Autoprop Rebuild

[scfoster]

Originally Posted by kenbo

You could try valve grinding paste and a 3M pad but that brinnelling is so mild you could ignore it.

The more I think about it, I tend to agree. This is not a surface that sees a lot of high load rotations. I think what I'll do, now that I have the tools, is to pull the prop every two years and inspect for additional wear, now that there's a visual baseline. Especially since it's on the blade, not the hub. Can always replace a blade if needed.

[scfoster]

What's the best grease to use?

[kenbo]

I've always used this https://marinepartssource.com/14-oz-triple-guard-grease-johnson-evinrude-775776.html
But I'm sure other manufacturers have similar grease.

[scfoster]

Originally Posted by kenbo

I've always used this https://marinepartssource.com/14-oz-...de-775776.html
But I'm sure other manufacturers have similar grease.

Thanks. This Stay-Lube grease gets good reviews on Amazon.
In the Bruntons video (7:30 mark) he states to use boat trailer bearing grease.

https://www.youtube.com/watch?v=twdllnYKyDs

[kenbo]

Wheel bearing grease is formulated to not run out at elevated temperature. The grease I referred to is not and it's totally waterproof. Over the years it's become my go to for underwater grease YMMV.

[scfoster]

Not sure why but Bruntons went dark on the bearing race quote. All the more reason to get on with rebuild and check on it in 2 years.

Decided to go with PropGlide instead of using the antifouling bottom coat used on the rest of the boat. Stuff is not cheap. Also going to use it on the bow thruster propeller, so have to do all this in one shot, given the 2-part mixing nature of the primer coat. The instructions call for sanding with 80 grit then 2 coats of primer.

In order to keep the coating out of unwanted areas, I'll apply the propglide to the disassembled blades and hub, rather than fully assembled. This was an issue with the antifouling applied a bit too liberally, contributing to the blades not rotating smoothly.

Weighed the blades and they came in at (1) 54.21oz (2) 54.95oz (3) 54.46oz. Since it's all relative, didn't bother with grams. Did not weigh the caps as they still need cleaning (do that today). Will mix and match the caps to get the weights (blade + cap) as close as possible. Looks like there is enough material in the caps to take off some weight if needed. Don't really want to start drilling the blades. Weighed all of the individual rebuild parts and was surprised that everything weighed the same measured to 100th of an ounce.

[Dockhead]

Originally Posted by scfoster

Got everything apart, was not easy but only one busted knuckle so that's a win.

Had ordered the $292 rebuild kit from King Propulsion located in the USA. Can't recommend them enough. Rod responded sometimes in minutes.

Now the bad news. As suspected the single owner of the boat (prior to me) probably never had the prop serviced. It appears that one of the bearing races is marked up and will more than likely have to go back for burnishing by the factory. Will probably send the entire assembly while I'm at it. Sucks but I did save $200 on tools (boat logic ). Should get a service quote shortly.

New races come with the new bearings! Relax! No need to burnish anything or send anything. Pull those races out and throw them away and have a beer.

Brinnelling of the bearing races is a perennial issue with these props. I believe too tight or too loosely torqued retaining nuts may exacerbate the problem, as probably does motoring for a long time at a constant RPM. I replace those bearings in mine every 3 or 4 years.

[Dockhead]

As far as tools are concerned:

I bought the whole set of Brunton tools and never regretted it. The puller could probably be replaced by a harmonic balancer puller with trial and error, but the locknut spanner, and the peg spanners are irreplaceable: Autoprop Spares - Shop You will also for sure want the grease nozzle, if your boat didn't have one when you bought her.

Using the factory tools, I find tearing down and rebuilding the Autoprop to be a snap. Full rebuild takes me less than an hour. I pull a blade off mine every year just to have a look -- it only takes a few minutes.

You do NOT, by the way, have to pull the prop off, to rebuild it. I find it easier, in fact, with it on the shaft.

[Dockhead]

Originally Posted by scfoster

Not sure why but Bruntons went dark on the bearing race quote. All the more reason to get on with rebuild and check on it in 2 years.. . .

Bruntons went dark because they don't sell the races separately -- they come with the bearings. Do NOT reuse the old bearing races! See post above.

