Weekend Freedom Machines banner

318 with strange PTO problem

755 Views 6 Replies 5 Participants Last post by  chuckv
Hi all...

I have a friend who has a 318 that has both of us stumped! After mowing for a while, he stops to take a break. After returning to the tractor, he cannot get the PTO to activate the mower deck. I've checked the switch; seems fine. I'm wondering if the electric clutch may have a short that appears when heated up, and clears up once it cools down a bit.
Anyone else ever experienced this? I've checked connections as well and all seem fine...


1 - 7 of 7 Posts
Tom: I would check the air gap around the electric clutch to see if it is w/n spec.
PTO gap? Maybe it changes when warm? Should be about 0.018" at all three slots.

I doubt that your air gap physically changes very much when warm, but difficulty in engaging the clutch at normal operating temperature <u>is</u> an indicator of too large a gap. As David said the spec is 0.018 inches (as shown in this excerpt from a manual)

You should also measure the resistance of the coil, which is nominally in the range of 3.5 to 4.9 ohms give or take... A much lower value indicates internal shorting of the winding, and that too can cause the clutch to not pull in at elevated temperatures.

See less See more
Thanks so much--I thought I may be on track regarding the coil resistance. Will check this out.

Thanks to all!!

See less See more
I have a 316 with the same condition.If you lightly tap the housing, it'll kick in. If the gap is too wide, how do you adjust it, or do you just replace it?
Charles (Stycks),

The picture above gives the very simple procedure to adjust the clutch in the text included. You can do this...the nuts with the springs under them are that are turned to change the gap. Be sure to get all three measurements set to the same clearance and check them all after you make the last adjustment on any nut.

1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.