Volvo Penta S120C Workshop Manual

[rclark]

I have 2 broken volvo penta s120c gearboxes. One that was in my boat has a worn clutch face that looks like the sliding sleeve needs replacing after I lost forward gear and a second-hand one that I bought that has worn propshaft bearings and wear on the propshaft where the seals have been rubbing. I am hoping to turn these into one working gearbox. Does anyone have any official guidance on clutch replacement and propshaft bearing replacement and shimming - a workshop manual would be a great help.

Thanks

[Ex-Calif]

Dang - I had one but now I can't find it. New computer recently. Gotta go research my archives.

Now I think I need one too...

[GordMay]

Greetings and welcome aboard the CF, rclark.

[jaybird1111]

Reviving an old thread:

am in search for same. If anyone has this manual, please get in touch with me. I have searched Google with every term I can think of. I have been searching the sailing forums, literally hundreds of posts, with no luck.

Thank you in advance

[DougR]

I have this manual.....publication #7752950
It covers the MS2 series of gears: down angle straight and V drives and the 120S saildrive, models A thru E.

84 pages.....
How can I help you?

DougR

[jaybird1111]

Originally Posted by DougR

I have this manual.....publication #7752950

That's the very one. Went to VP to order the hard copy; they won't ship until March of next year

I was hoping maybe someone had a digital copy/PDF or knew where the site to download same. Care to scan yours? I've a 120S saildrive, and I think the sliding sleeve is done, and I'm looking to replace it.

Any troubleshooting tips for symptom: unable to shift into fwd or reverse (grinding noises, won't engage the gear). Removed shifting cable and tried to shift by hand, same result.

Have seen another post here in regards sliding sleeve replacement with custom tool and will attempt to perform as per the directions in the thread.

[DougR]

I don't know if I have a PDF of the manual, I'll have to check my files. If not I think I can get one.....

VP has used the cone clutch in stern drives, inboard gears and saildrives for about 50 years, and usually the reason for the loss of shifting is that the cone surface and its mating "cup" become polished and slip when the operator tries to engage a gear. The surface of the cone has grooves machined into it, and these grooves allow the cone to displace the oil film and make contact with the cup. The torque of the engine then forces the cone and cup together even more and power is transmitted across the surface and to the propeller. The reason that the engine torque forces engagement is that the cone is riding on a vertical shaft, and the cone and shaft are machined with a helix or helical gear interface. The torque reaction of the helix is to force the cone and cup together...the more power applied, the higher the force pushing the two together.

Slipping can be caused by long hours of use, or hard high RPM shifting, or in the case of saildrives, by shifting into forward gear to lock the propeller while sailing.
The same helix on the cone that locks the cone and cup together while motoring will tend to separate the cone and cup while sailing if the shift lever is left if forward gear. The motion of the water across the propeller while sailing tends to rotate the vertical shaft with the rotational force coming up from the prop instead of from the engine and that makes the helix pull the cone away from the cup. So you have the shift linkage pushing the cone into engagement and the helix pulling the cone out of engagement and the result is the cone slips and wears out the machined grooves on the surface of the cone so it can no longer displace the oil film and engage.
The way to avoid this is to lock the propeller in reverse gear while sailing....then the helix and shift linkage are working together to keep things engaged.

Usually this slipping shows up on only on the forward gear, as this is the gear that receives the most use. Reverse gear should still work as the reverse side of the cone isn't worn. Also, normally if the cone is worn out there isn't excessive noise from the drive, it just slips and won't go into gear. This makes me suspect something else is causing your problem. Maybe the coupling between the upper vertical shaft and the lower vertical shaft has sheared. This would keep power from getting to the propshaft. Or maybe the shift shoe that moves the cone up and down is broken and it doesn't move the cone at all when you shift. Or maybe there is a problem with the input shaft to the saildrive, like stripped splines.....no noise in neutral, but grinding when prop load is applied after shifting. Some things to ponder.....

DougR

[jaybird1111]

Originally Posted by DougR

I don't know if I have a PDF of the manual, I'll have to check my files. If not I think I can get one.....

If you can get that PDF I'd be eternally grateful, or at the very least I'd like to offer something for your time.

Originally Posted by DougR

The way to avoid this is to lock the propeller in reverse gear while sailing....then the helix and shift linkage are working together to keep things engaged.

can't speak for PO(s) but i've always put into reverse under sail. Drives are 20YO, boat's first 10 years were in charter, who can say?

Originally Posted by DougR

Usually this slipping shows up on only on the forward gear, as this is the gear that receives the most use. Reverse gear should still work as the reverse side of the cone isn't worn. Also, normally if the cone is worn out there isn't excessive noise from the drive, it just slips and won't go into gear. This makes me suspect something else is causing your problem. Maybe the coupling between the upper vertical shaft and the lower vertical shaft has sheared. This would keep power from getting to the propshaft. Or maybe the shift shoe that moves the cone up and down is broken and it doesn't move the cone at all when you shift. Or maybe there is a problem with the input shaft to the saildrive, like stripped splines.....no noise in neutral, but grinding when prop load is applied after shifting. Some things to ponder.....

