Oberdorfer pump snap ring and lock washers

[HerbertFriedman]

I just replaced the impeller on my oberdorfer pump. I could not push the impeller in enough to insert the snap ring, pump runs fine, is that a problem. Also there were no lock washers on the four screws securing the cover plate. With all that vibration, should lock washers be used?

 

[Christian Williams]

Oberdorfer doesn't use lock washers on the cover plate. I'd probably try again to get the snap ring on, but I doubt it matters.

 

[Alan Gomes]

The snap ring is unnecessary. Leave it off—unless you completely remove the entire pump for storage or shipping and want to be sure the shaft does not slide out of the back of the pump.

 

[HerbertFriedman]

thanks for the info on the snap ring. Regarding the lock washers, has anyone ever seen those bolts work loose from all the engine vibration, and is there any downside to installing lock washers?

 

[Frank Langer]

thanks for the info on the snap ring. Regarding the lock washers, has anyone ever seen those bolts work loose from all the engine vibration, and is there any downside to installing lock washers?

Sixteen years ownership with this boat and oberdorfer pump, and my 5416 16 hp universal diesel, and the screws have never come loose. I don't overtighten too much as I don't want to strip the screws, but I ensure they are snug.
Frank