Don Terrill’s Speed-Talk

Just picked up a Clark off-road forklift for the shop the other day that needs engine work

Any ways I just pulled the engine tonight and found the crank broken right behind #1 journal

Along with 1 balance shaft gear ground up from a loose shaft bushing and the balance shaft drive gear missing a few teeth

Is this a common problem with this style engine?

It was previously rebuilt by Grindstaff engines so everything else looks fairly new
They must not have crack checked the crank before installing
You can clearly see it was cracked for a while.

Forgot to mention it's Lpg model

I think intermittent firing during shutdown or startup from lack of maintenance will produce spikes that concentrate forces in these areas (likely high reverse torsion forces). On the 300 SDL (automotive) I think it was also the reason for the high failure rate of the serpentine belt tensioner.

Chipped tooth wrote:Just picked up a Clark off-road forklift for the shop the other day that needs engine work

Any ways I just pulled the engine tonight and found the crank broken right behind #1 journal

Along with 1 balance shaft gear ground up from a loose shaft bushing and the balance shaft drive gear missing a few teeth

Is this a common problem with this style engine?

It was previously rebuilt by Grindstaff engines so everything else looks fairly new
They must not have crack checked the crank before installing
You can clearly see it was cracked for a while.

Could have been from fan belt being to tight seen it many times crank breaks on #1 because crank is being pulled up wards by to tight of a fan belt shaft is turning off center and breaks