Hope this description is clearer: the thing wont go into gear AT ALL, fwd or reverse. What happens is analogous to trying to put a car transmission into gear without clutching - it just grinds, *as I'm trying to engage,* and won't engage, well I haven't tried to force it - goes quiet when I return to neutral. With or without the shift cable, so it's not that. Of your suggestions, I'm inclining towards the shift shoe possibility, if not the original guess (sliding sleeve).

Can't even get into gear to load the prop, it seems to me. That said, though, I am aware that the splines have some good wear as i noticed that when I replaced my boot recently.

Wife/helmsman has just reminded me that the drive has, for some time, 'paused' before going into gear. She would move the lever into gear of choice, there'd be a slight pause (slip?), then the gear engaged. No noise though. Before the failure, that is.

How the failure went down... Motored to anchorage. Put gears in neutral to allow boat to slow/stop head to wind. Dropped anchor and when she attempted to put into reverse, -grind-. Attempted fwd, -grind-

Again, thank you for your time

[DougR]

The pause before gear engagement is symptomatic of slipping cone...sometimes the cone will slip until the engine is revved up, then the cone engages with a smack.

However if the grinding is coming during the shift process, it does sound like something is amiss with the shift shoe. You can pull the shift assembly off the side of the drive by removing the four bolts and have a look. The shoe is spring loaded and rides in a machined groove in the shift cone on the inner end, and it and its spring sit in the cable actuated shift bellcrank on the outer end. You will notice that the shoe is not in the center of the shift bellcrank, but is located offset from the center. This makes the shoe move up and down when the bellcrank is moved by the shift cable. This offset also means that the shift shoe isn't symetrical where it rides in the cone and can it only be installed one way.

Go in and have a look......any damage should be fairly obvious.

What engine is attached to this drive?

DougR

[jaybird1111]

Originally Posted by DougR

What engine is attached to this drive?

First, thank you again for all the info and the quick reply.

Our engines are MD2030D


I pulled the shift shoe assembly and found the shoe itself to be in fair condition but I did note the assembly was installed 180' out from the diagrammed position. This appears to be a workaround for improper installation of the shift control cable at the helm station.

Also, I spotted a big crack in the housing which supports the shoe. The crack is in the root of the stop pin forward. See attached pictures:






The crack doesn't appear to have any effect on the shifting operation, but it certainly doesn't look good. I was able to acquire a couple 120 saildrive assemblies, as it happens, and pulled a 'good' shift assembly from one of them to try in the boat. This made no difference in the ability to engage. The cone seems to engage forward and reverse.

I was able to watch the upper shaft and bearing rotate with the engine running (oil cap off). The grinding sound is mild at idle and the shafts appear to rotate normally. As throttle is increased, the grinding sound gets much louder and it appears that the shaft is not spinning any faster (as best I can tell).

I am thinking at this point that it is indeed the splines.

Do you have any advice for separating the engine from the transmission with boat in the water? We do have about 6 inches that I can move the engine forward, should allow room to pull the input shaft and inspect the splines.

I have spotted a couple of options for spline conversion, UK based companies. Converts spline to hex.

Your thoughts and help are most appreciated. Let me know if there is any way I can repay your kindness.

[NoTies]

PM me an email address, I'll send a PDF.

[jaybird1111]

Originally Posted by NoTies

PM me an email address, I'll send a PDF.

Really appreciate this. Check your PM. thanks

[DougR]

The first thing when seperating the engine and drive whle the boat is in the water is to be careful......

The drive is connected to the flywheel housing coverplate with six bolts, three on each side. On each side of the drive mounting flange there is a blind hole about 12w mm in diameter. Make up two dowels or pins to fit into these holes snugly and extend maybe 4 inches to the side. Then measure from the pin to the saildrive fiberglas bed and make up two blocks to fit between the pin and the bed. These blocks will support the front of the drive when the engine is slid forward.

Remove all the other connecting stuff on the engine and slide it forward, supporting it with a 2x4 or plywood. Now you can see the input shaft spline and also the splines in the damper plate on the flywheel.

If the damper splines are shot, I can help you with a new one. If the shaft is shot, it means a new shaft and upper gear set, as they are a matched set. The on-line repair kits look interesting, but I have no experience with them.

If the splines look good, and the damper is tight on the flywheel then its something deeper and the saildrive is probably going to need to come out and be opened up.

If you end up changing the shifter to a better one, be sure you shim the shift shoe as described in the shop manual. Not doing so might make it difficult to get the drive back out of gear.

Did you get the manual from "no ties"?

DougR

[DougR]

Read a little more about the spline repair kits offered in the UK.....

These are for the 2000 series VP engines, not the 2030.

Early 2000 series engines had the splined input shaft, just like yours, but they didnt have a rubber torsional element on the flywheel. Instead they just had a steel splined hub bolted to the flywheel. This steel hub didnt absorb any torsionals, and the resulting fretting action took the splines off the shaft after awhile.

Later model 2000 series used a rubber element to eliminate the problem and extend the life greatly. All the engine series since then have had a single stage (2030) or two stage (D1-30) element on the flywheel.

Rgds,
DougR

[jaybird1111]

Thanks for the advice. Most appreciated. I'll give a shot at separating the engine from the transmission to check the splines and report back.

Still working on trying to get a copy of the manual - have not been sent one yet.

Thanks again