allis chalmers 5050

[Rob VA]

question . the pto clutch shifter knob to the left of the trans shifters . is that suppose to be up or down when not using the pto?

 

[Harry in Ky]

Down. It should be down whether using the PTO or not. It should only be up when shifting the PTO lever in or out, or to momentarily stop the PTO while it's in operation. That lever is basically like the clutch pedal. You push it down while shifting gears or inching the machine, then the pedal comes up and stays up.

 

[Rob VA]

Ok i just got this tractor its showing 1800 hrs and this lever whats up . previous owner says he just used it to cut golf course with .idk . not sure if this is a bad thing or not.

 

[Rob VA]

Trying to figure out the in and out of tractor. my first AC . please bare with me . lol

 

[Harry in Ky]

Your choice. I'm merely stating that the lever should be down when not actually in use. Simple as that. It's not designed to be the on/off switch for the PTO. Only to disengage the PTO portion of the clutch while shifting the PTO in or out of gear. There is a lever on top of the transmission housing just below the seat for doing that. At one time there was a sticker near it explaining that but it's no doubt long gone.

 

[Rob VA]

OK im going to put it down from now on. thanks for the info Harry.

 

[AntiqueTractorFan]

The 5050 is one of the FIAT built tractors. Oliver, White, Cockshutt, MM, Kubota, Long, and Hesston (and others im sure..) all sold pretty much the same tractor with mostly just cosmetic differnces. I personally own a 1265 Oliver, which I believe is a size smaller than a 5050. I'm sure there are others here that are much more knowedgeable on the topic who can give a better description than I what I can.
If I'm understanding this right, yes, that lever should remain down at all times besides when shifting the PTO on/off, or to momentarily stop it, as it is the PTO clutch. One of the main killers of these tractors was people leaving the clutch lever up all the time, which would basically act as riding the clutch and will rapidly wear the throwout bearing and thrust bearing on the crankshaft because of the added pressure.

 

[AntiqueTractorFan]

This should be a similar diagram to what you have.

 

[rrlund]

Absolutely definently down. Leaving it up wears out the thrust bearing on the crank.

 

[Harry in Ky]

Absolutely definently down. Leaving it up wears out the thrust bearing on the crank.

You've been around these tractors for a long time I assume. The two stage clutch used in this model is similar in design to a great many other models built by Fiat over many years. Most of the earlier ones like this used similar PTO clutch lever operation. On many tractors built after that (I'm talking the New Holland versions) they used a similar clutch and throw out bearing configuration, and (I assume) a similar Iveco engine. Except the PTO portion is a sort of "bass ackward" design whereby the PTO disc is normally disengaged (disc floats free) and when the PTO is turned on the clutch becomes engaged keeping the throw out bearing turning the entire time the PTO operates. This obviously applies thrust pressure against the crankshaft and those same thrust bearings. It seems to me that would require at least wider bearings with more contact surface or possibly even a provision for more lube oil in that area. I'm not aware they ever did that, but maybe I just missed it. Any thoughts?

 

[Bob Bancroft]

You've been around these tractors for a long time I assume. The two stage clutch used in this model is similar in design to a great many other models built by Fiat over many years. Most of the earlier ones like this used similar PTO clutch lever operation. On many tractors built after that (I'm talking the New Holland versions) they used a similar clutch and throw out bearing configuration, and (I assume) a similar Iveco engine. Except the PTO portion is a sort of "bass ackward" design whereby the PTO disc is normally disengaged (disc floats free) and when the PTO is turned on the clutch becomes engaged keeping the throw out bearing turning the entire time the PTO operates. This obviously applies thrust pressure against the crankshaft and those same thrust bearings. It seems to me that would require at least wider bearings with more contact surface or possibly even a provision for more lube oil in that area. I'm not aware they ever did that, but maybe I just missed it. Any thoughts?

Good question. I have a NH TT60A (Fiat) I bought with 300 hours. And I have a NH TN55 (Fiat) I bought with 1800 hours. Handy, simple little tractors. The PTO levers almost act like there's some "over center" action, but I can't tell for sure. I hope I never find out! I am reminded of the JD 2510- the PTO control on them was definitely an "over center" mechanism. One of AC's last gasps was building the 6060-6080 tractors with Fiat drive trains. They were notorious for ruining engines when directions were ignored and the large PTO clutch lever was pulled back and left there.

 

[Rob VA]

yes the pic is what i have and thanks guys for the important info . the lever is down as we speak . i just hope the previous owner didnt run with it up all the time. . i guess we will see... when in doubt ask questions. im changing the fuel filters now . and see if we can get this thing started...im sure ill have somemore questions. bare with me as go this process. thanks

 

[rrlund]

If that's the same animal as my 1365 Oliver, and I think it is, they have an odd clutch set up. The PTO clutch runs against the flywheel and the main tractor clutch is inside of the pressure plate. Just the opposite of most.

 

[Harry in Ky]

Good question. I have a NH TT60A (Fiat) I bought with 300 hours. And I have a NH TN55 (Fiat) I bought with 1800 hours. Handy, simple little tractors. The PTO levers almost act like there's some "over center" action, but I can't tell for sure. I hope I never find out! I am reminded of the JD 2510- the PTO control on them was definitely an "over center" mechanism. One of AC's last gasps was building the 6060-6080 tractors with Fiat drive trains. They were notorious for ruining engines when directions were ignored and the large PTO clutch lever was pulled back and left there.

That's true, the 6080 and 6060 were indeed notorious for that problem, but the AC engine they used had next to nothing for thrust bearings compared to the Iveco.

The "over center" action you mentioned on some of the New Holland models was all in the lever/linkage design. There is nothing over center about the clutch itself. Merely a free floating clutch plate that's "released" when the PTO is not in use, and applied (engaged) when the PTO is turned on. Most all of the earlier 5000 series John Deeres used a similar principal with apparently good success because thrust bearing failures there get little or no reporting, at least to my knowledge.

 

[Bob Bancroft]

That's true, the 6080 and 6060 were indeed notorious for that problem, but the AC engine they used had next to nothing for thrust bearings compared to the Iveco.

The "over center" action you mentioned on some of the New Holland models was all in the lever/linkage design. There is nothing over center about the clutch itself. Merely a free floating clutch plate that's "released" when the PTO is not in use, and applied (engaged) when the PTO is turned on. Most all of the earlier 5000 series John Deeres used a similar principal with apparently good success because thrust bearing failures there get little or no reporting, at least to my knowledge.

So there must be some very robust thrust and "throw out" bearings involved. I guess it's a "throw in" bearing?!
AC had a fix for the 6000 series tractors which was a bracket installed on the front of the engine with a greaseable tapered roller bearing. So then you had a massive thrust bearing!

 

[Harry in Ky]

I'm well aware of the fix. I installed a few of them when the update came out.

 

[Bob Bancroft]

I'm well aware of the fix. I installed a few of them when the update came out.

As did I.