[scfoster]

Originally Posted by Dockhead

New races come with the new bearings! Relax! No need to burnish anything or send anything. Pull those races out and throw them away and have a beer.

I think you're either thinking of an H6 Autoprop or the replaceable roller bearings with accompanying races.

The races which capture the loose ball bearings are not replaceable. This is mentioned in the Bruntons' YouTube videos.

[scfoster]

Originally Posted by Dockhead

As far as tools are concerned:

I bought the whole set of Brunton tools and never regretted it. The puller could probably be replaced by a harmonic balancer puller with trial and error, but the locknut spanner, and the peg spanners are irreplaceable: Autoprop Spares - Shop You will also for sure want the grease nozzle, if your boat didn't have one when you bought her.

Made my own peg spanners, including a 4 point spanner for the caps, per the Bruntons' YouTube videos. Having a much longer lever arm (36" bar stock) helps. The one missing item is having a tool to torque the bearings during install. Will make one with a HarborFreight socket and a grinder, to make the needed tabs. Would have purchased the tools but the lead time to get them from the UK was too long for me. USA-side tools were backordered.

Using the factory tools, I find tearing down and rebuilding the Autoprop to be a snap. Full rebuild takes me less than an hour. I pull a blade off mine every year just to have a look -- it only takes a few minutes.

You do NOT, by the way, have to pull the prop off, to rebuild it. I find it easier, in fact, with it on the shaft.

Agree about doing it on the shaft. Removed due to cold weather, wanting to clean & refinish the prop assembly and the need to replace the cutlass bearing. Thankfully the ratty old cutlass bearing rotated freely (after removing the screws) and came out by hand rotating the shaft.

[Dockhead]

Originally Posted by scfoster

I think you're either thinking of an H6 Autoprop or the replaceable roller bearings with accompanying races.

The races which capture the loose ball bearings are not replaceable. This is mentioned in the Bruntons' YouTube videos.

New races come with the bearing kits for the H5 with loose balls too:





H5 Ball Bearing Kit


Or maybe you have the old seawater lubricated type?

[Frankly]

On both my H5 BB with sea water lubrication the large bearing races are machined into the hub and bottom of the blades. The interior bearing is also a ball bearing with replacable races. About 10 or so years back I sent my AP back to the factory to have the large bearing surfaces remachined. Bruntons said that the brinelling was too deep for cleaning up and still maintain the required outside clearances. I told them to remove the max and send it back (we are now into $250 postage plus repairs). They got the worst, I installed new bearings and it was still working fine when I stumbled over the ebay replacement last Spring. It now is carried as a spare along with the fixed 3 blade.


I have a couple of pictures but will have to get to my desktop, can't figure how to add on this da## tablet.
The pictures will make you feel a lot better about your race condition.


Frankly

[Dockhead]

Originally Posted by Frankly

On both my H5 BB with sea water lubrication the large bearing races are machined into the hub and bottom of the blades. The interior bearing is also a ball bearing with replacable races. About 10 or so years I sent my AP back to the factory to have the large bearing surfaces remachined. Bruntons said that the in the brinelling was too deep for cleaning up and still maintain the required outside clearances. I told them to remove the max and send it back (we are now into $250 postage plus repairs). They got the worst, I installed new bearings and it was still working fine when I stumbled over the ebay replacement last Spring. It now is carried as a spare along with the fixed 3 blade.

Frankly

Ah, OK, then that explains it.


I actually had one of those sea water lubricated H5's, on my previous boat, but unlike my present H6, which requires frequent service, I never even took the H5 apart, so I'm not familiar with its insides.


I sure don't like the idea of having the races machined into the hub -- ick! The bearing races are THE number one wear part on my H6. The reason why I rebuild the prop every 1200 hours or so. The races inevitably get brinelled. Everything else, including the seals, are still fine at that age.

[MikeHoncho]

I have two of the older ball bearing (what you show) props one is worn like yours and sitting on my bench ready for install and the other is a lot worse and going to need machining. King said it was going be be about $600 plus shipping and a rebuild kit if I remember right.
What you show in the first picture is a ball bearing version but the rebuilt kit you show is the newer greases bearing version. The ball bearing version takes no grease per the manufacture.