This turned out to be a bit of a a struggle, when in fact it should be easy. When I bought this (Oberdorfer) pump from Depco, it came ready to mount with impeller installed so simple bolt on deal, replacing my old Sherwood which had failed after 30 years or so. Now that 5 years have passed (low boat usage each year, maybe 8-9 trips average) I decided to replace the impeller with one I got from Depco same time as the new pump, so a factory original type as far as I know.
So, the old one came out easily using a screwdriver to hold the shaft and needlenose pliers to pull the impeller out. Saw no broken or cracked vanes, but went ahead and installed the new one as intended. (Will keep the old one for an emergency.) Slid it onto the shaft, but “hey, what’s going on here…?” it would not go on all the way, maybe 1/8 to 3/16 left to go! Tapped it a bit, still no go. Finally, pulled the shaft out and tried to get it to go on by tapping. Still not on far enough to get the circlip on. Finally had to drive home so I could use my bench vise to tap the shaft downward and off the impeller. Greased the heck out of it, but it still stopped about 1/8” from the “stop point”. Took a block of wood as buffer and tapped with hammer and it finally went to the stop. All easy after that, but I am wondering what the heck that was all about.
I will say, in general, on these type pumps (not Sherwoods as then you must reinstall the whole pump) removing the entire shaft makes the job easier than working on it in place. But if you get an impeller like mine, you will have the same struggle I did. No amount of grease will help.
Hope you all get impellers that are friendlier than this one. There are a lot of worn machine tools in this country maybe this part came from one of them.
So, the old one came out easily using a screwdriver to hold the shaft and needlenose pliers to pull the impeller out. Saw no broken or cracked vanes, but went ahead and installed the new one as intended. (Will keep the old one for an emergency.) Slid it onto the shaft, but “hey, what’s going on here…?” it would not go on all the way, maybe 1/8 to 3/16 left to go! Tapped it a bit, still no go. Finally, pulled the shaft out and tried to get it to go on by tapping. Still not on far enough to get the circlip on. Finally had to drive home so I could use my bench vise to tap the shaft downward and off the impeller. Greased the heck out of it, but it still stopped about 1/8” from the “stop point”. Took a block of wood as buffer and tapped with hammer and it finally went to the stop. All easy after that, but I am wondering what the heck that was all about.
I will say, in general, on these type pumps (not Sherwoods as then you must reinstall the whole pump) removing the entire shaft makes the job easier than working on it in place. But if you get an impeller like mine, you will have the same struggle I did. No amount of grease will help.
Hope you all get impellers that are friendlier than this one. There are a lot of worn machine tools in this country maybe this part came from one of them.
