Volvo Penta · Saildrive

Volvo Penta 120S

The 120S family is the aluminium saildrive Volvo Penta paired with its small sailing-yacht diesels of the 1980s and 1990s: the original 120S behind the MD11C/D and MD17C/D, the 120S-B and S120C behind the 2001, 2002 and 2003, the 120S-D behind the MD2010–MD2040 and the 120S-E behind the MD22 and later MD2010–MD2040. It replaced the 110S and was followed by the MS25S and then the 130S. The leg has its own oil sump (2.2 l on the original 120S, about 2.8 l on the later versions), a ring anode behind the propeller and a rubber diaphragm sealing it to the hull, which Volvo Penta wanted renewed every five years in the MD11/MD17 book and every seven years in the later ones. Anode, drain plug, dipstick and shaft seals differ between the original 120S and the later versions, so read the designation and product number off the drive’s ID plate before ordering parts.

Manuals & documents
Wear parts & part numbers
Service intervals
Specifications
Good to know
Videos & how-tos
On the marketplace

Manuals & documents

The links go straight to Volvo Penta. We host no manuals or drawings — the manufacturer’s copy is the current one.

Operator’s manual MD2010–MD2040, 1998 edition (includes the 120S-E saildrive) Operation manual pubs.volvopenta.com · PDF · EN
Owner’s manual MD2010–MD2040, 1993 edition (includes the 120S-D saildrive) Operation manual pubs.volvopenta.com · PDF · EN
Instruction book MD22L, MD22, TDM22, 1995 (120S-E saildrive data) Operation manual pubs.volvopenta.com · PDF · EN
Instruction book 22 Series (MD22L/120S, TMD22P), 1998 (120S-E data) Operation manual pubs.volvopenta.com · PDF · EN
Instruction book 3000 Diesel series MD11, MD17/MS2, 120S (the original 120S) Operation manual pubs.volvopenta.com · PDF · EN · DE · FR · ES · IT · SV
Operator’s manual MD2010–MD2040 with the MS25S/MS25SR saildrive, 2002 (successor) Operation manual pubs.volvopenta.com · PDF · EN
Operator’s manual MD11C/110S and MD17C/110S (predecessor 110S) Operation manual pubs.volvopenta.com · PDF · EN
Workshop manual 120S, MS2 (printed, from Volvo Penta’s order service) Printed manual (to order) volvopenta.mis.elanders.com · EN
Product bulletin MD11D (MD11D/120S) Product leaflet pubs.volvopenta.com · PDF · EN
Product bulletin MD17D (MD17D/120S) Product leaflet pubs.volvopenta.com · PDF · EN
Product bulletin 2001 (2001S with the 120B drive), 1988 Product leaflet pubs.volvopenta.com · PDF · EN
Product bulletin 2003 (2003S with the 120B drive), 1988 Product leaflet pubs.volvopenta.com · PDF · EN
Volvo Penta manuals & handbooks: 120S (sister pages exist for 120S-B, 120S-D and 120S-E) Manual portal volvopenta.com · EN
Volvo Penta parts catalogue, filtered to 120S Parts catalogue volvopenta.com · EN
Parts catalogue: lower gear unit of the original 120S (MD11/MD17) Parts catalogue volvopenta.com · EN
Parts catalogue: lower gear unit 120S-D Parts catalogue volvopenta.com · EN
Parts catalogue: repair kits 120S-D/120S-E (gasket kit 876391, mounting kit 3856597) Parts catalogue volvopenta.com · EN
Parts catalogue: repair kits 120S-B/S120C (gasket kit 876391, sealing kit 854934) Parts catalogue volvopenta.com · EN

