Vermeer baler drive help

I have asked a number of mechanics and have not been able to get any clue on an issue I am having with my new to me 605 super m with 9000 bales.  I am hoping someone here has run across this.

 

When I got the baler, I replaced the cross drive shaft gear, the start roller gear, the idler gear for them, and the upper belt drive roller gear as well as all the chains for the entire baler.  I baled 40 bales with it.

 

When baling, I had a plug.  After unplugging it, I had the tailgate open while running to confirm everything was working OK.  I could hear a "clunk" ever 30 secs to a minutes.  When I opened the left side door, I could see the chain driving the start roller was loose on the bottom and tight on top where the idle sprocket is.  The sprocket was tight against the stops and the chain was loose on the bottom and riding up the cross shaft sprocket.  Every 30 seconds to a minutes, the chain would jump the sprocket and skip forward a link causing the clunk sound.  When I start to close the tailgate, the chain returns to normal operation. (tight on the bottom and the idle sprocket returns to normal position)

 

While experimenting with it, I realized the tailgate position seems to have no effect on the issue.  If seems to be more dependent on if the hydraulics are opening or closing the tailgate.  If I start to close the tailgate regardless of current position, the chains will run normal.  If I start to open the tailgate regardless of current position, the chains will run slack on the bottom.

 

Looking at it while it run, it almost appears the gear on the starter roller trys to pull the chain faster than the cross drive shaft gear is driving when the hydraulics open the gate a little.  They seem to be fighting each other but only after the hydraulics lift the tailgate.

 

It has been suggested I look for bad bearing on the belt rollers but I have not been able to find any.

 

I am including a picture of the chain when it is working correctly (hydraulics close the tailgate) and when it is not (hydraulics lifted the gate slightly)

Notice the idler sprocket position against the stops and the slack in the lower chain.

 

I am out of ideas and am hoping someone here can point me in a direction to fix this.

 

 

 

 

Vermeer baler drive help