I have a 1987 E28 and I'm trying to change the impeller on the Universal M12 engine. I've taken the cover plate off and pulled the impeller but the shaft came out with it. There seems to be a retaining clip on the end of the shaft. Nothing I've seen or read talks about this. Does anyone know how to get the 2 pieces apart or know of the tool I use to do so. Thanks Phil S.
Impeller Shaft Issue
- Thread starter Phil
- Start date
Sounds like the Oberdorfer pump on our '88 23hp Universal. I have never found a good way to remove the impeller and leave the shaft in place, even tho conventional wisdom is to do that.
I slide out the shaft with the impeller. Impeller is removed with a little cir-clip removal plier. It's tricky, and try not to lose the little spring clip or break it.
Be careful when re-inserting the shaft - be gentle. You do not want to nick the invisible inner seal that divides the water from the engine oil. (!)
There are probably some videos of the process, on the 'net somewhere too.
Regards,
Loren
I slide out the shaft with the impeller. Impeller is removed with a little cir-clip removal plier. It's tricky, and try not to lose the little spring clip or break it.
Be careful when re-inserting the shaft - be gentle. You do not want to nick the invisible inner seal that divides the water from the engine oil. (!)
There are probably some videos of the process, on the 'net somewhere too.
Regards,
Loren
Alan Gomes
Sustaining Partner
The circ-clip is unnecessary. Remove it and just toss it. If you stop and think about it, there's no way for the impeller to come forward off the shaft when it's installed in the pump with the cover plate fastened. It's most likely there so that when a new pump is shipped and not yet installed the shaft will not pull out through the back of the pump. At least that would be my best guess because there is no reason for it otherwise. I've had two Universal engines with Oberdorfer pumps and never needed that clip.
Agreed, though, about the need to be careful when re-inserting the shaft.
Rocinante33
Contributing Partner
Remove the circlip first. Before removing the impeller, put the tip of a screwdriver against the end of the shaft. Then pull the blades of the impeller towards you using needlenosed pliers. As long as the impeller blades are not too rotten, the body of the impeller should slide off the shaft and dangle on your screwdriver blade for removal. This way you can hold the shaft in place with the screwdriver and you do not remove it.
stgermain45
Member I
Impeller Change Instructions
Hi Phil,
You probably know this already and are now done with the impeller change and onto the next fun boat project...but your sea water pump is a Sherwood, not Oberdorfer. An easy way to tell the difference - Sherwood has 6 screws on the cover, Oberdorfer has 4. I left several impeller change kits on the boat (Sherwood 10077K - same as Universal 287439) and an impeller puller.
Below are instructions from marinedieseldirect.com, hope it helps!
SEA WATER PUMP:
Your engine is equipped with a rubber impeller type sea water pump.
CAUTION: DO NOT RUN PUMP DRY AT ANY TIME OR YOU WILL DAMAGE THE IMPELLER, CAUSING ENGINE TO OVERHEAT.
You can use methyl alcohol based anti-freeze compounds such as Zerex, Shell Zone, Pyro Permanent, Permagard and Dowgard.
REPLACEMENT OF SEA WATER PUMP IMPELLER:
1. Be sure engine is stopped. Turn off sea water inlet valve.
2. Loosen and remove the pump cover screws.
3. Tap cover on side to loosen, being careful not to damage cover gasket and remove cover.
4. At this time be careful not to pull the pump shaft forward or Out of its present position. If the shaft does come forward during the changing of impeller, it will be necessary to remove complete pump.
5. Remove the snap ring located on the end of shaft in center of impeller, with shaft held in place.
6. The impeller can now be pulled off the pump shaft. Be sure to hold shaft in place with a screwdriver or etc., when removing the impeller.
7. Replace with the new impeller by rotating. (You can lubricate impeller with Vaseline or oil prior to installing.) This will also prevent burning of new impeller when first starting engine.
