Yanmar 2YM15 trying to replace alternator belt
Posted by btongeo@reddit | sailing | View on Reddit | 10 comments
Hi folks
I'm trying to work out if I'm missing something super obvious. last time I used my boat I noticed the belt was slipping. I bought a couple of new ones and at the very least I was going to try re-tensioning or maybe just swapping it out as the boat is new to me and I don't know when it was last done.
I've loosened the three bolts that I can see holding the alternator but for the life of me I can't get it to move.
Am I missing something obvious?
When I work out how to post a video I'll do so.
Raneynickelfire@reddit
It's on a sliding bracket. Loosen both bolts, and tap the one on the bracket until it moves.
That's it.
Unusual_Holiday_Flo@reddit
Knocking it with a rubber mallet, two even five pounder, won’t hurt the alternator or bracket. Of course don’t be careless or destructive, but you’re working with cast metal engineered to run lifetimes under vibrations, heat, and pressure… it can handle a few hammer blows.
whyrumalwaysgone@reddit
General idea is there is a pivot bolt and a locking bolt. Loosen both, try to get movement any direction. Likely some PB blaster on both will help, you have some corrosion holding it tight. A wood scrap like the handle of a hammer is useful for nondestructive prying, do not beat on it with a hammer
LameBMX@reddit
just remove the alternator. aint gotta disconnect it. confirm the top is the pivot and the bottom has a slot. I hope the others are right, and there is a slot down there. that would mean there is a nut on the back of that bolt. just like on the top. since you talked about the top, you may just be spinning the bolt/nut on the bottom and not really loosening it, hence why its hard to tension.
I dont see a slot though. if there is no slot. you may need to find belts part number. confirm you got the right belt. belt part numbers generally contain their dimensions. with some online lookup you can determine the part number for a slightly smaller belt.
lastly. if its functioning correctly, but noisy. clean everything while the belts off. if still noisy hit the contact surfaces with a bar of basic no frills soap while running. use something to hold the soap firmly and try not to lose a finger.
btongeo@reddit (OP)
There is a slot yes. Maybe there's a nut on the back, that is possible. I'll have another look and revert
weezthejooce@reddit
I used to have one of these. Was one of the bolts on a sliding bracket thing? If you loosen that and the top bolt, the alternator should swing up and down to adjust tension. I might be misremembering though.
btongeo@reddit (OP)
Yeah the right-hand most bottom bolt is on the slidey thing and I undid that and the other three, but no movement whatsoever. I think it needs some carefully applied brute force at this stage as I can't see what else could possibly be holding it
btongeo@reddit (OP)
Yeah I did try loosening everything I could see but it didn't budge, I reckon some more gentle persuasion with a mallet might be called for.
And yes I'm planning to just replace it once I get it off - one less thing to worry about 😂
NoobOfTheSquareTable@reddit
Might be a bolt on the back of the lower bracket and the bolt on the front locks it
Also if you loosen the other bolt at the base to the left of the first one you loosened it allows the slot/slide part that the first bolt is in to move more and make it easier to adjust everything
Monkey_Fiddler@reddit
hard to tell from the photo and I don't have the same engine but it looks like the bottom bolt goes into a slot? give that bracket a tap and it should move along the slot. it will be stiff of course