Do hubs wear out?
 

I have some maximus props with solid hubs. The hubs seem loose in the props they, will just fall out and seem to be a little loose. Normal or a problem?

I also run solid hubs....I had one guy tell me one time that when hey got loose to replace them but not sure how credible he was. I would be interested to hear a more solid tech answer here.

Found this on a site:

Any cracking in the hub of a marine propeller must be regarded as serious, and any steps which can be taken to prevent such cracking are desirable. The purpose of this paper is to enumerate some of the more obvious causes of hub cracking and to suggest certain precautionary practices which can be adopted by all those who are vitally interested in the alleviation of the problem.
It is suggested that there are at least four principal causes of hub cracking. These are listed in what is perhaps the order of their importance.

1. Excessive heating at installation or removal.
2. Improper fit of key in keyways.
3. Improper fit of shaft and hub tapers.
4. Residual casting stresses.

Thanks kyboy1020 but that is irrelevent for this discusion. That info would be more suited for hub failures. Curious, who wrote that? Sounds like something I had in service training at Merc.

I assume the Maximus props have the HD inserts. I'll make a long story short. Trust me it is lond since I was involved in the fit process with the delrin strips during the development at Merc Racing in 2002.

Answer, prop hub bore on the large end of the ID tolerances. Insert on the small side of the OD tolerances. No harm if slightly loose and can fall out. It can't go anywhere after the 55 ft/lbs. of tq.

If it bothers you, wrap the insert 2-3 wraps of 1-2 masking tape and press it into the prop.

Seriously.

Brett

Thanks for the reply Brett. I'll need some new labbed Maximus for my power upgrade soon. Eric