Ford 1920 will not work under load

[Rayzor007]

I changed the trans/hyd fluid in my Ford 1920 along with new filters, both hydraulic and fuel. Since then the tractor will not operate properly under load. The tractor will not even move in 4th(high) range and will not push into a soil pile in 1st(low) range. The engine continues to rev normally and the hydraulic attachment (front end loader) operates normally. What did I do to my previously dependable unit

 

[fried1765]

I changed the trans/hyd fluid in my Ford 1920 along with new filters, both hydraulic and fuel. Since then the tractor will not operate properly under load. The tractor will not even move in 4th(high) range and will not push into a soil pile in 1st(low) range. The engine continues to rev normally and the hydraulic attachment (front end loader) operates normally. What did I do to my previously dependable unit

Maybe totally unrelated to your filter changes.
How many hours on the tractor?
How many hours on the clutch?

 

[Rayzor007]

tractor has 3940, Clutch rebuilt last winter, less than 50. Gear changes without issue. Front end loader works so I assume that eliminates nay hyd pump issues?

 

[fried1765]

tractor has 3940, Clutch rebuilt last winter, less than 50. Gear changes without issue. Front end loader works so I assume that eliminates nay hyd pump issues?

I don't mean to beat the clutch issue to death....but.....
I put a NEW (aftermarket) clutch in my 1920 last year.
The NEW clutch lasted for about 5 hours.
2nd split, showed one of the (new) clutch fingers had failed.
The fact that your gears change without issue though, does make it seem that your problem is NOT related to the clutch.

 

[jmc]

I had to bleed the fuel line on my 1920, whenever I cleaned or changed the fuel filter. I don't know if that would still be an issue though, once you get it started.

 

[Leejohn]

Clean the air filter