8. Replace snap ring, being sure it is in the groove all the way around.
9. Replace gasket and cover (oil inside of cover).
10. Replace the cover screws and tighten evenly.
11. Open sea water inlet valve, check for leaks.
12. Engine can now be started, check engine temperature.
NOTE: IF DURING IMPELLER REPLACEMENT THE PUMP SHAFT CAME FORWARD, IT COULD HAVE COME OUT OF THE GROOVE AND DRIVE ADAPTOR. IF SO, YOU MUST COMPLETE THE FOLLOWING. NOTE - ON NEWER UNITS WITHOUT A MOUNTING SPACER BETWEEN THE PUMP AND ENGINE BLOCK YOU DO NOT HAVE A DRIVE ADAPTOR TO BE CONCERNED ABOUT. HOWEVER, YOU MUST ALIGN THE SHAFT TANG AND THE DRIVE
GROOVE WHEN REINSTALLING THE PROPELLER SHAFT.
1. Loosen and remove the two capscrews holding the pump body to engine.
2. Slowly move pump away from engine as the adaptor will come out.
3. Complete the replacement of impeller as noted above.
4. The pump shaft will now be protruding through the body mounting flange.
5. - Place the adaptor on to the pump shaft aligning the pin on the groove. On later models this may not be present, the pump may mount direct to engine block.
6. Align the slot on the other side of adaptor with the drive shaft in engine and place pump on engine.
7. Hold in place and start the two mounting capscrews. TIGHTEN FINGER TIGHT SO PUMP IS FREE TO MOVE AND ALIGN ITSELF. ON 1987 MODELS THE PUMP HAS A PILOT FOR SELF ALIGNING, JUST MOUNT AND TIGHTEN.
8. Open sea water valve and start engine at idle. This will align pump to the drive and adaptor.
9. Stop engine - now tighten capscrews carefully.
CAUTION: BE VERY CAREFUL DUE TO V-BELT MOVING ON FRONT OF ENGINE.
10. Feel the bearings to make sure they are not hot; they are located in the center of pump body.
11. Alignment of pump can also be accomplished by turning engine over with the starter while decompression lever is in the open position, approximately 5 to 10 revolutions. Release starter button and decompression lever - tighten water pump screws.
NOTE: THERE ARE TWO TYPES OF SEA WATER-RUBBER IMPELLER PUMPS USED. ORBERDORFER PUMP HAS 4 SCREWS SECURING COVER TO PUMP BODY AND SHERWOOD PUMP WHICH HAS 6 SCREWS SECURING COVER TO PUMP BODY. NOTE WHICH PUMP YOU HAVE ON COVER OF THIS MANUAL. IT IS RECOMMENDED TO HAVE A SPARE IMPELLER AND COVER GASKET ON BOARD AT ALL TIMES.
ORBERDORFER IMPELLER NO. 295628
COVER GASKET NO. 295626
SHERWOOD IMPELLER NO. 287439
COVER GASKET NO. 295745
CAUTION: DO NOT RUN PUMPS DRY OR WITH SEA INLET VALVE CLOSED. LACK OF WATER WILL CAUSE EXCESSIVE HEAT BUILD UP DAMAGING OR DESTROYING THE RUBBER IMPELLER, AND ENGINE WILL OVERHEAT.
IF VANES COME OFF IMPELLER THEY MUST BE LOCATED AND REMOVED TO INSURE THEY ARE NOT BLOCKING OR RESTRICTING THE COOLING WATER FLOW IN THE ENGINE, HOSES, OR FITTINGS.
NEW STYLE PUMPS HAVE A PILOT AND CAN BE MOUNTED AND BOLTED TIGHT WITHOUT TURNING THE ENGINE OVER.
Hi Phil,
You probably know this already and are now done with the impeller change and onto the next fun boat project...but your sea water pump is a Sherwood, not Oberdorfer. An easy way to tell the difference - Sherwood has 6 screws on the cover, Oberdorfer has 4. I left several impeller change kits on the boat (Sherwood 10077K - same as Universal 287439) and an impeller puller.
Below are instructions from marinedieseldirect.com, hope it helps!
SEA WATER PUMP:
Your engine is equipped with a rubber impeller type sea water pump.
CAUTION: DO NOT RUN PUMP DRY AT ANY TIME OR YOU WILL DAMAGE THE IMPELLER, CAUSING ENGINE TO OVERHEAT.
You can use methyl alcohol based anti-freeze compounds such as Zerex, Shell Zone, Pyro Permanent, Permagard and Dowgard.
