What is considered too much play in the cutlass bearing

[preservedkillick]

I need to make a decision on replacing my prop shaft. The concern is that the shaft is worn in the area of the cutlass bearing. The shaft constantly measures .8725 diameter down the length of the shaft until you hit the area where the shaft rides in the cutlass bearing - the lowest reading is .8650 ~ a difference of 7.5 thousandths.

With the inside diameter of the new cutlass bearing @ .8810 there would be a difference of 16 thousandths for play. Is this considered excessive? Lead to vibration? Are we talking "Princes and the Pea" here? Or am I likely to notice a real difference with a new prop shaft?

jeff

[DrB]

of inch total play so 0.0625 or 62.5 thousands. Most folks say that, with the shaft centered, if you can get more than a 30 mil shim between the CB and the shaft, you should replace.

DrB

[Gene T]

I am surprised the cutlass is larger than the shaft. I have never measured one but the last one I put in had an interference fit. I replaced one once where I could still move the shaft by a noticeable amount afterwards and that cutlass lasted many years. More play just means it will wear out faster. How much do you motor? It may not really be an issue.

[preservedkillick]

I just remeasured the cutlass bearing ID again. A new Johnson Duramax. I get anything from .8870 to .8800. Tough to measure rubber accurately. I'm starting to think I'm fussing over something that's insignificant. I'm still a ways from 1/16th.

[JimsCAL]

7-8 thousands wear is nothing to worry about. You'll be fine.

[Kutter]

Thats still within clearances for Maritex water lubricated shaft bearings.
in mm
For a 22.00mm shaft (0.8661)
New clearance is ID 22.12 - 22.22 (0.8709 - 0.8748)
Replace when it gets to ID 22.55 (0.8878)
There is a calculator on our website where you put in your shaft size and it gives bearing clearances.