1978 JD 4400 rotary screen conversion question

[steveinohio]

I have a 1978 JD 4400 combine with 329 diesel engine. Has the rotary screen on the right side of the engine that came out I believe in 1974. I have seen the different type of rotary screen on a couple of 4400's that is used on the 4420 combine. Just curious, how much time and effort would it take put put a 4420 rotary screen on a 4400 such as mine? Any assistance is always appreciated.
 

[JD Seller]

What you are seeing is the 1979 model 4400. They would be serial number 350,000 and up. They had the flat rotary screen factory installed. The JD 4420 combines did not come out until 1980. I never really got a straight answer from any one at JD why they ran the 4400 another year.

As for adapting one to an older 4400. The side skirt is different and the drive for the screen is like the 20 series. So you would need to find a donor 79 model to be able to do it without major fabricating.
 

[steveinohio]

Thanks for the reply. Would a flat rotary screen from a 4420 fit on my 4400?
 

[JD Seller]

Not without major fabricating and a donor combine. The drive is different plus the sheet metal around the radiator.
 

[WGM]

Wouldn? It be easlier to update to a newer machine?
 

[steveinohio]

Wgm, thanks for your reply. That is certainly an option. The thing is my 4400 just turned 3,600 original hours and I keep it maintained the best I can. I wouldn't mind having a 4420 with equal or lower hours than mine.