Cutlass Bearing, How Much Play?

oldersalt · Nov 19, 2012

If you can feel it wiggle, it's probably time to change it. If you do it over the winter you'll save the cost of an emergency haulout and all that hassle, and you'll have one less item to worry about over the summer.

Ralph Johnstone · Nov 19, 2012

As Oldersalt Says .........................

oldersalt said:
If you can feel it wiggle, it's probably time to change it. If you do it over the winter you'll save the cost of an emergency haulout and all that hassle, and you'll have one less item to worry about over the summer.

................. any play indicates it's time to replace. 3/16" play would mean self-destruction is imminent.

My engine has around 1800 running hours and not a trace of play yet. Maybe a result of constantly checking the engine alignment and keeping the prop clean. Here, I must confess to coating the prop with some new goop every year and haven't found one yet that works in our waters.

No disrespect to Mr. Casey, but IMHO some of his ideas on engines are quite "different". I'd defer to Nigel as the final word.

capejt · Nov 19, 2012

A tad off topic, but Ralph-

What "goop" do you use on your prop, and how well does it work?

Ralph Johnstone · Nov 19, 2012

A Waste of Time .......................

capejt said:
What "goop" do you use on your prop, and how well does it work?

................... in my opinion. Let me count the ways:

diaper rash ointment - useless
diaper rash ointment with penicilin - useless
lanolin - useless
Molylube grease - useless
an unknown bottom paint - useless
Vaseline with Neomycin antibiotic - useless

Of course they're all useless because they're quickly eroded off the surface of the blades. I've never found a trace of the previous year's potion on the blades after a year of service (about 120 running hours).

I haven't done it in the last few years.

hewebb · Nov 22, 2012

Mine had a little less than 1/16 play in it and I decided to replace it. Getting the old out was quite a chore. I learned that in a previous life they installed a 3" where a 4" is required. I haven't checked the shaft alignment yet. I was wondering if I should install the new bearing first or just use shims I have to position the shaft. I have not removed the shaft.

JoeWhite · Nov 23, 2012

I had about 1/16 play and I replaced the bearing and the shaft. I found that the shaft was also worn out. I had 750 hours on the engine.

Rodd · Dec 7, 2012

i can wiggle so probably will replace. Question is, i only have about 300 hours since last changed 5 seasons ago. is this abnormal? should i be checking alignment? no vibration, so never felt alignment was an issue, but maybe it is??

thanks.

Rodd

Maine Sail · Dec 7, 2012

Rodd said:
i can wiggle so probably will replace. Question is, i only have about 300 hours since last changed 5 seasons ago. is this abnormal? should i be checking alignment? no vibration, so never felt alignment was an issue, but maybe it is??

thanks.

Rodd

It is not "normal" in the sense that it is right, but it is "normal" in the sense that most boats are HORRIBLY aligned thus premature cutlass wear. So you are in the "norm" more than out of it, sadly....

Our cutlass has nearly 700 hours on it and is as tight as the day it was new.... It is all about how well it is aligned as to how long it will go before it gets sloppy.

Rodd · Dec 8, 2012

Thanks Maine-
now that i know cutlass will be replaced, any tips for removing the shaft? I Have a bronze shaft that is easily separated from my V-drive; however, I remember having a real tough time getting the shaft to slide down through the old bearing. It was really a bear to get it all through the strut bearing. Any lubricant recommended or use of a slide hammer style weight on the shaft?

Also, I have read through your advice on packing. With the bronze shaft I seem to read that the preferred packing is just the traditional flax packing without graphite impregnated. Is this your latest thinking?

Rodd

Witzend · Dec 9, 2012

If your engine mounts are bad, this will cause vibration and/or torque deflection, mis-aligning the the drive train, causing premature cutlass bearing wear as well.

Rodd · Dec 28, 2012

hi Jim-
Happy holidays to you and the board!

I was checking your question and see that Nigel Calder recommends 1/16" play per inch of shaft diameter as being acceptable. You would fall into that category and. according to Calder, you don't need to replace the bearing yet. If you are at all concerned, though, and it's not too bad of a job, why not just replace it?

Rodd

Maine Sail · Dec 28, 2012

jimmcgee said:
Maine,
Back to my original question. Is 1/32 - 1/16 play on a 1" shaft too much play requiring replacement?

I've already decided to do the job but am wondering what's "normal".

Thanks,
Jim

I feel 1/16" is far to much slop but there are many boats out there running around with close to this, and they usually have vibration issues... Heck the rubber walls of many of these bearings is less than 1/16" thick so 1/16" thick means you have very little rubber left.... I'd probably be comfortable with 1/32" at the worst..

Normal is no "slop" side to side or up down and with a well aligned engine you can get thousands of hours with zero slop.. Ideally you should not feel any hard slop meaning when you wiggle the shaft all should be snug & tight. It should not be "free" then hit a wall then be "free" then hit the opposite wall. Walk around the yard and you'll see what I mean. You can feel "slop" vs. no slop...