fwd. It didn't dawn on me why until I went up top to remove the canvas to drive from the FB that the lever was impinged in movement.

But, that still doesn't explain the 'falling in gear, or stalling part......... Hmmmm. Making me think.
Click to expand...


I do see two hoses going to the trans. How do I make sure it has water circulating? Remove a hose?

One station controls.

Worried about this trans now.
 
On our boat those hoses send and return the transmission oil to the oil cooler which has water circulating through it.
 
Cardude,

The Kanzaki KM4A2 has a mechanical cone clutch. If you are able to get the transmission into neutral using the shift lever, the output shaft should spin freely and smoothly with no discernible end play.

Cone clutches can be difficult to disengage if the engine idle rpm is too high, or if there is any significant resistance in the drive line that keeps the cone engaged. The higher the resistance, the tighter the lock up.

I have included a diagram of the shift lever and its alignment/adjustment. Note that in neutral, the lever is exactly horizontal (in line with the crankshaft). Sometimes there is a reference mark on the transmission housing. Also, be careful with the washers under the end bolt. They are actually calibrated spacers that adjust the depth of the shift fork in the cone clutch.

If, as you state, the propeller shaft is hard to turn, it could definitely make the transmission hard or impossible to shift into neutral with the engine running. It could also stall the engine when shifting into gear at idle.

With the transmission in neutral, you should be able to rotate the propeller shaft by hand. Sometimes two hands, but not much more than that. If you need a wrench or lever to turn it, there is something wrong that will require correction. As you mentioned, maybe the diver missed something. With the transmission in neutral he should have been able to easily rotate the prop in both directions. Definitely check the stuffing box adjustment.

If you do need help with the transmission, you can contact the Yanmar Distributor for the Gulf Coast:

Laborde Products, Inc.
74257 Hwy 25
Covington, LA 70435
Toll Free: 1-800-628-9882
Manufacturers Offered: Diesel America, FPT - Industrial, Hatz, Mitsubishi - Industrial, Mitsubishi - Marine, Mitsubishi - Small Bore, SteyrMotors, Yanmar - Industrial, Yanmar - Marine

They advertise certified technicians on call 24 hours a day, 7 days a week.

Hope some of this info helps. Best of luck :thumb:
 

Attachments

  • KM4A.JPG
    KM4A.JPG
    83.4 KB · Views: 203
LarryM said:
Cardude,

The Kanzaki KM4A2 has a mechanical cone clutch. If you are able to get the transmission into neutral using the shift lever, the output shaft should spin freely and smoothly with no discernible end play.

Cone clutches can be difficult to disengage if the engine idle rpm is too high, or if there is any significant resistance in the drive line that keeps the cone engaged. The higher the resistance, the tighter the lock up.

I have included a diagram of the shift lever and its alignment/adjustment. Note that in neutral, the lever is exactly horizontal (in line with the crankshaft). Sometimes there is a reference mark on the transmission housing. Also, be careful with the washers under the end bolt. They are actually calibrated spacers that adjust the depth of the shift fork in the cone clutch.

If, as you state, the propeller shaft is hard to turn, it could definitely make the transmission hard or impossible to shift into neutral with the engine running. It could also stall the engine when shifting into gear at idle.

With the transmission in neutral, you should be able to rotate the propeller shaft by hand. Sometimes two hands, but not much more than that. If you need a wrench or lever to turn it, there is something wrong that will require correction. As you mentioned, maybe the diver missed something. With the transmission in neutral he should have been able to easily rotate the prop in both directions. Definitely check the stuffing box adjustment.

If you do need help with the transmission, you can contact the Yanmar Distributor for the Gulf Coast:

Laborde Products, Inc.
74257 Hwy 25
Covington, LA 70435
Toll Free: 1-800-628-9882
Manufacturers Offered: Diesel America, FPT - Industrial, Hatz, Mitsubishi - Industrial, Mitsubishi - Marine, Mitsubishi - Small Bore, SteyrMotors, Yanmar - Industrial, Yanmar - Marine

They advertise certified technicians on call 24 hours a day, 7 days a week.

Hope some of this info helps. Best of luck :thumb:
Click to expand...


Larry,

I'm a little confused. When I took the shaft off the transmission I could turn it using both hands.

After installing the shaft (last night) and reading your message this AM, I tried with the transmission in neutral and the shaft won't budge.

I was going to run it this morning like it is but now I don't know. Seems like the transmission itself is putting a bind on the shaft somehow, even when in neutral?

I put a call into that place you found, but they are a parts distributor. They directed me to some Yanmar repair places. Waiting on them to open.
 
