[Dan 2N]

One of the projects I need to do this winter is rebuild the PTO clutch in my Gravely 816, as I understand there are different color coded springs for the clutch cone , I will be using the Gravely jig to take the clutch apart but can someone tell me something about the color code and how to use it.
Thanks in advance
Dan 2N

 

[arcam8123]

The springs are color coded blue and red. One is 750lbs and the other is 1000lbs. I think in that order, but I would wait for a second opinon.

 

[Jimmy in NC]

I'm pretty sure Ron is right.

This is the inside of my 816S with the early Blue Spring.

 

[gravelymay]

Blue 750 LBs.
Red 1000 Lbs.

 

[Richard-tx]

The disadvantage of the 1000 lb spring is that it makes it almost impossible to ease the clutch into engagement. The advantage is that if adjusted correctly, the clutch is much less likely to slip under load.

 

[yamato72]

In my opinion, put the red spring in now while you are doing the clutch lining, and make it less likely that you'll have to service that PTO clutch again in the future, after the supply of parts has dried up.

 

[Richard-tx]

In my opinion, put the red spring in now while you are doing the clutch lining, and make it less likely that you'll have to service that PTO clutch again in the future, after the supply of parts has dried up.

I agree.

Having said that, if the clutch does go NLA there are ways to rebuild that clutch. None of them cheap. One way would be to use a brass lining. While not as good as the Raybestos friction material, brass seems to the next best choice in friction material. Applying the brass to the steel would likely require that that brass be plated on. Gluing the lining on may be possible. Drilling and inserting brass plugs would require a CNC machining center and be cost prohibitive..

Brass clutch linings were used on certain fork lifts and they would last for at least 20 years provided that the oil bath pump kept working. If the pump failed the clutch would last about a week. Since the Gravely clutch is splash lubricated no pump is required.

 

[Fla Don]

The disadvantage of the 1000 lb spring is that it makes it almost impossible to ease the clutch into engagement. The advantage is that if adjusted correctly, the clutch is much less likely to slip under load.

Operator skill Richard, operator skill.

 

[Dan 2N]

Thanks to all, loks like I will go wth the strongher spring, don't want to need another clutch anytie soon, this tractor numbers check out to be for 1978.
Thanks for the help, :thanku:
Dan 2N

 

[popcorn popper]

Operator skill Richard, operator skill.

If you ever had the chance to run a GMT 9000... the PTO engagement lever is much longer for ease of operation. But the neat thing is that it sets low in the shifter plate about the same position as a regular PTO level, but the rod slides up tall to provide leverage to engage/disengage.

I know the GMT 9000 has a different extremal PTO Clutch. It's like a smaller version of the FWD/REV cam clutches. But the design and operation of the lever could easily be applied to operate the heavy PTO spring.

Tom

 

[Fla Don]

If you ever had the chance to run a GMT 9000... the PTO engagement lever is much longer for ease of operation. But the neat thing is that it sets low in the shifter plate about the same position as a regular PTO level, but the rod slides up tall to provide leverage to engage/disengage.

I know the GMT 9000 has a different extremal PTO Clutch. It's like a smaller version of the FWD/REV cam clutches. But the design and operation of the lever could easily be applied to operate the heavy PTO spring.

Tom

The 24-G with external clutches isn't hard either. The 35-G is a bit harder but then again, it has a heavier duty clutch.