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I have a John Deere 425 with a 60" deck. When engaging the PTO, the PTO light comes on, the shaft spins. The engine does not speed up as if there is no load and the blades barely creep. The belt is not slipping and all 3 spindles turn freely. I'm desperate and need help or suggestions. Thanks
 

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:wgtt:

You need a mechanically inclined person to look at the machine for you,, something is wrong,,

or,, swap the engine for something larger,, possibly a 1962 Chevy 409HP/409 ?? :dunno:

Sorry, I had to do that,,, :flag_of_truce:

:bigthumb:
 

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I have a John Deere 425 with a 60" deck. When engaging the PTO, the PTO light comes on, the shaft spins. The engine does not speed up as if there is no load and the blades barely creep. The belt is not slipping and all 3 spindles turn freely. I'm desperate and need help or suggestions. Thanks
What RPM are you running at when you initiate the PTO? and what RPM do you go to after the pto is engaged.. Full bore is expected when you are mowing even if you don't have a 409 under the hood as CADPLANS recommended! Funny guy that he is! :laugh:
The slow spinning of the blades has me baffled if you are at WOT.. :dunno:

What about the deck belt? Tension pretty good?
 

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If you are running the engine at a high speed or at WOT, and the deck is barely spinning, chances are the PTO clutch has worn out in the rear unit.

Another sign of the PTO clutch being shot is the least resistance on the blades will slow them down or stop them, such as pulling into real tall grass.

When the PTO clutch is slipping, the rear hydro unit will develop a lot of heat in a hurry and can actually cause the engine temps to increase and run hot because of the heating of the hydro oil and running the hot oil through the radiator oil cooler section.

If the engine is operating OK and the engine speed is normal and the deck blade speed is a problem, it's likely the PTO clutch.

If the engine speed is slow and you can't increase the engine speed, the deck speed would also be very slow. In fact, engaging the PTO clutch at too low of an RPM of engine speed can stall the engine.

So, we need to know, is it the engine which is running slow, causing the deck to also run slow (which it would do) or is the engine speed fine and the deck speed is super slow?


We need more specific details to help you.
 

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Your sure you haven't sheared a shear pin on the drive line somewhere and it has enough friction left to get the blades going around but not able to cut anything?
 

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:wgtt:

You need a mechanically inclined person to look at the machine for you,, something is wrong,,

or,, swap the engine for something larger,, possibly a 1962 Chevy 409HP/409 ?? :dunno:

Sorry, I had to do that,,, :flag_of_truce:

:bigthumb:
Yeah, I have had days like that where I just have to post such an answer, but I am not sure the OP appreciates the extent of and attempts at humor when they are faced with the problem.......But some of us do.....:good2:

The real question is, how does he hook the 409 / 409 to the Rear Hydro unit, with a Powerglide or manual 4 speed....?? Using the powerglide eliminates the clutch pedal fab requirements....:laugh: Getting the side panels to fit might be a bit challenging and closing the hood will also require some "custom fab work".....:laugh::lol::lol:

Now, we just need some clarification on his actual tractor problem, is it engine speed slowing the deck or a slow deck with normal engine speed? I can't really tell from the way he framed the question.......
 

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Your sure you haven't sheared a shear pin on the drive line somewhere and it has enough friction left to get the blades going around but not able to cut anything?
That tractor uses a shaft driven deck right from the mid PTO shaft and while there are pins in the driveshaft assembly, breaking one of those would be an all or nothing sort of issue. You either have deck rotation or you don't, from my personal experience.

Depending upon the hours on the machine and it's general service history, it could very well be the PTO clutch. I have replaced a few of those in that specific model of tractor over the years (in a 445 and a 455 which use the same rear end assembly from Tuff Torq).

If he has normal engine speed, my money is on the PTO clutch. If he doesn't have normal engine speed, then it could be a throttle cable, it could be a bunch of other things and it's going to take much more information to help him narrow it down.

If it is the PTO clutch, it's something which he won't want to attempt to replace himself if he doesn't have quite good mechanical skills and a technical service manual.

Here is what the PTO clutch looks like on that tractor, the last one I replaced was well outside the allowable tolerance levels and was down to plate on plate with no material. If my memory serves me, I think the maximum tolerance on the clutch plate wear was 0.106" or 2.7 mm. You can see from the picture where the actual wear was. This also means the fluid is contaminated with clutch material and the hydro filter is very dirty and possibly near being plugged if it hasn't been regularly serviced.

It still spun the deck but it was easily slowed down and tough grass would almost bring the blades to a stop despite the engine being at WOT.......

 

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Yeah, I have had days like that where I just have to post such an answer, but I am not sure the OP appreciates the extent of and attempts at humor when they are faced with the problem.......But some of us do.....:good2:

The real question is, how does he hook the 409 / 409 to the Rear Hydro unit, with a Powerglide or manual 4 speed....?? Using the powerglide eliminates the clutch pedal fab requirements....:laugh: Getting the side panels to fit might be a bit challenging and closing the hood will also require some "custom fab work".....:laugh::lol::lol:

Now, we just need some clarification on his actual tractor problem, is it engine speed slowing the deck or a slow deck with normal engine speed? I can't really tell from the way he framed the question.......
he would need to talk to a wheelstander guy so you reverse the tranny and rear end back to the drive train! You're welcome SB.
 

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Couple of other thoughts:

PTO brake stuck????

Passage that hydraulic oil that goes to PTO clutch is partially plugged

Pump is not putting out correct (high enough) pressure to totally engage the PTO clutch.

Most likely:

Worn out PTO clutch parts
 

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sounds like a burned clutch to me.
 

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I have a John Deere 425 with a 60" deck. When engaging the PTO, the PTO light comes on, the shaft spins. The engine does not speed up as if there is no load and the blades barely creep. The belt is not slipping and all 3 spindles turn freely. I'm desperate and need help or suggestions. Thanks
Well, it's been a week and the OP, 409/409, hasn't been back on the site since he posted the original question. Based upon the time he was last on, he didn't even see 95% of the responses he was "desperate for"..

And so it goes some times on public forums........:banghead: :dunno:

Hope he got the issue solved........
 

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Well, it's been a week and the OP, 409/409, hasn't been back on the site since he posted the original question. Based upon the time he was last on, he didn't even see 95% of the responses he was "desperate for"..

And so it goes some times on public forums........:banghead: :dunno:

Hope he got the issue solved........
On the other hand, he could have just visited without logging in. I do this sometimes when i'm in a hurry and am using my phone to check in.
 

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Well, it's been a week and the OP, 409/409, hasn't been back on the site since he posted the original question. Based upon the time he was last on, he didn't even see 95% of the responses he was "desperate for"..

And so it goes some times on public forums........:banghead: :dunno:

Hope he got the issue solved........
Yup but we lurkers, non mechanics appreciate the responses. It helps us learn if we ever encounter this type problem.
 
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