REPLACEMENT OF SEA WATER PUMP IMPELLER:
1. Be sure engine is stopped. Turn off sea water inlet valve.
2. Loosen and remove the pump cover screws.
3. Tap cover on side to loosen, being careful not to damage cover gasket and remove cover.
4. At this time be careful not to pull the pump shaft forward or Out of its present position. If the shaft does come forward during the changing of impeller, it will be necessary to remove complete pump.
5. Remove the snap ring located on the end of shaft in center of impeller, with shaft held in place.
6. The impeller can now be pulled off the pump shaft. Be sure to hold shaft in place with a screwdriver or etc., when removing the impeller.
7. Replace with the new impeller by rotating. (You can lubricate impeller with Vaseline or oil prior to installing.) This will also prevent burning of new impeller when first starting engine.
8. Replace snap ring, being sure it is in the groove all the way around.
9. Replace gasket and cover (oil inside of cover).
10. Replace the cover screws and tighten evenly.
11. Open sea water inlet valve, check for leaks.
12. Engine can now be started, check engine temperature.
NOTE: IF DURING IMPELLER REPLACEMENT THE PUMP SHAFT CAME FORWARD, IT COULD HAVE COME OUT OF THE GROOVE AND DRIVE ADAPTOR. IF SO, YOU MUST COMPLETE THE FOLLOWING. NOTE - ON NEWER UNITS WITHOUT A MOUNTING SPACER BETWEEN THE PUMP AND ENGINE BLOCK YOU DO NOT HAVE A DRIVE ADAPTOR TO BE CONCERNED ABOUT. HOWEVER, YOU MUST ALIGN THE SHAFT TANG AND THE DRIVE
GROOVE WHEN REINSTALLING THE PROPELLER SHAFT.
1. Loosen and remove the two capscrews holding the pump body to engine.
2. Slowly move pump away from engine as the adaptor will come out.
3. Complete the replacement of impeller as noted above.
4. The pump shaft will now be protruding through the body mounting flange.
5. - Place the adaptor on to the pump shaft aligning the pin on the groove. On later models this may not be present, the pump may mount direct to engine block.
6. Align the slot on the other side of adaptor with the drive shaft in engine and place pump on engine.
7. Hold in place and start the two mounting capscrews. TIGHTEN FINGER TIGHT SO PUMP IS FREE TO MOVE AND ALIGN ITSELF. ON 1987 MODELS THE PUMP HAS A PILOT FOR SELF ALIGNING, JUST MOUNT AND TIGHTEN.
8. Open sea water valve and start engine at idle. This will align pump to the drive and adaptor.
9. Stop engine - now tighten capscrews carefully.
CAUTION: BE VERY CAREFUL DUE TO V-BELT MOVING ON FRONT OF ENGINE.
10. Feel the bearings to make sure they are not hot; they are located in the center of pump body.
11. Alignment of pump can also be accomplished by turning engine over with the starter while decompression lever is in the open position, approximately 5 to 10 revolutions. Release starter button and decompression lever - tighten water pump screws.
NOTE: THERE ARE TWO TYPES OF SEA WATER-RUBBER IMPELLER PUMPS USED. ORBERDORFER PUMP HAS 4 SCREWS SECURING COVER TO PUMP BODY AND SHERWOOD PUMP WHICH HAS 6 SCREWS SECURING COVER TO PUMP BODY. NOTE WHICH PUMP YOU HAVE ON COVER OF THIS MANUAL. IT IS RECOMMENDED TO HAVE A SPARE IMPELLER AND COVER GASKET ON BOARD AT ALL TIMES.
ORBERDORFER IMPELLER NO. 295628
COVER GASKET NO. 295626
SHERWOOD IMPELLER NO. 287439
COVER GASKET NO. 295745
CAUTION: DO NOT RUN PUMPS DRY OR WITH SEA INLET VALVE CLOSED. LACK OF WATER WILL CAUSE EXCESSIVE HEAT BUILD UP DAMAGING OR DESTROYING THE RUBBER IMPELLER, AND ENGINE WILL OVERHEAT.
IF VANES COME OFF IMPELLER THEY MUST BE LOCATED AND REMOVED TO INSURE THEY ARE NOT BLOCKING OR RESTRICTING THE COOLING WATER FLOW IN THE ENGINE, HOSES, OR FITTINGS.
