JD 655 starter turns over slow / won't start in cold weather

[toddbe]

Now that the weather has turned cold my 655 starter turn over very slow - as if the battery were dead. I have a new battery installed. Even turns over (or tries to turn over) with the a larger battery starter attached. I have replaced the starter, but still the same response. In the summer the engine / starter operate fine. As the temperature gets colder it gets worse. I have a coolant engine heater installed. Any idea's? Is there a heavy duty starter for this?

 

[oosik]

Welcome to TBN. Just a thought - what weight oil are you using in the tractor? Is there a pto somewhere on the tractor that is still engaged during the start cycle?
Sound like somewhere there is an oil or grease that is not responding well to the colder temps.

Another thought - check that the ground from the battery is still making good contact wherever it is attached.