How difficult to replace crank bearing...???

[treedawg]

I've located a nice looking Yanmar 2500 for sale for $800.00.

I haven't spoke with the seller but he says the crank bearing needs replacing.

Is this a DIY type job for someone with basic mechanical skills..??

This would be a great parts tractor for some one with a 2500 but I'm not sure if it's something I'm capable of repairing.

td

 

[4570Man]

What's basic mechanic skills? A quick YouTube search will give you a better idea of what you're up against. I'd say you ability to figure stuff out is more important than your mechanic skills.

 

[California]

Rod bearings, or mains? I think the mains in these are near bulletproof so hopefully its just rod bearings.

I could be wrong but I think to do the mains on these you need to split the tractor and pull the crank/bearings module out the back of the block.

That would be over my head. I would carry the engine in to a real overhaul shop if it needed that. But you may have better skills and shop facilities than I do.

There are (? - used to be) portable crankshaft grinding services that can come out and clean up rod bearing journals. You might ask around and see if one exists close enough to serve you.

Another thought, I think Deere 850 has the same engine so finding one in good condition might be an alternative. If you can buy this tractor for $800 or less you still have some margin before you've overspent.

 

[Republic of Texas]

Buy it. If it's a dud, you can part it out. I have a John Deere 850 & a Yanmar 3110D so I would definitely buy some parts from you.

 

[LD1]

While I certainly think it would be worth the $800, I am not a fan of simply replacing rod bearings.

The engine as a whole needs checked out.

What caused the bearing to fail? Bad oil pump? Blocked passage? What else is on the verge of failing as well? Did the bearing spin? Etc Etc

 

[Shaneard]

Don't take a persons word that it "needs bearings", you may as well factor in the price to replace the whole engine if your really interested in buying it that way if you buy it and it doesn't need a complete engine rebuild then your better off. Bearings don't just go bad, something makes them go bad and usually it's a lack of oil and if that's the case it has more problems then a bearing.

What would a complete rebuild cost? How hard is it to find parts for one of these?

 

[normde2001]

What is the crank bearing, and how does he know it is bad?

 

[Republic of Texas]

What is the crank bearing?

Probably the main bearing I am assuming.

 

[RickB]

So if it needs a bearing and that diagnosis is made without the benefit of a teardown, who is to say it doesn't need a crankshaft?

 

[California]

This is one of those high-risk gambles that sometimes pan out, sometimes don't.

Overall I've encountered well over 50% winners but there's also been some $500 cars for example that were valueless. Worst was when I was a teen I paid $100 for the title to an old Mercedes that an acquaintance had parked at the ranch when he heard a rod knock. Opened it up and found the hardened steel timing chain, same material as a bicycle chain, had disintegrated and fine fragments had gouged every place lubed by oil. Don't recall but I think I had to give away that one free.

And an example of a winner - the Yanmar YM240 I've had 13 years now hasn't needed a thing since I spent an initial month back then remedying severe neglect and locating missing components - loose lugnuts, bashed headlights, unreliable ignition switch, plugged up hydraulic filter screen, dash warning lights dangling by my knee, Thermostart ($15 manifold heater) burned out, fuel filter assembly discarded and replaced by one for a lawnmower. I think a lot of people would have passed it up based on appearance. But it is fundamentally solid, it was just years behind on simple maintenance. Once I got it back conforming to spec that's all it ever needed to run like new. It still looks a little 'experienced'. This gamble was a winner, I think buying a brand new tractor at that time would have had more spent on repairs by now compared to this.

I hope treedawg gets lucky with this YM2500. If he passes it up then somebody will eventually buy it, maybe we'll see someone else appear here with the same questions. It's definitely a high risk gamble.