Vermeer 604 L Becomes Hard to turn

OK First post, hope I do this right.

I have a Vermeer 604 L and as bale forms it chokes 100 hp tractor down when reaches about 5 ft + bale.  

It has new teeth and new belts last year rolled about 600 bales total last 2 years since installing.  I have owned baler for 5 years or so and it has been

like this from beginning. I have checked the belts and they are routed according to manual.  I have checked the chain drive and it is routed according to

the diagram on the side of the baler.  The beginning density or air bags are set line between 2 & 3 or blue green which is almost

minimum to start a bale.  By the time hydraulic bale density reaches 4 or pretty much straight and 5 ft  it will  choke tractor down.  I baled last year with 85 hp tractor

and it did it.  This year I baled with 100 hp tractor and it did it. When I put new belts on last year checked all roller bearings out all ok. .  Really do 

not know what else could be except a bearing in a chain driven roller but how could a bad bearing last through this long and not

make noise or show up when running at idle or before a bale reached 5 ft stage. I have been stopping when tractor starts choking  down and have pretty much ended with 5 ft bales.

I would like to make maximum size 6 ft bale as I transport 75% of my hay to home farm and would like to minimize trips.

Any suggestions comments appreciated

 

Vermeer 604 L Becomes Hard to turn