Bought this tractor a couple months ago. Noticed it had a rear main seal leak, along with several others. After I got the front axle rebuilt and back under it I decided I'd tackle the rear main seal. I built a stand on wheels to fasten to the front half of the tractor. Already had the rear half on a fixed stand. After 4 hours of unhooking everything I got it apart. I hung 2 weights on the front to take some weight off the stand. Now realize that was unnecessary.
The rear main seal had obviously been leaking a long time. The clutch was totally oil soaked and one spring in the clutch disc was broken. So project changed from seal replacement to clutch replacement.
Getting the tractor apart wasn't really difficult. As I said, it took me about 4 hours. My 43 yr old mechanic Son would have done it in an hour. These tractors are designed and intended to be used for a very long time. They are built to take apart. Also being a 30 year old tractor it's not limited by cosmetics and current technology. Wiring is pretty straight forward as is the fuel system. All oil systems affected were easy to separate. And only had to remove one piece of sheetmetal, the hood.
If you've never saw a Ford clutch system on a tractor with "independent" PTO, look closely at the closeup lighted picture of the clutch assembly before I removed it. You can see the disc splines, back in the center hole. Then if you look closely you can see another larger splined hole that is part of the pressure plate. When the engine is started the pressure plate turns with the flywheel, regardless of what position you have the clutch pedal in. This provides constant and unbroken rotation of that larger splined hole. The smaller splined hole in the clutch disc only turns when the clutch is engaged. Push the clutch pedal and the disc stops turning. This provides the ability to stop/start the tractor's motion.
If you look at the picture showing the transmission housing you can see the PTO gear box on the front of the transmission. You can also see a splined, hollow shaft that fits the larger splined hole in the pressure plate. Coming out of that hollow shaft is the smaller splined shaft that is the transmission main shaft. So, engine running, clutch engaged, both splined shafts will be turned at engine speed. Disengage the clutch and the smaller, transmission shaft stops turning which stops tractor movement. Meanwhile the larger hollow shaft continues to turn which provides uninterrupted service to the PTO oil clutch located in the rear end housing. Thus "Independent PTO". Confused yet.
After removing the pressure plate/clutch disc from the flywheel I removed the flywheel and the shield that covers the rear main seal. Removed old seal, installed new seal. Both very easy tasks. Then took the flywheel to a machine shop and had it "turned". This resurfaced the flywheel getting rid of the oil saturated surface as well as removing any distortion. Makes for a very smooth new clutch operation.
While apart I also replaced the pilot bearing. sorry I didn't get a picture of that. It's a small bearing that goes into the end of the crankshaft. The pilot shaft on the end of the transmission shaft goes into the center of the bearing. It's purpose is to hold the transmission shaft in line with the engine crankshaft so there's no shaft wobble and/or clutch disc wobble under load.
Then I installed the new clutch assembly and was ready to put the tractor back together.
Sorry, I forgot to mention. In regards to installing the clutch disc and pressure plate to the flywheel. The tool of choice is a pilot shaft. They are often made of plastic with the proper sized end to fit the pilot bearing in the flywheel and the correct splines to fit the clutch disc. Purpose being to hold the disc in the proper alignment while you tighten the pressure plate. I did not have one. So I used the tried and true shade tree mechanic method. I started the bolts thru the pressure plate into the flywheel. While they were loose enough that I could move the disc by tapping it, I centered it on the face of the pressure plate. Feeling all around the edge of the pressure plate and ensuring the disc was centered, I tightened the bolts. I've used this method several times with success.
Sorry I didn't get many pics of putting the tractor back together. But it was very uneventful. My wheeled stand on the front half worked great. When I had the two pieces close enough together I put a C clamp on each side and gently used them to help me pull it all together.
Understand you have a lot going on when putting it back together. The pilot shaft end of the transmission shaft has to go into the pilot bearing. The splines on the transmission shaft have to mesh with the splines in the clutch disc. The splines on the pressure plate for the PTO have to mesh with the splines on the PTO shaft coming out of the transmission. The dowels, one on each side of the transmission housing have to hit the dowel holes in the engine block.
With that said, DO NOT use excessive force pulling it all together. Damage can be done to the clutch assembly or transmission shafts, or pilot bearing. I snugged up the C clamps and then wiggled the front half of the tractor as well as turning the flywheel with a screwdriver. Tightening a lit at a time as it slid together. Piece of cake.....
Also, forgot to mention, I replaced the "throwout bearing". This bearing allows the clutch to be disengaged by pushing on the fingers of the rotating pressure plate. Always, always replace all wearable parts when doing a clutch replacement. Not worth trying to save a few bucks when the labor is so intensive to get there.
I bought the rear main seal thru CNH, I believe it was around $50. I bought the clutch, pressure plate, throwout bearing, pilot bearing thru the local CARQUEST Auto Parts store. Cost for those parts were $375. And that was new parts, not a rebuilt clutch/pressure plate.
Took me 3 hours to put it back together. So total of around 7 hours. Being FWD added some work because you have to remove the driveshaft for the front axle. Again, someone that spends more time working than thinking about what to do next could easily cut that time in half.
Thanks for your post. My 3910 has a worn clutch. The New Holland place wants $800 labor and $500 parts.
How did Carquest find the parts? I cant find any tractor parts in the online store.
I enjoyed your post as I will be replacing my clutch on my Ford Gas 3000 next week. Think I will build a stand like yours to support the tractor. Nice pictures. I have not fooled with a clutch in over 40 years, and that was a 67 GTO. I am a little scared but sure I will get over it.
