ZT1 PTO clutch - Overheating common?

[wheedwhacker]

Just lost the PTO on a 3 yr old ZT1 54" while mowing on flat, stable ground. Putting it in the air, I see the wires looked like they were cleanly cut. Looking closer, it looks like things got melted and sure enough, the PTO clutch itself was almost hot enough to cause burns.

I've never dealt with these electric PTOs before but looking at some of the language on replacement parts, it appears this might be a common issue...??

Pretty expensive part to be burning itself out regularly if thats the case.

[R Bedell]

First, welcome to OCC..........

The wires, were they cleanly cut or melted ???

[wheedwhacker]

Thanks for the welcome.

They look like they've been cleanly cut but something appears melted below the connector.

I took the pic quite a bit after discovering the cause and noodling around to see if it was just that the wires pulled or broke free. The cleanliness on the green could be from me messing with it. There is still wire present on both crimps that are still in the connector housing.

Quite a bit of heat on everything except the belt & PTO pulley. The bolt at the bottom was especially toasty.

[R Bedell]

Looks like something "slapped" the wires to break them that clean. Looks like .250" Female QD Crimp Connectors. Install some new ones and plug into the PTO terminals. See what happens and report back.

[ironman]

I would think if excessive heat caused the problem, your connector would be melted.
From what I can make out in your picture, yours looks to be in pretty good shape.

[wheedwhacker]

Well that was fun.

Don't have any of those male spade connectors so I managed to salvage them out of the housing.



Fired it up and got about 2 seconds of PTO engagement. Checked connection and all looked secure but couldn't get it to engage again.

Might try again without the connector housing and fresh spade connectors. (Had to hack them together, could not remove all existing wire & recrimp, slapped some sloppy solder between the two instead.)

If no go again, do have replacement clutch on hand.

[wheedwhacker]

Originally Posted by ironman

I would think if excessive heat caused the problem, your connector would be melted.
From what I can make out in your picture, yours looks to be in pretty good shape.

Right. What caught my eye was the bits below the connector which is what I thought was the connector at first. Not until posting did I realize where it was.

Very odd location in the yard for something to have slapped them clean like that. Nothing there that I know of but that does look to be what happened.

[R Bedell]

Those Female Spade connectors are available at any Auto Parts Store. The 14-16 Gauge (Blue) is the type you need.

[wheedwhacker]

Pulled the connector back out & double-checked that it had good contact. Resoldered just to be sure. (Former avonics tech & did car stereo/tv repair in HS.)

Checked voltage from switch, 14.4v, 12.1 w/ engine off.

See pic for charred bits below PTO connector I was referring to.

Also found busted off chunk of crank keyway (in pic below connector) which shows rust all round so its probably been busted since manufacture.

Pretty close to only being 3 yrs old so will be checking warranty now.

My 1st Cub. Not overly impressed.

[wheedwhacker]

3 months, 3 weeks and 1 day out of standard warranty. Started extended warranty process, guess we'll see.

Didn't spend a lot of time reviewing & documenting yesterday but kinda put things back together as best as I could just now and took more pics. Seems a bit more material missing from keyway than the chunks I found and seems a good bit of it rusted into dust.

Manually spinning the PTO clutch, it grinds a tiny bit and lightly binds in spots. Pretty sure that would create a bit of heat, though maybe not the bulk of it.

I'm no expert but looks like someone didn't make sure the PTO was lined up and fully seated in the keyway before breaking out the impact driver.