NEW STYLE PUMPS HAVE A PILOT AND CAN BE MOUNTED AND BOLTED TIGHT WITHOUT TURNING THE ENGINE OVER.
Impeller shaft issues still!
Well here's the deal. I found the parts you left on the boat for the impeller. I've changed the impeller but did pull the shaft out at that time. It seamed to go back in just fine. After doing so and putting it back together I ran the motor for about 2 minutes. I didn't have any exhaust water so I shut it down. I have been reading some troubleshooting scenarios and will start checking these out this weekend.
Thanks
Phil
ps: Is the retaining clip necessary on the Sherwood pump because now I can't get it back on!
Well here's the deal. I found the parts you left on the boat for the impeller. I've changed the impeller but did pull the shaft out at that time. It seamed to go back in just fine. After doing so and putting it back together I ran the motor for about 2 minutes. I didn't have any exhaust water so I shut it down. I have been reading some troubleshooting scenarios and will start checking these out this weekend.
Thanks
Phil
ps: Is the retaining clip necessary on the Sherwood pump because now I can't get it back on!
stgermain45
Member I
Hi Phil,
You did remember to open the seawater intake thru-hull before starting the engine, right?
I can't debunk what others have said about not needing the circlip, but I would replace/reuse it if it were me. Do you happen to have a copy of Nigel Calder's "Boatowner's Mechanical and Electrical Manual"? If not, I HIGHLY recommend buying the book. It goes into detail regarding impeller replacement with troubleshooting and exploded parts diagrams.
Best of luck,
Chris
You did remember to open the seawater intake thru-hull before starting the engine, right?
I can't debunk what others have said about not needing the circlip, but I would replace/reuse it if it were me. Do you happen to have a copy of Nigel Calder's "Boatowner's Mechanical and Electrical Manual"? If not, I HIGHLY recommend buying the book. It goes into detail regarding impeller replacement with troubleshooting and exploded parts diagrams.
Best of luck,
Chris
. Just bought Calder's book. I've been reading some more trouble shooting post and am going to check it out today.O'Neil Dillon
New Member
circlip neededk or not?
What is the consensus on wether the circlip on the Oberdorfer pump is needed or not? Is there any engineering reason for it when the pump is all together and operational? In that setting, the only thing I can figure the clip does is not allow the shaft to move in toward the engine. I have left mine off for the last 400 hours and noted no problems. It sure is a lot easier to change out an impeller without that little bugger.
What is the consensus on wether the circlip on the Oberdorfer pump is needed or not? Is there any engineering reason for it when the pump is all together and operational? In that setting, the only thing I can figure the clip does is not allow the shaft to move in toward the engine. I have left mine off for the last 400 hours and noted no problems. It sure is a lot easier to change out an impeller without that little bugger.
Second Star
Member III
One other reason for the pump not working after replacing the impeller is that the tiny shaft key is not in place (shaped like a half moon) and the shaft just spins inside the impeller. It falls out when you pull the old impeller and is very hard to see. If you did not see it fall you might reasonably assume there is not one; no instructions I've seen talk about the miserable job of putting it back in and that it is almost impossible without pulling the shaft out at least 1 inch. If you didn't put one back in, have a look in the area under the pump (good luck).
oneil dillon
New Member
The Oberdorfer pump I am replacing is on a Universal 5432 Diesel and is an N202M-15. The shaft does not use a key, but has a flat spot on it to lock the impeller in place. I am referring to the circlip at the end of the shaft. This would hold the impeller on the end of the shaft if you had the impeller in your hand. But once the pump is together the cover plate would not let the shaft move forward. The only function of that circlip when the pump is operational is to keep the shaft from moving back toward the engine, which it could do, but not very far and it would abutt on the engine fitting turning the impeller shaft. From the wear marks on the engine end of the impeller of the old pump with 400 hours on it without a circlip, it seems as if it did not move at all. There was no damage at the engine end of the shaft suggestive of an incorrect position of it.
Just thought I should ask Oberdorfer the same question. I will post their reply.
Geoff Johnson
Fellow Ericson Owner
Did you ever get an answer from Oberdorfer?