MTA/400/450 and 560 parts interchangeability

CenTex Farmall

Well-known Member
Being that early 560's came with the band type PTO and later changed to the clutch type, can one install a clutch type PTO in 450
and lower machines? I see that the mounting bolt pattern is the same but what I don't know is the length/spline count on the front
end.

Is it also possible to install the PTO speed reduction gears from a 560 into the 450? Would one need just the gear set or the
intermediate shafts as well?
 
Rear unit will fit and existing rear shafts to drive the PTO the same for both types. Since the clutch type has no gear reduction like the planetary the front gear sets turn the PTO input shaft at a slower speed in a 560. Because of the 560 higher RPM even the 560 with planetary has a higher reduction front gear set for planetary than a 450. That gear set would get the closest. Larger lower front PTO drive gear on a 560 used a deeper cover under the gear than a 450 and I think also you would run into clutch housing clearance problems installing the lower shaft 560 gears in a SMTA to 450. Figured up how much higher the PTO RPM would be when putting a clutch type in a 450 in the past if I installed one with no other changes but don't remember now. Would work for some light work if remembered to not rev full throttle, but for full power tasks it would over speed PTO shafts and machines.
 
What I'm investigating is turning up the RPM on a warmed up 450 for more HP but wanted to keep the PTO in the correct operating range by swapping gears. I have several 450/400/MTA whole tractors and pieces to work with but no 560 parts.

I wasn't sure if the band type embodied some reduction in the planetary set or if they were using the planetary features simply for the ability to create IPTO. Do you remember what the ratio in the PTO unit itself was? I know where there's a junk 460 with a clutch type PTO.
 
Think the planet PTO input turns 1.44 to one turn of output. Least that's what I figured in the past. Front drive gears SMTA to 450, 25 to a 47 tooth. 560 planet PTO 22 to a 51 tooth. Clutch type 21 to a 70 tooth. 660 18 to a 55 tooth. If I figured correct a 400 a 1450 RPM would turn a clutch type PTO at 771 RPM. With 22 -51 gears 629 RPM at 1450. With 660 18 and 55 541 at 1750 RPM. Need 1800 rpm for 540 RPM with the 21 and 70. 660 may be the best for what you want but the fewest around. Know the 70 tooth gear needs the deeper cover under it and never tried one up in the clutch housing to make sure it would clear. At on time I was considering using a 560 housings and internal hydraulic pump on a SMTA and trying to match speed of hydraulic pump drive and PTO. Decided not to change the SMTA.
 
Yeah, at some point it becomes simpler to just buy a 560 and they're not terribly hard to find in this area.

Looks like the best bet would be to stick with the planetary pto and use reduction gears from early 560. I'm looking for around 65 HP and I think it would have adequate durability for my uses.
 

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