Wear parts & part numbers

Part	OEM number	Also fits	Note
Ring anode	`851983`^2,3,1,4	MG Duff `CM851983Z`¹	Zinc ring of the original 120S behind the MD11C/D and MD17C/D, as Volvo Penta’s parts catalogue lists it, fixed with two M6 screws 949823. Dealers sell 851983 and 876286 as interchangeable for every 120 version and the MS25S, either as a one-piece ring (propeller off to fit) or as a split ring with adapter plates that goes on with the propeller in place – check which form you are buying.
Ring anode	`876286`^5,6,7,8,1	—	Zinc ring kit for salt water. Volvo Penta’s catalogue lists it for the 120S-D, 120S-E and MS25S and for the 2001, 2002 and 2003 engines, whose drive is the 120S-B/S120C; two M6 screws 949823. Dealer dimensions: 97 mm outer diameter (122 mm over the lugs), 40 mm bore, 72 mm between the bolt holes, 27 mm high.
Ring anode	`23973978`^5,6,9	—	Aluminium version of the ring for salt and brackish water, listed for the same drives as 876286; not supplied with a new lower gear.
Ring anode	`876604`^5,10,11	—	Magnesium ring for fresh water only – Volvo Penta: zinc in salt water, magnesium in fresh water. Listed for the same drives as 876286; an anode maker gives 0.13 kg and the same dimensions as the zinc ring.
Propeller anode	`852018`^{12,13,14,15,16}	—	Pair of small zinc anodes screwed to the hub of Volvo Penta’s older 2-blade folding propellers (851062 14×8, 851063 15×9, 852098, 852099 17×13, 853814 17×15) on the 110S, 120S and 120S-B/S120C; Volvo’s catalogue lists the kit with each of these propellers.
Propeller anode	`853430`^13,17,18	—	Magnesium version of 852018 for fresh water, with two magnesium anodes; listed with the folding propellers of the 2001, 2002 and 2003 (120S-B/S120C).
Propeller anode	`3858399` · `23974203` · `3858400`^19,20,21,22	—	Shaft anode of Volvo Penta’s later folding propellers – the 2-blade hub kit 3858849 and the 3-blade S-drive hub kit 3858955, which Volvo lists for the 110S, 120S, MS25S, 130S and 150S: 3858399 zinc, 23974203 aluminium, 3858400 magnesium, each fixed with three screws 963677.
Saildrive diaphragm	`21389074`^{2,23,24,25,26,27}	—	Rubber bellows kit sealing the drive to the hull. Volvo Penta’s catalogue lists it for the 110S, the original 120S, the 2001–2003 engines (120S-B/S120C), the MS25S and the 130S/150S; its 120S-D and 120S-E pages do not show the hull seal at all. Contents per the MS25S-A repair-kit page: bellows 3875251, cover plate 21506667, O-ring 960238 and sealing-ring kits 21112496 and 21112497. Volvo Penta wants it renewed every seven years (every five in the MD11/MD17 book), a job for an authorised workshop.
Hull rubber protector	`22303438`^28,5,7,29,30	—	Rubber cover bonded to the hull around the leg (“mounting kit”, “cover plate drive unit 120SB, S120C” in Volvo’s catalogue), shown on the 120S-B/S120C, 120S-D, 120S-E and MS25S pages. Dealer: 317 × 237 mm; Volvo Penta now supplies the 130S/150S cover 21506667 instead (335 × 250 mm, drain hole elsewhere), and that is the cover in diaphragm kit 21389074.
Propeller shaft seal	`851979`^2,31,28,32	—	Propeller-shaft oil seal of the original 120S and the 120S-B/S120C, two needed; also in gasket kits 875720 (120S) and 876391 (120S-B/S120C).
Propeller shaft seal	`873108`^5,33,34,35	—	Propeller-shaft oil seal of the 120S-D and 120S-E, two needed. Volvo Penta marks it “included in gasket kit”, and the current contents of that kit 876391 list two sealing rings 3593663 instead – the shaft seal of the MS25S and 130S.
