Volvo MS4. Gearbox

Colin K

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Hello,
Well started the summer hols and boat all loaded up even the gircast is modetating.
Short hop down the Orwell as. a taster and midday today set off South. 5 miles out to see we opened her up and all good until after a couple of minutes we came off the plane and lost drive to one screw.
Limped home up the Orwell under one engine and each left turn needed to do a circle to get her round but she got us home.

Sat back on our berth,Engine starts great and morse moves the box lever into gear but no clonk either fwd or reverse. No clanking or grinding if it was a car it would be the vclutch plate gone.
Think the hols are shot but wondered if anyone had an idea whats broke.

Cheers, Colin.

Ps we are now going to the pub to discuss options whilst the kids trash the boat. ����
 
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Could be your damper plate which has failed, this will be visible when the box is removed
If you pm me your mob number I'll send you a full manual for the gearbox
Regards Gerry
 
Hello,
Well started the summer hols and boat all loaded up even the gircast is modetating.
Short hop down the Orwell as. a taster and midday today set off South. 5 miles out to see we opened her up and all good until after a couple of minutes we came off the plane and lost drive to one screw.
Limped home up the Orwell under one engine and each left turn needed to do a circle to get her round but she got us home.

Sat back on our berth,Engine starts great and morse moves the box lever into gear but no clonk either fwd or reverse. No clanking or grinding if it was a car it would be the vclutch plate gone.
Think the hols are shot but wondered if anyone had an idea whats broke.

Cheers, Colin.

Ps we are now going to the pub to discuss options whilst the kids trash the boat. ����

Cone clutch for a guess, have you manually shifted the gearbox at the control lever side of gearbox.

Drain the oil and see what colour it is.
Get the box out and bring it to me , I've many scrap parts from various boxes for parts.
 
Could be your damper plate which has failed, this will be visible when the box is removed
If you pm me your mob number I'll send you a full manual for the gearbox
Regards Gerry

To check the damper plate is still good you can place it in gear then turn the output shaft by hand , if it locks up it's not the damper plate .turn it both ways in forward and reverse before you remove the box.
 
If the damper has failed would it lock up when turning the output shaft when in gear?

If damper plate is ok by turning the shaft both ways in gear it should lock up as it's trying to turn the engine, what you are doing is engaging the cone into the respective gear cup, it it spins both ways there is a problem, could still be gearbox though.
Do this without engine running of course , when I say shaft I mean propeller shaft.

Another test is to take top cover off box, select gear and rotate the big top nut and look if prop shaft turns , this will test the bottom gear set which is in effect a crown wheel and pinion, I've seen the vertical shaft shear many times as there is no splined sleeve as per an outdrive .
 
Thanks chaps,
Morse controls work levers work on box just no drive bit of a box smell when we came off the plane??

Cheers
 
Ha ha Thanks for noticing. Yup got a leaky shaft seal on the port box and got a tupperware tray under it. It leaks but just a bit. When the starboard shaft stopped I was gob smacked and for the fifteen miles home thought aaaaah leaking gearbox on my good engine.....
Appreciate both of you chaps helping. Tomorrow top of box open I think its only a cpl of bolts and look at the oil. We are going to chill for a cpl of days here. I always change the box oils every year with the engine oils so it should be clean!!! The gang are reserching cottages in Devon fair enough! Thats where we were hoping to get to.

I quickly opened the dip stick to the box and there was a definate hiss as i cracked the seal (hot still) ? I always suck out the oil and not sure if there is a drain plug.

I must confess I am glad she will motor in a fashion ahead under one engine but by Joe it needs a lot of concentration. All good learning management says!!!!

Cheers, Col.
 
Ha ha Thanks for noticing. Yup got a leaky shaft seal on the port box and got a tupperware tray under it. It leaks but just a bit. When the starboard shaft stopped I was gob smacked and for the fifteen miles home thought aaaaah leaking gearbox on my good engine.....
Appreciate both of you chaps helping. Tomorrow top of box open I think its only a cpl of bolts and look at the oil. We are going to chill for a cpl of days here. I always change the box oils every year with the engine oils so it should be clean!!! The gang are reserching cottages in Devon fair enough! Thats where we were hoping to get to.

I quickly opened the dip stick to the box and there was a definate hiss as i cracked the seal (hot still) ? I always suck out the oil and not sure if there is a drain plug.

I must confess I am glad she will motor in a fashion ahead under one engine but by Joe it needs a lot of concentration. All good learning management says!!!!

Cheers, Col.

No need to suck oil out there is a drain plug at the bottom .
 
Hello,
Thanks for that. Yup found it I have just started we have decided to find out whats gone bang before we jump into the car and head south.
Just started and took off the dip stick. Wow what a smell more like a sewer than oil !! And under quite some pressure so much so I took it off pretty slowly. Where on earth is the pressure coming from? Took off the engine water header cap and no oil in there.
To be continued I recon your right Paul snapped shaft somewhere if it was a cog thing there would be some grinding?

