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Old 11-26-2012
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Re: Going thru alternator belts???

Quote:
Originally Posted by Maine Sail View Post
The Universal engines are not the only ones that have improperly sized pivot bolts. Many factory engines including Yanmar, Volvo/Perkins and Universal often ship with the wrong sized bolt for the alternator to pivot on. With a 35A alt this is rarely a problem but when you go to 80A+ it quickly becomes belt dust bonanza..

Universal also shipped a number of engines where the Motorola alts had SAE holes and yet others with metric, go figure. The alt bracket upgrade, IMHO, is a rube Goldberg fix and rather poorly engineered, but still far better than the original.

Please be aware that the long alternator 3/8" bolt that comes with the kit is most often the WRONG size. It is much to sloppy a fit in the bracket. The hole in the bracket works MUCH better with a metric bolt. I replace it with a metric bolt and occasionally need to then drill the alt to the proper fit. The problem is the Motorola alts shipped in both metric and US sizes over the years. The upgrade bracket is drilled for metric but Westerbeke ships a 3/8" bolt.. Belt issues with the new bracket are often due to the sloppy incorrect bolt Westerbeke supplies. It allows the alternator to "twist off" and create uneven belt wear and creates wear on the alternator foot mount.

Also the new bracket has oval holes for a reason, but every one I have seen installed has never taken advantage of them. You may not need to but you really should align the bracket fore/aft on the motor so the belt is in proper alignment.. This may mean spacer washers under the thermostat end of the mount. The one I just did required two metric washers to shim it forward..

Sloppy Fitting Westerbeke Bolt


A much better fit:


New bolt on left, Westerbeke supplied "sloppy" bolt on right:


Forward Align


If you forward align place shim washers in the space:


Aft Align:



On the adjusting arm bolts I also go one step further.

I get a real long bolt, split washer and nyloc nut. I then adjust the arm and tighten the bolts hard. Once tight I install the "locking" nuts. I've yet to have one vibrate loose after this fix..

Alternator Ear End (gets both split washer and nylock nut. If the alt over heats it could melt the nyloc feature.)

Slotted end of adjusting arm: (this should never get hot enough to melt the nyloc if it does you have bigger issues.)
Curious as to the use of coarse thread and not fine? Looks like grade 8 bolts on the replacement, nice.
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