Gasket set	`876391`^34,28,36	—	Gasket kit for the 120S-B/S120C, 120S-D and 120S-E (also listed for the MD2010–MD2040 C/D and MD22): the O-rings, gaskets and shaft seals of the upper and lower gear, some items marked “not for 120S-E”. Volvo’s 120S-B/S120C page still shows the older contents with the 851979 shaft seals.
Gasket set	`875720`^31,37,38	—	Gasket and locking kit for the original 120S (MD11C/D, MD17C/D), with the two 851979 shaft seals and the drive’s O-rings and gaskets.
Installation kit	`3856597`^34,39,40	—	Mounting kit for refitting a 120S-D or 120S-E (also listed for the MD2010–MD2040 C/D and MD22): sealing strip, gasket 3856834, O-ring 925256, locking wire 852669 and 60 g of sealant 1141570. It replaces 854934 on the 120S-D/-E pages.
Installation kit	`854934`^28,41,42	—	Sealing kit for the 120S-B, S120C and the 120S-E behind the MD22: sealing strip, gasket, O-ring 925256, locking wire 852669, sealant 1141570 and the hull cover 22303438.
Drain plug	`852904`^{5,6,7,43,44,45}	—	Magnetic oil drain plug in the propeller gear housing of the 120S-D, 120S-E and MS25S and of the 2001–2003 installations (120S-B/S120C), earlier number 839354. Torque 10 ± 5 Nm in the MD2010–MD2040 manuals, 20 ± 5 Nm in the MD22 book.
Drain plug gasket	`955974`^5,6,46,44	—	O-ring of the magnetic drain plug 852904 (15.1 mm outside diameter); Volvo Penta says check it at every oil change and renew it if damaged.
Drain plug	`804262`^2,47	—	Oil drain plug of the original 120S lower gear (MD11/MD17), sealed with gasket 804261.
Drain plug gasket	`804261`^2,31,48	—	Sealing washer for drain plug 804262 on the original 120S; also in gasket kits 875720 and 876391.
Dipstick	`873087`^39,49,50,44	—	Dipstick of the 120S-D and 120S-E, sealed with O-ring 925055. Read it resting on the thread, not screwed in.
Dipstick	`852314`^51,52	—	Dipstick of the original 120S and the 120S-B/S120C, 157 mm long, with O-ring 925054.
Oil filler plug	`851754`^51,39,49,53	—	Oil filler cap on the upper gear, the same part on every 120S version.
Gear oil	`1141572`^45,54	—	Volvo Penta transmission oil API GL5 SAE 75W-90 synthetic, specified as 1141572-6 for the 120S-E in the MD22 instruction book. The MD2010–MD2040 manuals specify engine oil API CD SAE 15W-40 for the 120S-D/-E instead — find out which oil is in your drive before topping up and never mix them.
Propeller shaft grease	`828250`^55,45,27,56	—	Water-resistant grease (pad 828250-1) for the shaft, hub, blade teeth and pins of folding propellers, and for the shaft at lay-up.
Primer & antifouling for the drive	`1141593` · `1141594`^{55,45,27,57,58}	—	1141593-2 primer and 1141594-0 antifouling, the products the 1993 and 1995 books name for the S-drive; for the original 120S the MD11/MD17 book names touch-up paint 1141567-6. Never copper-oxide antifouling on the aluminium drive.
Propeller nut	`872326`^59,60,61	—	Propeller nut of Volvo Penta’s 2-blade folding propellers 872599–872602 (later 3858507–3858512), with set screw 872327; listed for the 2001–2003 (120S-B/S120C) and the MD2010–MD2040 A/B and MD22 (120S-D/-E).
Propeller nut	`852044`^12,13,62	—	Castle nut, with split pin 949807, of the older 2-blade folding propellers (851062, 851063, 852098, 852099, 853814) on the 110S, 120S and 120S-B/S120C.
Propeller	`3858955`^19,21	—	Hub kit for Volvo Penta’s 3-blade folding propeller (20–60 hp) in the S-drive version; Volvo names the 110S, 120S, MS25S, 130S and 150S. The blades come separately as left- or right-hand kits from 14×7 to 19×16; the hub kit includes nut 3584466, lock washer 3851994 and the zinc shaft anode 3858399.
Propeller	`839514` · `839191`^63,64,65	—	Volvo Penta 2-blade fixed propellers 14×8 (839514) and 16×11 (839191), which Volvo lists for the S-drives 50S, 100S, 110S, 120S, MS25S, 130S and 150S.