Cheers, Colin.
 
If damper plate is ok by turning the shaft both ways in gear it should lock up as it's trying to turn the engine, what you are doing is engaging the cone into the respective gear cup, it it spins both ways there is a problem, could still be gearbox though.
Do this without engine running of course , when I say shaft I mean propeller shaft.

Another test is to take top cover off box, select gear and rotate the big top nut and look if prop shaft turns , this will test the bottom gear set which is in effect a crown wheel and pinion, I've seen the vertical shaft shear many times as there is no splined sleeve as per an outdrive .


Hello,
Ok results.

Oil is pretty smelly and black no bits of anything in it mind, clean on the dipstick.

Turned prop shaft by hand engaging with the morse and then manually with morse disconnected nothing engages.

Top cover off into gear it locks one way then the other in F/R did not turn shaft but I dont have a big socket/spanner just grips so I might be a wimp! Oddly I turned the prop shaft and at first it turned the nut but now it just twitches.

Wondered if anything can be worked out from that? Looks like the box comes out easy? Six bolts onto the engine water pipes,morse and eight prop bolts. Will the prop shaft move out enough for the main shaft to clear the engine spline?

Thanks, Colin.
 
Hello,
Ok results.

Oil is pretty smelly and black no bits of anything in it mind, clean on the dipstick.

Turned prop shaft by hand engaging with the morse and then manually with morse disconnected nothing engages.

Top cover off into gear it locks one way then the other in F/R did not turn shaft but I dont have a big socket/spanner just grips so I might be a wimp! Oddly I turned the prop shaft and at first it turned the nut but now it just twitches.

Wondered if anything can be worked out from that? Looks like the box comes out easy? Six bolts onto the engine water pipes,morse and eight prop bolts. Will the prop shaft move out enough for the main shaft to clear the engine spline?

Thanks, Colin.
Shaft should slide back enough as long abs you don't have the crane type dripless stern glands as rope cutters of the ambassador type.
Sounds to me your problem is the bottom gear set , tell me which ratio box you have I'd gues 2.63/1
 
Thanks,
Roast dinner on board tonight so I will troll through my boat file think you are right with the ratio. Is it stamped on the box too? Now call me stupid but why does the morse on one box push forward into ahead and the other backwards?
It was great fun coming the length of the river Orwell under one screw with a mighty wind once I had to do a circle to turn her to port. And a Saturday so all the raggies tacking. I think that I had the worst screw out of commission but I will need to stare at my props to work that out. To manouver into my berth I reversed the dinghy on the davits to lean against a pontoon pile to turn her great fenders dinghys!! wish I had filmed it ha ha.
Stern gland all standard and no rope cutter.

Thanks for all your help, Colin.
 
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Thanks,
Now call me stupid but why does the morse on one box push forward into ahead and the other backwards?


Thanks for all your help, Colin.

Engines turn the same way .
Props turn from the middle out .
So the port prop turns anticlockwise and the Stb prop clockwise .
So one of the boxes to counter the same direction of the engine .
 
If the gearbox has been building pressure and the oil has been cooked black and smelly, it sounds like it's been getting very hot.

Is the cooling OK?
 
If the gearbox has been building pressure and the oil has been cooked black and smelly, it sounds like it's been getting very hot.

Is the cooling OK?


Gosh fair point. No pressure at all from the other box. I have not looked but Im guessing its cooled by the engine cooling water as opposed to raw water from the impeller/strainer?? In the morning we lift out the offending box and so will be taking off the water feed/return so perhaps some clues then.
I cannot help but be humble I have been told to get it all disconnected in the morning and lunchtime Wife/17 yr old daughter/10 yr old son are lifting it out with me manouvering whilst they pull the ropes! Never know with a bit of advise on here, parts and expertise from VP we might even get to sea this hols fingers crossed! ?

Cheers, Colin.
 
Gosh fair point. No pressure at all from the other box. I have not looked but Im guessing its cooled by the engine cooling water as opposed to raw water from the impeller/strainer?? In the morning we lift out the offending box and so will be taking off the water feed/return so perhaps some clues then.
I cannot help but be humble I have been told to get it all disconnected in the morning and lunchtime Wife/17 yr old daughter/10 yr old son are lifting it out with me manouvering whilst they pull the ropes! Never know with a bit of advise on here, parts and expertise from VP we might even get to sea this hols fingers crossed! ��

Cheers, Colin.

The MS4 is cooled by the raw water system. I suggest you turn off the sea cocks before disconnecting. You'll see the two water pipes coming down to the gearbox.

Although I'm not familiar with the internal coolant flow, the gearbox should only get warm in normal use, not hot, so when the gearbox is dismantled check the internals for scale, blockages or restrictions.

Good luck, and let us know how you get on and what you find.
 
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