Last edited:
cardude01 said:
Larry,

I'm a little confused. When I took the shaft off the transmission I could turn it using both hands.

After installing the shaft (last night) and reading your message this AM, I tried with the transmission in neutral and the shaft won't budge.

I was going to run it this morning like it is but now I don't know. Seems like the transmission itself is putting a bind on the shaft somehow, even when in neutral?

I put a call into that place you found, but they are a parts distributor. They directed me to some Yanmar repair places. Waiting on them to open.
Click to expand...

Cardude,

Please clarify the following for me so that I understand completely:

"I'm a little confused. When I took the shaft off the transmission I could turn it using both hands."

I assume you disconnected the propeller shaft from the transmission output shaft coupling.

Which shaft could you "turn using both hands", the propeller shaft or the transmission output shaft on the back of the transmission?

Can you turn the transmission output shaft coupling by hand? In neutral, it should spin easily with little or no resistance and be very smooth.

"After installing the shaft (last night) and reading your message this AM, I tried with the transmission in neutral and the shaft won't budge."

From this, I take it you re-attached the propeller shaft to the transmission output shaft coupling and now you cannot turn the propeller shaft. Presumably, the transmission is still frozen. Is that the case?

"I was going to run it this morning like it is but now I don't know. Seems like the transmission itself is putting a bind on the shaft somehow, even when in neutral?"

If the shift lever on the side of the transmission is really in neutral, and you still can't turn the transmission output shaft coupling when it is disconnected from the propeller shaft, there is some internal fault or failure. Time for service or repair by someone familiar with that transmission, preferably a Yanmar dealer or repair facility. If the bearings or gears fail, in a worst case, they can even crack the aluminum transmission housing which would mean a whole new transmission.

A final thought. Do the transmission output shaft coupling and the propeller shaft couplings align properly? If they are too far out of alignment, I suppose it is possible that the entire engine/transmission/propeller shaft/stuffing box and cutless bearing assembly could be in enough of a bind that you could no longer turn the propeller shaft. This could likely be caused by a loose or broken engine mount.

If that is the case, any good yard should be able to correct it and get you on your way.


Best of luck on this one.
 
Yes the tans output shaft would not turn in neutral.

I decided to suck the oil out of the trans. Where I thought I had clean oil I got this out instead.

ImageUploadedByTrawler Forum1438280234.455719.jpg

I don't know why the oil looked clean on the little dipstick, but it did.

So I refilled with new 30wt and tested it. Ran it in forward tied to the dock. Put in neutral. Shaft spun! Tried it in reverse. Back in neutral. Shaft spins by hand.

Ran it like that at the dock then sucked oil out again and refilled. Seems ok now.

Underway now for two hours. Trans temp 155. Coolant hoses seem to be working at 135deg.
 
Larry, excellent posts. The fact that Bill is not posting suggests he has no service. My last communication with him is the prop shaft was turning freely but the clutch side not. He apparently flushed the tyranny about 4 times, getting a lot of trash initially. This seemed to free it up. All fluids were changed 200 hrs ago. He was through the lock and on his way around 9 this morning so is currently in the middle of nowhere. I am sure he will post back as soon as he has service.

He's back! Lol
 
And now my autopilot is hunting around like a drunken sailor. I swear. If it's not one thing....

When I was anchored the barges pushed me into the mud once and the rudder bumped lightly. Is that a clue?
 
If it's fine when you hand steer then it's not external damage IMO.
 
Could be the compass.
 
I did a bad cal on my autopilot. It worked great on almost all headings. Then one time I needed to go I think 300deg, it cycled like nuts. Back to 270, it was great. Redid cal and it was fine at 300.

So are you running a heading that you have not tried before?
 
I don't think I'm running a weird heading. Seems like about the same heading I've been running. That's why I can't figure out why it's veering from side to side so bad now when before it was holding perfectly
 
CD.... What was cause of original "shaft needed repair"???
 
You must log in or register to reply here.

Similar threads

hobbystuff
Lehman 120 - Paragon P200 P23L Transmission Needed
Replies
3
Views
849
appdiver
A
Slo-Mocean
Thoughts on leasing out my trawler for Loopers
2
Replies
52
Views
4K
jdemere
J
garmstro55
Yanmar Elbows - Do these need replacing?
Replies
9
Views
1K
boatnbump
boatnbump
A
Teleflex/ Morse transmission cable need help
Replies
4
Views
1K
tiz
T
R
Grand Banks 42 Swim Step / Water Tank Help!
Replies
20
Views
3K
RyanZ
R

Latest posts

Back
Top Bottom