Oberdorfer Pump Snap Ring - Official Answer

[Alan Gomes]

Which is why I have a spare impeller sitting right next to a spare shaft, ready to go.

Thanks for bringing FACTS into the discussion.

Personally, I wouldn't recommend swapping out the shaft and the impeller as a unit, at leat not as a matter of course. (Maybe that's not what you're suggesting, depending on how one interprets your statement.) While you can do that, you do run the risk of nicking the seals with the shaft. If you are extremely careful you can avoid this, but I think the shaft replacement is better done on the work bench. In any case, I don't think it's necessary to swap out the shaft for simple impeller changes. My preference is to hold the shaft in and remove/replace only the impeller, so as not to run the risk of disturbing the seals.

 

[weekendrken]

IPSO, why originally I said Darin doesn’t have a clue what he’s talking about (from his verbatim reply - no matter the wording of question itself or in what manner it was asked!!)
The ring doesn’t “align” anything.
“Ingersoll Rand corporate answer.

Remember, Oberdorfer gave me the same run around (until I found someone there who could think outside the corporate box.)

I’ll give Darrin the benefit of the doubt that it’s not his fault - there’s probably no one originally there from Ob who knows anything much about the application. Only “the pump” itself, and then only the corporate spiel.
Does Mr Darin have a last name?

This is not atypical. One example, when I talked to Westerbeke they couldn’t understand what the problem was putting a 3” Hx on the m-25. “What do you mean you can’t get the dipstick out of the transmission? The Hx doesn’t have anything to do with the transmission, a 3” Hx is standard on the XP and there’s no problem like that.”
[Duh, the XP has a DIFFERENT bell housing that’s shaped for a3” Hx.]

Another example, Depco (some folks’ absolute gurus about pumps) had no clue why a customer w/ an m-25 would have a pump with a female shaft. “The owner must have changed the shaft.” The former marine pump manager used to email ME with those type head scratchers. They don’t know the complete application and permutations that Universal installed (like 202M-07 pumps when they couldn’t get enough Ob 202M-15 or Sherwood G5 pumps (which was a carbon copy of the Oberdorfer pump, same flange base.)

 

[Stu Jackson]

@jonelli

Thx much for your great detailed explanation.

Don't worry, there isn't a boating vendor yet that Ken hasn't found where he could do a better job. And he's usually right!

 

[weekendrken]

Alan

i absolutely ag

Personally, I wouldn't recommend swapping out the shaft and the impeller as a unit, at leat not as a matter of course. (Maybe that's not what you're suggesting, depending on how one interprets your statement.) While you can do that, you do run the risk of nicking the seals with the shaft. If you are extremely careful you can avoid this, but I think the shaft replacement is better done on the work bench. In any case, I don't think it's necessary to swap out the shaft for simple impeller changes. My preference is to hold the shaft in and remove/replace only the impeller, so as not to run the risk of disturbing the seals.

Alan I absolutely agree it’s not the preferred way. I’m just saying it’s ONE way of a quick change (with Ob’s stance that the cir-clip needs to be remain, or if an owner doesn’t believe that it doesn’t.)
With a slathering of SuperLube it can be gingerly inserted (especially with the male (vs female fork-end) shaft. And if its end is smoothed off.) The savior is that the most difficult seal (the lip facing the shaft end) is the first, right after the bearing. The second seal is marginally easier not to mess up (lip facing away from the shaft.)
On the bench is defo the cautious way to be messing with the shaft/seals unless one really knows what they’re doing and is very careful!!
BTW, I’ve had a few customers who had an impeller seized on the shaft and of course then had to pull both. I always recommend some SuperLube (or similar) on the shaft before slipping on the impeller. I don’t know how long lasting it would be, but.... can’t hurt.

I also agree with Stu that the mfgr should look at it ftom its vantage point. But should also provide good and accurate info to customers — such as, “Yes once installed...bla bla bla but we recommend you keep rhe clip on because ... bla bla bla.” That’s why the “101 Series” on the website is do valuable - it reveals to owners a lot that manufacturers/suppliers don’t (or won’t) tell us.