Impeller hub lubrication

[geoffschultz]

I have a Yanmar 3JH engine where the water pump is about 2-3" away from the starter and in my case is only visible from the top once you remove the alternator. Every time I change the impeller it's about an hour job to slowly walk it out of the pump using a long pair of right angle needle nose pliers. To put it mildly, I don't enjoy this job.

I've tried various methods of lubricating the hub shaft, but clearly none has made the removal job any easier. Does anyone have any great ideas on how to improve this situation?

-- Geoff

 

[Steve Dion]

Geoff:

On our Hunter Vision 36 we have the same engine. Our configuration allowed me to put a door on the side of the engine box, that allows for easier access. I also added a SpeedSeal to make the r/r of the cover easier.

As far a greasing the shaft, I would think that something like SuperLube teflon grease may help. I also purchase a pair of bend nose needle nose pliers which should also help.

 

[geoffschultz]

It only took about 1.5 hours to get the impeller off. Sure hope that I never have to do it in an emergency! That's one of the reasons that I replace them at the recommended interval.

And yes, I do have a Speed Seal, but that wasn't the issue. Lack of clear access is. I have a water tank next to it, so there's no way to gain access from the side. Anyhow, I tried the SuperLube. We'll see how that works when I replace it next.

- Geoff

 

[Warren Milberg]

I lube my impeller shaft with a bio-degradable liquid soap. I then use two needle nosed pliers to work the impeller out. It is never easy. In your case, do you have the space to use a Jabsco Impeller Puller? While expensive (+/-$90), this tool would ease the task.

 

[geoffschultz]

In your case, do you have the space to use a Jabsco Impeller Puller? While expensive (+/-$90), this tool would ease the task.

I would love to be able to use one, but there's only 3" between the starter and the pump and I've never seen one small enough to fit in there.

-- Geoff

 

[Steve Dion]

Warren: that device would be wonderful if there was more than 2-3" between the cover and the starter.

The cover faces towards the aft.

Geoff: There are some new impellers that have some special threads that allow one to "screw" in the device to the impeller. It will NOT work with anything other than the new YANMAR OEM impellers. I will try to find the device for you.

 

[Steve Dion]

Here is a little blurb on the device.

"I recently replaced the impeller on my 4JH4TE and experienced the same frustration w/ the access (or lack thereof), and the difficulty in removing the old impeller. I was sold a replacement made by Johnson, a 1027B. It looked identical to the OEM Yanmar impeller (also made by Johnson), except for one small detail...the Yanmar has a few threads on one end. This is to allow a Yanmar impeller puller, basically a jack screw within a threaded insert, to be used. I now have one of these Yanmar pullers, and have bought a couple of the Yanmar impellers, at nearly 2x the cost of the Johnson unit. But it's amazing how easy it is to remove using the puller tool. Well worth it, at least to me. I asked my mechanic about the availability of the Johnson impellers w/ the threads, direct from Johnson w/o the Yanmar markup. He tried to find, but was told that it is a proprietary Yanmar part, even though it is stamped "Johnson", and no doubt made by them for Yan. All I know is that it sure makes removal a piece of cake compared to the unthreaded 1027B."

 

[Steve Dion]

The impeller is 129670-42531.

The puller assembly is 129671-92110.

 

[geoffschultz]

the Yanmar has a few threads on one end. This is to allow a Yanmar impeller puller, basically a jack screw within a threaded insert, to be used. I now have one of these Yanmar pullers, and have bought a couple of the Yanmar impellers, at nearly 2x the cost of the Johnson unit. But it's amazing how easy it is to remove using the puller tool."

I actually buy Yanmar impellers and unfortunately there are no threads on the hub.

-- Geoff

 

[Steve Dion]

Geoff: Check out this new part number 129670-42531, it has replaced the 129670-42530 (no threads).

I am going to order one next week just for a look-see.

 

[Joe2954]

Hand Cleaner Goop works well as a temporary lube for rubber products.

 

[Steve Dion]

Joe: The real issue is the extraction of the impeller. There is so little space in there (very poor design) to remove the impeller.

I think we need to be sure that the shaft and splines on the impeller is well lubricated with a grease that will not get diluted prior to the next change out. This "should" help in the next change out (not really sure about this). Then we need to determine if there is enough room to re-install the new impeller without r/r the starter.

While these photos are NOT from a Hunter the engine is the same.

http://ipphotos.com/view_ad.asp?Ad_ID=398

 

[SamLust]

Never-Seize on the shaft upon assembly. A little schpritz of silicone spray on the rubber and turn the engine to turn the impeller and distribute the silicone. Should ease removal. One of the very few places silicone spray is of any use at all. I also coat the rubber of the impeller with plumber's grease on assembly. Eases installation and protects during first start-up.