Farmall 450 Torque Amplifier

[RyanKve]

Hello all,
Recently I purchased a Farmall 450 diesel. After slight repair I was able to get it running on gas and diesel excellently. The tractor makes gobs over power, however it is having issues with the clutch and T/A.
In fifth gear it slips and wont move with the t/a forwards. However if I pull it back it will grind but if I push in the clutch it will stop grinding and move. Mid throttle it will do fine but if I rev it up the clutch will start slipping. You can feel it lightly grab again when throttled down. Going up a hill is impossible in fifth gear. 4th gear will slip only if starting on a big hill. The tractor will not get moving if ta is forwards.

All of this is after I tried playing with the linkage. Here is what I did. I started by disconnecting springs and rods that went between clutch and t/a. Adjusted clutch freeplay to about 3/4 inch. From there with the t/a handle forwards, I twisted the shaft going into the t/a housing gently counter clock wise until it stopped. The linkage didnt have enough threads in order to the the 3/16 gap in the buckle. My guess is it maybe had double that. I then adjusted the linkage between the clutch and t/a to the shortest possible length.
It does leak a little oil out from the bottom of the clutch.
Im new to the t/a but not the clutches. Ive split 2 Hs and a 2404 for clutch work. Im not afraid to split it but wondering it anyone has suggestion first.
Thanks, Ryan

 

[used red MN]

In the link take off cover 8. Not a lot of room in there but tell us what you see or post pictures. Start it and put it in gear and pull the TA back. Does that part in there stop turning? If is keeps turning your low side TA is out, which I am already fairly certain it is. The small dry clutch in there drives the tractor in direct, if it looks like that the lining all flew off the plate that is why you start slipping in higher gears. And since the low side one way clutch is out that does not hookup to drive it through the reduction gearing. It could also be the main clutch is out. Interesting that when you pull the TA back and push the clutch that it stops grinding.. that part makes sense. When you say it moves, that does not make sense.
CNHI Farmall 450D parts diagrams

 

[BarnyardEngineering]

I don't know the TA adjustment procedure off the top of my head, but what you did doesn't sound right. There are a couple of older youtube videos on the adjustment procedure, because you can't quite go by the book due to wear in the linkage.

For sure the low side of the TA is out. If your high side is slipping it should take over and pull.

The oil coming from the clutch housing is also a problem. If there's enough to drip there's probably enough to get on the clutches and cause problems.

Now, if you don't want to do a full TA job you can replace the TA clutch, pressure plate, and throwout at the same time as you replace the main clutch, and that will get you the high side of your TA back.

 

[used red MN]

In my opinion getting the clutch and TA set exactly right in this case does not matter. I think you understood that the TA clutch shaft needs some free play in the Direct position which means it can be moved slightly in the counter-clockwise direction, meaning no force is being applied which might be partially disengaging the TA clutch. And also just like a regular machine the pedal clutch needs some free play. I have a hunch that the TA release bearing is very bad condition and making noise maybe even grinding metal to metal. If while pulling the TA back and the lever feels like it is pulsating this means some of the release fingers on the TA pressure plate have broke or their cast in pivot points have broke out. Also a common failure.
Edit to add: My reason for saying this is why spend any extra time adjusting it to the 9th degree when it has to come apart anyway. If it is actually usable without tear down then sure adjust it correctly.

This post was edited by used red MN on 03/15/2023 at 01:47 pm.

 

[Mrfred54]

Unhook both links for the TA.make sure you have free play for the main clutch and drive it. You will only have direct drive for the TA.remove the small tin cover on the top of the TA housing. You will see the TA clutch,pressure plate and throw out bearing.do you see anything unusual like broken fingers or the pivots for the fingers on the pressure plate. Bearing good?
Let us know after you drive it how it acted

 

[mrhud]

(quoted from post at 15:24:35 03/15/23) Unhook both links for the TA.make sure you have free play for the main clutch and drive it. You will only have direct drive for the TA.remove the small tin cover on the top of the TA housing. You will see the TA clutch,pressure plate and throw out bearing.do you see anything unusual like broken fingers or the pivots for the fingers on the pressure plate. Bearing good?
Let us know after you drive it how it acted

the one way bearing has gone bad in the sprag clutch

 

[rustred]

i will say your main clutch is done.

 

[mrhud]

(quoted from post at 19:13:31 03/15/23) i will say your main clutch is done.

i will go out on a limb and say that after you replace the engine clutch and the ta clutch it still slips

 

[used red MN]

MrHud what you said would likely be true of the Low or
reduction side of the TA. However, as Barnyard E said
in the last part of his post, with a main clutch and TA
direct clutch that are capable of holding and
transferring the power new or whatever the tractor will
drive like a normal 5 speed original non-TA tractor if he
chooses that route. I also agree by his description the
one-way sprague is likely out on his tractor.

Ryan I sent you an email.