1990s Ford 3930 slow moving..

LondonDave · Feb 25, 2015

I've got it adjusted properly now. I had to turn the yoke out about 1/2" total and I've got the 1 1/4" free place before I start to feel the spring. I cranked it out even more and I was up to almost 3" of free play so I brought i back in. It seems to be working good now. I didn't run it for very long to see if I was still getting that smell...Didn't have time, have to get ready to go to work.

As for the part that goes into the diff I'll have to take a picture another time and show you.

Thanks for your help.

Dave

GManBart · Feb 25, 2015

ovrszd said:
Too much free travel makes it impossible to disengage the clutch. Pedal hits the floor before it disengages. Too little free travel holds the clutch in a partially disengaged position which can result in slip as he described.

Sorry, meant to say take-up rather than free travel.

ovrszd · Feb 25, 2015

I glanced at my 3910. I'll take a guess at what you mean. You looked at the shaft where the clutch pedal swivels. You moved the pedal and at a glance didn't see any movement? If this scenario is true the following explanation applies. If not, please ignore.

The shaft that the clutch pedal swivels on performs two duties. It runs completely thru the rear housing of the tractor exiting on the opposite side. On that opposite side the left brake pedal fastens to that shaft using a square key and a bolt tightening it to the shaft. So when you push the left brake pedal you turn that shaft. Now back to the clutch pedal side of the tractor. The first thing on that shaft as it leaves the housing is the clutch pedal. It "coasts" on that shaft allowing the clutch pedal to be moved without shaft movement. On the outer end of that shaft is the left brake lever. It is also keyed to the shaft and clamped with a bolt. To it is fastened a rod that goes rearward into the brake housing on the rear axle assembly. So, if you just glance at the end of that shaft and move the clutch pedal you will wonder why that assembly you see isn't moving?? It will not move until you depress the left brake pedal.

Hopefully this helps.

As to the clutch issue. Use the tractor as is. I would only replace the clutch if it will not hold a load such as pulling a heavy load or slipping when in high gear. Or if you continue to have that smell, which would indicate it is slipping all the time. I'm guessing it was only slipping because it was severely out of adjustment.

I pay very close attention to both, clutch and brake pedal "free travel". Set correctly you get the best result. Set incorrectly you are wearing out parts such as clutch disc or brake discs for no reason.

LondonDave · Feb 25, 2015

Yep that's what I'm talking about. There is also a rod that goes to the rear diff. It looks to me like that should move but it doesn't. I was just curious about what it did. Something to do with the PTO maybe (just guessing).

Thanks again for the help with the clutch. I'll keep an eye on it and make sure it stays properly adjusted.

Dave

ovrszd · Feb 25, 2015

Are you referring to the rod that's fastened to the cast arm on the end of the clutch pedal shaft under the floorboard?? This rod goes into the rear diff housing? That's the left brake rod.

Look at the attached picture. There are 3 arrows.

The red arrow is pointing at the clutch pedal assembly. My exhaust is in the way so you can't see the lower part of that assembly where the rod is fastened that runs forward where you adjusted earlier. This assembly coasts on the shaft which allows the clutch pedal to be moved with no impact on the position of the shaft.

The yellow arrow is pointing at the shaft that runs thru the tractor housing. If you look at the end of that shaft you can see the keyway that fastens the brake assembly to the shaft. This causes that assembly to move when the shaft rotates. This rotation is controlled and activated by pushing on the left brake pedal with your right foot.

The black arrow is pointing at the rod that goes rearward and into the rear diff housing. This rod activates the wet disc brake for the left wheel. When the brake pedal is pushed the shaft turns, which also turns the assembly on the shaft (yellow arrow), which also pulls on the rod (black arrow) to activate the brake.

Clear as mud right??