Oberdorfer ID

[Theo Lewis]

Good morning,
Currently changing impellers on my fresh and raw water pumps. I have put about 75 hours on this engine since purchasing the boat 3 yrs ago. Fresh (Jabsco) was straightforward. I did purchase the impeller puller for the Oberdorfer. Access is brutal (Ranger 29). While assessing the situation and reading about these pumps I learned about and expected to find a grease cup or a zerk on the side and a brass plug underneath. What I found is hex headed brass plug underneath as expected and square headed brass plug in the grease cup port. Are there Oberdorfer models that do not require periodic greasing?

[Al Schober]

That square head plug is where the grease cup belongs. If you're on speaking terms with the PO, you could ask him what happened to it. I don't think our host offers the grease cup as a spare part. A quick search on Amazon turned up a lot of grease cups for barbeque grills but nothing for an A4.
Consider the factors: an old pump (they do wear out), unlubricated for ?? years, poor access. Might be time to bite the bullet and install our host's ball bearing, face seal pump. I put one on my engine when I changed to glycol cooling. A little sea water leak was no big deal - went to the bilge. A glycol leak is like losing blood - pretty soon you run out!

[Theo Lewis]

Thank you Al.

Always great advice. I figured the POs had lost it, just surprised….ok not surprised, that they plugged it off. I swear I found it and probably have it in a bag of mystery junk. Anyone know offhand what the thread is? There are many replacement options, new for 70 from several sources and NOS on EBay for about 50. Plenty of non-stock options around 10, brass, they look good, just need the thread. Yes, the backside of the engine remains a shameful mess as it is grim to get to. Planning on getting in there to clean when hauled out later in the month.

[Dave Neptune]

1/8 NPT standard pipe thread.

Dave Neptune

[Easy Rider]

I hear your pain. Access to that pump while attempting to change the impellor without removing the whole pump is a pig of a job on a Ranger 29. You almost have to be standing on your head. Then try backing out - that's another experience altogether. I finally got smart and bought a bolt extender for the inner bolt and remove the whole pump for impellor changes. It's also good opportunity to clean it up and examine it for wear.