JD 4600 Yanmar 4TNE84 engine rebuild problem - Crankshaft balancer

[desmetde]

My John Deere 4600 tractor (2000) equipped wit a Yanmar 4TNE84 engine threw a connecting rod. I ordered a 4TNE84 short block to swap out. During the engine disassembly I find something very interesting that I cant seem to get an answer on.
The original engine has a crankshaft balancing unit that sits above the oil pan, driven by a gear on the crankshaft. The short block I bought doesnt have this gear on the crankshaft. It appears the oil passages are modified as well.
Did Yanmar change to a harmonic external balancer?
Can I still use this short block without the internal balancer?
has anyone seen this?
Thank you, Dan

 

[jthibodeau89]

In 4cyl automobile engines the internal gear drive balancers are used to cancel out second order harmonics and are geared to 2x engine speed. Sole purpose is to reduce the vibration felt by passengers. Not required for crankshaft torsional harmonics. The engine still has a classic harmonic balancer for torsional vibration. Not sure why a tractor diesel engine would have this type balancer. Must be a Cadillac ride.....

 

[desmetde]

My John Deere 4600 tractor (2000) equipped wit a Yanmar 4TNE84 engine threw a connecting rod. I ordered a 4TNE84 short block to swap out. During the engine disassembly I find something very interesting that I cant seem to get an answer on.
The original engine has a crankshaft balancing unit that sits above the oil pan, driven by a gear on the crankshaft. The short block I bought doesnt have this gear on the crankshaft. It appears the oil passages are modified as well.
Did Yanmar change to a harmonic external balancer?
Can I still use this short block without the internal balancer?
has anyone seen this?
Thank you, Dan

See the attached photos, with labels

 

[desmetde]

J Thibodeau, thank you for your reply. i attached some pics below, so your opinion is that I dont need his balancer?

I wish I could find a John Deere dealership that even knew what I was talking about.

why would one engine have it and another not? when they are the same engine model?


Dan

 

[Tx Jim]

JD begin utilizing engine balancer box 60 yrs ago on model 3010(see photo). Then in '65 the engine utilized in the utility tractors with 4 cylinder engines had balancer shafts. Some of these same utilty 4 cylinder engine utilized in other applications had no balancer shafts.

 

[desmetde]

this engine is a 2000 year model, do you think im safe to use the short block without the balancer unit?

 

[ruffdog]

Maybe the replacement engine was for a generator or another application where vibs don't matter? A letter or number at the end of the model might mean anti-vib or not.

 

[ruffdog]

There is a model 4TNE84 AF, EAF, GB2B, and maybe others. This site listed parts and the crank was not to be used on balancer engines. (note 3 at bottom)

Yanmar 4TNE84 | Maxiforce

 

[jthibodeau89]

J Thibodeau, thank you for your reply. i attached some pics below, so your opinion is that I dont need his balancer?

I wish I could find a John Deere dealership that even knew what I was talking about.

why would one engine have it and another not? when they are the same engine model?


Dan

Those pics look just like the balancer we put in the 4cyl auto engines. The engine without balancer will definitely shake more. This type of crank driven balancer is the only way to get rid of 2nd order vibration. The gear must be phased correctly with the crank when installed. The crank couterweights and spin balance (1sr order) are the same.

Mechanically the replacement engine will run just ginr without the gear driven balancer. But you eill feel mpre vibrstion. Does the replacement block have all of the required mounting holes?

 

[desmetde]

Thank you once again, not sure about the mounting holes yet, so far looks exact