L3710 GST Clutch failure

[dsdillner]

I could not find a discussion on this so I'll start a thread to ask my questions. I'm sure there are a lot of experts here who have good suggestions.

A little background, a couple of years ago I left the tractor out more than usual (usually in my garage) and the clutch disk stuck to the flywheel. I limped along using the hyd clutch and eventually the disk popped loose and I continued to use as normal but the clutch pedal needed to be depressed all the way to disengage the clutch. So I attempted to adjusts but the turnbuckle was maxed out as short as I could make it. Then last summer the clutch got worse and I could only get partial disengagement. Put it up for the winter and tackled it this spring. I have the tractor split and have a new clutch kit. When I took it apart I noticed the clips that hold the throughout bearing were in the bottom of the housing. I thought the new kit would come with the clips but it did not. The clutch pressure plate and disk do not look bad to me but I will replace.

I suspect the failure occurred because the clips were not holding. I have never seen such a weak design using these little wire clips to hold the fork to the bearing carrier. I am tempted to add some SS wire. Has anyone done anything to make this a bit more robust. It's a real PIA to split the tractor. Any advice here would be appreciated. Thanks Dan

 

[lugbolt]

if you pull the clutch pedal upward (towards you) when the its stuck, those clips will usually fall right off. Done many like that, not unusual. Yes put a new disk in-the originals often lose the splines. Oh and block the pedal down when you're not using the tractor.

 

[dsdillner]

if you pull the clutch pedal upward (towards you) when the its stuck, those clips will usually fall right off. Done many like that, not unusual. Yes put a new disk in-the originals often lose the splines. Oh and block the pedal down when you're not using the tractor.

Thanks, I did learn about locking the pedal but after the fact (horse was out of the barn!!). I'm thinking there must be a better way to hold the fork to the bearing carrier. I have new clips on order but there must be a way to add safety wire or something.

 

[lugbolt]

on automotive applications they use a fork, and it's usually loaded a little bit. Kubota uses a similar design but not quite the same-the clips keep the fork in contact with the release bearing. They aren't 100% necessary but helps keep the pedal from flopping around since it's not spring loaded. Some older Kubotas had a spring on the pedal that kept some pressure on the pedal linkage.

 

[North Idaho Wolfman]

The main reason for those clips is to pull the throwout bearing away from the Pressure plate fingers, they really don't ever get any force put on them.
Them not being on there didn't do anything to cause it to clutch issues.
Put a new Pilot bearing/ bushing it it, and a new throwout bearing in it while your in there.

One BIG note: DO NOT surface grind the flywheel, Kubota's do not like you doing that.
The best thing you can do to the flywheel is just put a light sand on the surface.

 

[dsdillner]

I think I figured out why the clutch operation failed. The clips serve two purposes and as pointed out should not have significant pressure on them. They pull the bearing carrier back away from the pressure plate and they keep the bearing carrier lined up so the forks contact the carrier at the contact point. Without the clips there is nothing to keep the carrier from rotating and giving the forks nothing to push on. In my case the clips were in the bottom of the bell housing and were expanded. The bearing carrier did not slide smoothly for and aft with the forks, maybe putting more pressure on the clips than designed for. A very weak design IMHO.

I am back together now or almost with new pressure plate and throughout bearing which were not needed but since I have it parted and have a new one This model does not have a pilot bearing as you can see looking at the blunt splined shaft. I cleaned the flywheel and lightly sanded. I'll have it back in service hopefully this evening.

Thanks to all who responded