83-87 H31 Cutlass Bearing Replacement - Again

[wufibugs]

Read all the posts from a search on this unattractive task. From what I gather, there are two possibilities. (1) Remove the cutlass bearing and apparently that allows enough play to slide the shaft by the rudder/skeg. Or does it? (2) After the prop is removed, elevate the drivetrain and pull the shaft out the front. Unfortunately, I'm not visualizing how the latter works.
1. First, what are the dimensions of the cutlass bearing?
2. Is it just the rear of the engine/trans that is elevated, or does the entire engine/trans need to be hoisted?
3. Once the engine is elevated, I assume the shaft slides forward under the drivetrain and is pulled out from beneath the hatch?
4. There was a suggestion about inflating a ball under the engine to raise it after loosening the rear motor mounts. Wouldn't the ball impede pulling the shaft forward?
5. Finally, the homemade cutlass bearing removal tool. From deep in the archives, someone had the specs and instruction on making it. Could that be provided yet again.

 

[wufibugs]

Just for general information, Eddie at Hunter-Marlowe says the cutlass bearing on these boats is 1" ID X 1.25" OD X 4" long. He says it can then be trimmed to length, but I suspect the shaft logs should all be standard 4".

 

[snows]

Cutlass Bearing Removal Tool

You can see the tool I made specifically for a 1.25" prop shaft at http://www.svctime.blogspot.com/p/port.html. You would need to change some of the dimensions of the materials for your 1" shaft.

Good luck,

Daniel
s/v C-Time
http://svctime.blogspot.com

 

[wufibugs]

Thanks so much, Daniel. You thought this through carefully. Not being a sophisticated machinist, I have a few questions.
1. I assume the 1.5" low carbon tubing is the "dummy" you used to push out the old bearing. Looks like you cut a slit in it. Why since it is already thinner material than the bearing? I assume you and others do not recommend using the new bearing to do that.
2. You used very high grade materials. I doubt I will keep this boat longer than I anticipate this replacement bearing will last, and my next purchase will not likely be able to make use of the same tool. Do you think I could get away with somewhat less expensive materials and still get the job done? For example you use 3/4' bar. Do you feel that thickness is necessary to get the old bearing moving and make sure the edges don't champfer?
3. You used 18" of rod on each side. My bearing is 4" long. Seems I should be able to get away with no more than 12" on each side?
4. How did you prepare the inside of the shaft log? Light sanding? What did you use as a lubricant?

 

[mr c]

This is a post that I found with different materials. I just copied it in. Hope it helps. I will find the pic and repost.
The cutless bearing was replaced due to excessive play and vibration. A bearing press was manufactured to get the job done. There is no need to remove the drive shaft. Remove the set screws from the strut. There should be 2 setscrews inside each hole. Soak the contact point between the bearing and strut with penetrating oil such as PBlast. May take days.

Need two flanges and a threaded 1” x 6” black iron pipe from Home Depot. The inside diameter of the black iron pipe is slightly bigger than 1”. Cut one end off and make square. Screw the one end onto a flange. Use a new cutless bearing as guide, have a machine shop turn down the black iron pipe to slightly smaller than the bearing.

The second flange, use a file or grinder stone to grind away the threads. Make sure it is bigger than the outside diameter of the cutless bearing. Cut a slot about 1” to slide over the drive shaft. Enlarge the holes on the flange to 3/8”.

Get 3 x 3/8” x 12” threaded rods and 9 nuts. Use the threaded rod to press out the old bearing. Grease the rod will help. Start with 3 rods. Once the old bearing moved, you can go down to just 2 rods. Heat the outside of the strut with a blow torch may help the penetrating oil to loosen the bond.

Once the bearing is pushed out of the strut, use an angle grinder with a cutter blade to cut a slit (carefully). Install the new bearing using the same press. Use a hose clamp to ensure the bearing and the press is aligned. The old bearing is uses as a shield for the drive shaft. Put some anti-seize compound on the bearing to ease effort for the next time. Remove the old bearing afterwards.

 

[mr c]

 

[snows]

Cutlass Bearing Replacement

Thanks so much, Daniel. You thought this through carefully. Not being a sophisticated machinist, I have a few questions.
1. I assume the 1.5" low carbon tubing is the "dummy" you used to push out the old bearing. Looks like you cut a slit in it. Why since it is already thinner material than the bearing? I assume you and others do not recommend using the new bearing to do that.
2. You used very high grade materials. I doubt I will keep this boat longer than I anticipate this replacement bearing will last, and my next purchase will not likely be able to make use of the same tool. Do you think I could get away with somewhat less expensive materials and still get the job done? For example you use 3/4' bar. Do you feel that thickness is necessary to get the old bearing moving and make sure the edges don't champfer?
3. You used 18" of rod on each side. My bearing is 4" long. Seems I should be able to get away with no more than 12" on each side?
4. How did you prepare the inside of the shaft log? Light sanding? What did you use as a lubricant?

1. As another poster mentioned, if you drive the old bearing UP the prop shaft and split it with a grinder, then the "dummy" CAN be a single piece. I elected to drive the old bearing DOWN the prop shaft, thus requiring that the "dummy" be split. Also, the old bearing was very tight and became deformed as it was pushed out. If you used the new bearing to push out the old, then you might deform the new bearing.
2. As mentioned above, the old bearing was VERY tight, so I would be afraid thinner barstock might bend.
3. 12" should work. I just didn't want to be caught short, so I cut a 36" rod in half.
4. I just blew out loose dust, no sanding. As tight as the old bearing was, I figured it cleaned out the strut pretty well as it was coming out. I didn't want to increase the chances of the new bearing turning in the strut, so no lubricant either.

 

[Don Crowther]

I've just finished this job last month. My bearing refused to move. I ended up removing the strut and taking it into a machine shop.
I've attached another bearing removal tool for you to compare.
I used such a tool on my 31. The bearing slid out without any problems.
If your going though bearings that quickly maybe your shaft is bent or your engine is out of alignment.

 

[Don Crowther]

sorry hit the enter button before attaching this pdf.

 

[wufibugs]

MrC, curious as to how one gets the forward flange onto the shaft between the strut and the hull? Wouldn't it have to be cut in half and then cross mounted to another one much as Don's tool is constructed?

 

[mr c]

If you look close to the first pic you can see a notch for the shaft.