Gear hardness and grit in mercruisers

[JustJason]

Re: Gear hardness and grit in mercruisers

Don't ever pick up bearings(balls or rollers) with a magnet. That was a clear warning from the instructor that it would rearrange the molecules and leave the bearing 'less hard',

Man... with the amount of crap I drop and pick up with magnets I'm most definitely screwed!!!

 

[fishrdan]

Re: Gear hardness and grit in mercruisers

Soooo, was I right or wrong about pulling the bearing carrier out of the LU and gaining access to clean out all the magnet pieces?

 

[wca_tim]

Re: Gear hardness and grit in mercruisers

One of the things you will have removing the small fragments of magnets is how tenacious they will cling to the gears and bearings.

Also, any steel part touched by a magnet becomes magnetized. Maybe only slightly but think...it will attract every bit of steel grindings within the drive.


Just to tell the story as told to me. My instructor went to a merc training/information class given by Mercruiser to MERC Mechanics. One of the authorized merc mechanic 'students' dropped the lower shaft bearings and swept them up with a magnetic pick-up broom. The Merc instructor promptly told him to throw thew bearings away.

Personally, I don't care if you decide to test you theory and magnetize all your bearings and gears. In fact, be my guest.

It seems some people just don't feel the need to learn anything cuz they know it all.

if you look in one of my earlier posts, I gave a reference to a recent, peer reviewed journal article describing a study where carefully designed tests were done under controlled conditions to answer exactly the question some of us are going back and forth about (in a friendly fashion of course!)... with pulsed magnetic fields from something like 80 to 400 gauss. Part of the of the motivation for the questions and related work that's been done stems from wear rates in needle bearing applications where stray current and magnetism are present. think about things like alternator bearings, etc... and believe it or not, metal atoms (propper phrasology in this case is atoms) in steel and other ferrous metals move a good bit more than you would expect... even at temperatures couple hundred degrees below zero...

If magnetic currents are a problem with metal strength, I'm in real trouble... I spend a fair bit of time around superconducting magnets and have a long metal plate in one of my arms...

on the other stuff... you all are a mess...

 

[erikgreen]

Re: Gear hardness and grit in mercruisers

Okay, I thought I'd post the outcome.

The shop tried to call me but had the wrong number, so I hadn't heard back. I called them and found out it was done.

They went a bit beyond the work order I'd written, total bill is $412.52, but that includes them cleaning the magnet bits out, pressure testing, replacing an O-ring and seal in the upper half, re-testing, and filling with lube.

So a bit more than I'd wanted to pay, total now to repair this problem is about $750, but they did find and fix the upper seal problem. Now I just need to get the drive home, prime and paint, and then take it out on the lake.

After I figure out where the extra money is going to come from, of course.

I didn't ask them about magnets and bearings

Erik

 

[wca_tim]

Re: Gear hardness and grit in mercruisers

always remember that your time is worth something. While many of use "enjoy" fixing things ourselves or do so out of necessity, it is not free. Sounds like it was worth the expense to me...