M4030 rod bearing

ajv2

New member
Oct 19, 2011
7
0
0
flemington,nj
i bought a used M4030SU from a dealer for $5000
had it less than a year, used it to cut grass last summer
started to cut this year ; new oil and filter just done
a abd knock started; dealer said rod bearing went
quoted $7500 to fix
does anyone know anything about this model;
 

Kubota Newbie

Active member

Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
Dec 28, 2010
533
81
28
Mount Vernon, Ohio
At this point it doesn't much matter what oil he was using. Anyway, the only time I've ever seen a rod bearing failure that was actually caused by the wrong oil was in a splash oiled engine where a heavier than spec oil was used and it didn't flow well enough when cool to lube the bearing. Otherwise, bearings are really forgiving. Usually it is an oil delivery issue that causes rod and main bearings to go suddenly (actually that was the case in the splash oiled engine too).
Assuming they've pulled the pan and actually looked at the bad bearing I'd want to see it, and the crank pin it was on. I'd also want to know what the measurements on the pin were and how far out of spec it was. 7,500 sounds plenty steep, actually it sounds like they just don't want to do it. You're basically looking at removing the engine and doing a complete re-build. unless the pin is still good enough you can polish and put a new bearing on it. I'd get an opinion/price from an independent tractor shop if you have one around. Having the crank ground will probably add around $300 to the price of a normal re-build.
 

Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
0
16
Tacoma, WA
Huge bummer!

Someone else just went through a situation where they installed a Wix filter that was supposed to cross, ran the engine, and found the filter had no oil in it. Apparently the filters that are supposed to be the same aren't...

Not sure what you used, but the situation sounds similar. In his case, he got lucky, changed the filter and went on his way.

I would figure out which cylinder it is, drop the pan and inspect.

Keep in mind a bad injector can also cause a knock sound...

Good luck,

Steve