JD 350C weak pushing power

[Acepilot]

I have a 350C and while it is cold it will push fine, but once it gets hot it has no pushing power and will stop moving. The engine is strong and runs great. Reverse is good at any temp, just forward. Unit has a shuttle shift tranny. All fluids are full to level.
Thanks for any help.
Tom

[KenP]

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