Numbers checked against the sources below on 23 October 2026. Always confirm against your serial number and exact type before ordering.

Service intervals

Task	Interval
Oil level check	Every 14 days, with the dipstick resting on the thread, not screwed in^44,55,66
Drive oil change	Every 200 h or at least yearly, and before winter lay-up^44,55,66
Anode	Check every 200 h or yearly (every 100 h or yearly in the 22 Series book for the MD22); replace at 50 % wear or at least once a season^44,55,66
Rubber seal (drive to hull)	Check every 200 h or yearly and at lay-up; replace every 7 years, earlier if damaged (authorised workshop). The MD11/MD17 book for the original 120S says every 5 years^44,55,66,27
Propeller	Folding propeller: dismantle, clean and grease yearly; new tab washer and locking screw every 4 years^44,66
Winterising	At every lay-up and launch: touch up paint damage and renew the antifouling — the paint is part of the corrosion protection⁴⁴
Season check	At launch: check the drive oil level, replace the anode if less than half is left and rub it bright with emery cloth just before launching, refit the propeller, then check for leaks^44,55

Hours or time, whichever comes first, from the 1998 operator’s manual MD2010–MD2040 (120S-E); the 1993 book (120S-D) gives the same oil, anode and seal intervals. The 22 Series book for the MD22 wants the anode and rubber seal checked every 100 h or yearly, and the MD11/MD17 book for the original 120S a new rubber seal every 5 years. The books differ on oil grade, capacity, ratio and drain-plug torque (see specifications).

Specifications

Type	Aluminium saildrive bolted straight to the engine; engine and drive sit on a three-point flexible mounting on a GRP bed and are sealed to the hull by a rubber diaphragm. Own oil sump, zinc ring anode and cooling-water intake in the leg^67,68,44,55
Versions	120S (MD11C/D, MD17C/D), 120S-B and S120C (2001, 2002, 2003), 120S-D (MD2010–MD2040, 1993 book), 120S-E (MD22 books of 1995 and 1998, MD2010–MD2040 book of 1998). The drive’s ID plate gives designation, serial number, product number and gear ratio^{69,37,28,70,41,27,55,44,45,66}
Predecessor	110S, ratio 1.66:1, behind the MD5A, MD11C, MD17C and MD21B among others; it has its own ring anode (875812 zinc, 876603 magnesium) and gasket kit 875591^71,72,73,74
Successor	MS25S/MS25SR behind the MD2010–MD2040 C/D: 2.19:1 or 2.47:1, about 2.0 l of API CD SAE 15W-40, 28 kg (2002 manual). It shares the zinc ring 876286, drain plug 852904, diaphragm kit 21389074 and shaft seal 3593663 with the later 120S. Then the 130S: Volvo Penta’s catalogue now replaces the MS25S drive units with 130S drives (3584506, 3584508)^{75,76,7,24,77,78}
Gear ratio	2.20:1 on the original 120S (MD11/MD17) and 2.2:1 on the 120S-B (2001–2003); 2.48:1 behind the MD2010–MD2040 (120S-D and 120S-E, listed as 2.5:1 in the parts catalogue); 2.2:1 for the 120S-E behind the MD22^{27,68,44,45,70}
Drive oil	Three official values: the original 120S (MD11/MD17 book) takes the same oil as the engine, API CD (SAE 15W-40 above +10 °C); the MD2010–MD2040 manuals (120S-D 1993, 120S-E 1998) specify engine oil API CD SAE 15W-40; the MD22 books (120S-E, 1995 and 1998) specify Volvo Penta transmission oil 1141572-6, API GL5 SAE 75W-90 synthetic. Follow the manual for your own engine/drive combination^{27,55,44,45,66}
Drive oil capacity	approx. 2.8 l (120S-D, 120S-E), with only 0.07 l between MIN and MAX on the dipstick, so top up in small amounts; 2.2 l on the original 120S^44,55,66,27
Drain plug torque	10 ± 5 Nm (MD2010–MD2040 manuals); 20 ± 5 Nm (MD22 instruction book)^55,45
Tightening torques	Folding propeller nut 65–75 Nm with a 24 mm socket (1993 book) or 70 Nm (1998 books); tab-washer locking screw 20 Nm; blade-pin locking screws 20 Nm with thread sealant, 4 mm hex key^55,44,66
Weight	28 kg^44,55,66
Material	Aluminium drive; anodes zinc in salt water, magnesium in fresh water — never painted^44,55
Cooling	Raw cooling water is drawn in through the drive leg, which has its own sea cock; on the 120S-D the hose to the engine’s seawater pump is 943369 (1000 mm, 1150 mm on the MD2040)^44,67,70,79
Propeller	Volvo Penta 2-blade folding propellers from 14×8 to 17×15, the 3-blade folding propeller (S-drive hub kit 3858955, blades 14×7 to 19×16) or 2-blade fixed propellers 14×8 and 16×11^{12,17,59,19,63}

