PTO Noise F600 73 grain truck

[Tree-Farmer]

I went to use my grain truck and it's making a funny noise.

When I put the PTO in gear and let out the clutch, it made a loud, unusual noise, hard to describe.
1973 F600 grain truck, worked 6 months ago, I could raise the bed before. Has a 330 motor, 4 speed transmission, 2 speed rear axle.
The noise happens when the PTO is running, I didnt try to raise the bed.

What can be wrong with a PTO?

I assume I need to check the oil in the transmission. How do you check the transmission fluid in this truck?
Does the PTO use the same reservoir as the manual transmission?

What else could it be? Thank you for any comments!

 

[used red MN]

Did you look at the shaft? Did it get bent or is something rubbing on it, are the joints tight? There is a pipe plug in the side of the transmission to check the gear oil level, will be square head or will take a 1/2 or 3/8 drive ratchet. If it being low was an issue it would scream all the time because the trans bearings would be dry as well. The oil in the hoist pump could be low as well, hydraulic fluid. Tough one to check if the hoist does not raise. If you do raise it and check the fluid there should be a safety lock to hold the bed up. If not at least throw a couple 4x4 or 6x6 blocks back by the hinge as an emergency stop.

 

[Steve@Advance]

The PTO is a simple bolt on accessory.

Do check the transmission oil first.

Look things over, check that the PTO bolts to the case are tight.

If the hydraulic oil in the lift is low it will make a growling noise and the lift will only go part way up, or not lift at all.

 

[Hobo,NC]

On my 77 its a square pipe plug it takes 5/8 open end wrench. The plug is rear of and high of the PTO on the right side. NP435 trans I think. Yes the PTO becomes part of the trans and uses the same oil sump.

 

[Bob N.Y.]

Could it be a loose u-joint in the shaft?

 

[caterpillar guy]

Since it was working before I would say you could rule this out . But did they shim the PTO right when they put it on. Yes they actually use different thickness gaskets for shims to keep the lash in the gears right. IF it was not done right it can do all sorts of bad things including break the trans or PTO case if reved up with the throttle. The reason I let them just idle to get them up. otherwise I would guess it has to be something already said. Unless if you have those dumb cable operated PTo then it could slip on the cable so it would just grind on the gears instead of going into gear.