machine was smooth as glass. out of no where started strong shake . new motor mounts got installed that day previous excavator did exact thing and it was mounts . new mounts still has shake seemed more fast shake not as violent. mechanic said could be coupler. anouther said seems like injector. cracked all 4 injector fuel lines each made noticeable miss. I say there good then? replaced fuel filter no change . so first any ideas to further check ? was gonna check turbo in am . no out of normal smoke little white when reved from idle to 10 but stays clear . notice potential power loss might be just in my head . 2nd does anyone know how to test fuel pressure from injector pump ? and is there a way to check coupler without pulling pump ? and 3rd does anyone have a shop manual for removal of coupler and fuel pressure test? thanks again guys 6Gk00390 s/n also machine is still operating daily.
Find any hole in the housing and look to bottom for debris. Starter hole, speed sensor hole, etc..
The drive coupling is a wear item, and, when I had my 312, it always vibrated the trim and panels at speed dial 1&2, but never above that. My 314s (c,d,&e) all vibrate the same.
I have another 312 and it has always had a vibration at 1and 2 as well even after new engine was I stalled but smooth operating. This 312 was smooth one 1 the.n just started shaking . Can visibly see engine shaking
My hunch matches theirs...drive coupling coming apart. I've seen just the rubber disintegrate, and I've also seen one of the triangle lugs shear off. Visual inspection is the only option. If you can't see thru an existing hole, you can always thread longer bolts into the flywheel cover, in lieu of the stock ones, and pry the flywheel cover out enough to look for pieces/ debris at the bottom of the housing. Only need 0.5 inch to look at bottom for coupler debris.
Check out my post , I had similar problems . I think it was “ engine has a miss or seems to”
Been offline for a while. A update is I still have not got to the coupler scared of removing pump without a shop manual. I started looking into it again noticed a little fuel leak on a return line into a banjo on the block tightened hose and I think it may have improved but I can be positive . It does still have the shake and also I notice if put on 2 theres a tick of some sort could be something loose wobbling hitting metal but I do not know . I'm in work of finding a shop manual .... also it's not "crisp" when moving throttle positive numbered until about 8 to 9 -10 . How can I check fuel pressure or air in the fuel system? I have fuel pressure gauges master compression gauges but.no hydraulic psi gauges . If pump removal is easy enough to do that it can be easily typed I can try before I find a manual . Thank you to all