roaringgirl
Well-Known Member
I've had problems in the last year with them working loose due to the engine vibrations. So I do both the adjuster bolts and the pivot bolts up as tight as I can without risking destroying the studs or nuts.
Alternator drive belt tensioning.
- Thread starter tjbrace
- Start date
jwfrary
Well-Known Member
Standard belts are absolute garbage.
Go to your local parts store and ask for a 950 belt 13mm 10mm are ok in a jam. Gates or dayco are both good options.
And put a large thick washer behind the bolt head, increases surface area and therefore friction
Go to your local parts store and ask for a 950 belt 13mm 10mm are ok in a jam. Gates or dayco are both good options.
And put a large thick washer behind the bolt head, increases surface area and therefore friction
Spirit (of Glenans)
Well-Known Member
+1. Buying belts and filters of the same "marine" brand as the engine is just throwing away money. (Some of my ancestors were brought to Ireland from Scotland by Cromwell!)
It's relatively easy to look up the equivalcies on line and buy automotive ones.
Moodysailor
Well-Known Member
After an small initial period, there should be little to no stretch in the belt. They have a woven section to minimise this.
The most likely explanation is either premature wear on the belt, from corrosion/pitting on the pulleys (likely), or misalignment (unlikely). Or the alternator is slipping on the adjuster.
You could modify the adjuster so that is has a 'jacking bolt' arrangement (as fitted to many VP engines). These are particularly good, and service to prevent slippage.
Please do not be tempted to try and make your life easier by leaving the pivot bolt loose, as the vibration from the engine & alternator will cause damage - best case the bolt will snap, worst case, the mount or alternator case will fret and wear. I've seen all of those.
A surprisingly small amount of pitting on the pulleys can chew up V belts, when I worked as an engineer it took me a long time to convince one particular owner of this.
The most likely explanation is either premature wear on the belt, from corrosion/pitting on the pulleys (likely), or misalignment (unlikely). Or the alternator is slipping on the adjuster.
You could modify the adjuster so that is has a 'jacking bolt' arrangement (as fitted to many VP engines). These are particularly good, and service to prevent slippage.
Please do not be tempted to try and make your life easier by leaving the pivot bolt loose, as the vibration from the engine & alternator will cause damage - best case the bolt will snap, worst case, the mount or alternator case will fret and wear. I've seen all of those.
A surprisingly small amount of pitting on the pulleys can chew up V belts, when I worked as an engineer it took me a long time to convince one particular owner of this.
Topcat47
Well-Known Member
The Yanmar OEM belt for my 1GM10 is a Vee Belt. I replaced it last time with a proprietary toothed belt which has lasted better and does not nee such a high tension. The bolts that need to be "tight" are the ones on the adjustment strap the long bolt which acts as a hinge need not be so tight. I employ shake proof washers on all the bolts and nuts. The bolt on the adjuster should have a lock nut where it extends out of the alternator.