Good to know

Volvo Penta’s own books disagree on the drive oil: the MD11/MD17 book has the original 120S run on the engine’s oil, the MD2010–MD2040 manuals say engine oil API CD 15W-40, the MD22 books say GL5 75W-90 synthetic for the 120S-E. Go by the manual for your own engine and drive version, check what is in the drive now, and never mix the two.^27,45,44,66
Grey or milky drive oil means water has got in. Stop using the drive and have the seals checked by a workshop before running it again.⁴⁴
Read the oil level with the dipstick resting on the thread, not screwed in. Only 0.07 l separate MIN and MAX, so overfilling is easy — drain any excess.⁵⁵
Rub the anode bright with emery cloth just before launching — never a wire brush or steel tools, and never paint it; leave about 10 mm around it free of antifouling. On and near the aluminium drive use only copper-free or copper-thiocyanate antifouling; copper-oxide and tin-based paints cause galvanic damage.⁵⁵
Take the folding propeller off for winter storage and grease the shaft. Fit a new tab washer and locking screw every four years, and only a Volvo Penta original locking screw.⁴⁴
Volvo Penta’s interval for the rubber diaphragm grew from five years (MD11/MD17 book, original 120S) to seven (1993 and 1998 books), and earlier still if it is cracked – age counts, not hours. Keep the invoice for the change, since insurance surveyors ask for proof, and never aim a pressure washer at the propeller shaft seal or the diaphragm.^27,55,44,26

Videos & how-tos

Links to YouTube, nothing embedded. The maker’s own channel comes first; the rest are channels we found clear and correct for this model.

Replacing the 120S diaphragm behind an MD2020, step by step Video Refit and Sail · EN · 49 min
Replacing the anode on a 120S Video Beryl Mary Travels · EN · 6 min
Replacing the shaft seals on a 120S behind a 2003 (German) Video Sebastian Otten · DE · 7 min
Refitting a 120S: corrosion protection, new hull seal and torques Video youngbarnacles · EN · 17 min

On the marketplace

Browse the category on boatparts.app

Looking for a part for the Volvo Penta 120S? Post a wanted ad in the app — it is free, it sits on the live map, and boaters nearby who have the part aboard can answer.

Got spares you no longer need? List them in a minute. No commission, ever.

Get the app

Sources

Volvo Penta is a trademark of its owner; boatparts.app is not affiliated with it. Part numbers are quoted for identification only. Spotted an error? Write to mail@boatparts.app.