Crankshaft problem on Y395??

Johnny P · Oct 3, 2009

Hello, Should read Y385!!!
Whilst using the tractor (Shire badged Jinma 28hp) a couple of days ago the engine developed a loud knocking noise. On investigation I found that if you got hold of the end of the crankshaft you can moved it backwards and forwards about 5-10mm. Any ideas what has happened and what I might need to put this right?

Thanks Johnny P

Bob Rooks · Oct 4, 2009

You should have some endo. I believe most fall into the .005" to .010" range.
Loud knocking could be anything from a bad injector, to a con rod, to something hitting the fan. Any smoke from the exhaust?

Johnny P · Oct 5, 2009

Hello Bob,

Only smoke from exhaust is when I start it up. Don't like to leave it running in case of doing any possible damage. I tried loosening the injector connections on each cylinder in turn to see if that would cure the knocking but unfortunately it didn't. Funny, but earlier in the day the knocking started I had tightened up an injector hold down, I think you call it, as there had been slight blowing coming from the area where the injector goes into the block. Could be a coincidence.

Johnny P

Rich Waugh · Oct 5, 2009

If you have 5-10 mm of end play in your crankshaft, something is definitely wrong there. As Bob noted, endplay should be no more than around .005" to .010" (0.13mm to 0.25mm) max. More than that and the crankshaft is floating around and whacking **** out of the sides of the journals, oil seals, etc.

I don't really know squat about these diesels, but on a gas engine I'd look at the front thrust washer. Could be something else on a diesel - I don't know if they even use thrust washers, but I'd think that they would.

I wouldn't run that engine until I knew more about what was going on or had some advice from a knowledgeable mechanic - which I certainly ain't! (grin) It shouldn't have that much end play in the crankshaft though, I'm certain of that.

IH3444 · Oct 6, 2009

Possibly Broken crankshaft. I have seen this before in other non chinese engines. It will knock as you say, have huge endplay, and still run. You should drop the oil pan and investigate. I used to work at an engine remanufacturing facility in a previous life. So I have seen a lot of engine damage before.

Affordable · Oct 6, 2009

They do use thrust washers on these engines, I would take a closer look before you do alot of damage

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

IH3444 · Oct 6, 2009

Could also be something as simple as just the flywheel comming loose. Pull the starter and see if you can wiggle the flywheel. If this is a small machine, you may just split it in two, and check it. Sounds like a lot of work, but really isn't. If it is the flywheel, some blue lock tight on the threads, and retorqueing should fix it up. Good Luck!

Johnny P · Oct 7, 2009

Hello,

Thanks for the info. Just started to remove the engine to investigate fully. It's all a new experience for me, this mechanicing lark. I will let you know how I go on.

Johnny P

Johnny P · Oct 18, 2009

Hello all,

Removed engine abd stripped down. The crankshaft has broken across one of the counterweights, Don't know why, maybe a fault in the casting!

Johnny P