Before re-installing my motor what should I do to the tranny

Anyone know what this is called and how I should service it before re-installing the engine.

I know that's the transmission housing or "torque box", but what is the assembly that sits on the gear? How do I replace it? Is there a bearing behind it that I should service too?

What you're looking at in the picture is the bell housing. The transmission is the next one back.

What sitting on what gear? There's no gear in the bell housing. All I see is a red ring in the blur. Almost looks like it was heated up cherry red with a torch. Hopefully that's a reflection, and not cherry red hot. I can only guess that is either the front seal to the transmission, or the throwout bearing. Does it move forward and back when you press the clutch?

What should you service? Everything. Nothing. Just what's broken. Take your choice. There's no one thing that goes bad on a 60 year old tractor. It's all eligible to fail at any moment. If you want to be 100% sure, you can tear it all down, flush, clean, replace all seals and bearings. That'll take a long time and be very expensive. Or, if you know of something SPECIFIC that's shot you can fix that. Or, you can just slide it back together and drive it, then fix whatever breaks, when it breaks, down the road.

As long as you have it apart you should do the following. First thing I would do is clean the inside of the bell housing. Second, if clutch disk and pressure plate need replacing, do it now. You should also install a new throw out bearing. That's the thing that looks like it is cherry red in the pic. Check the transmission input shaft seal. If it is leaking, replace it. Put a thin film of grease on the tube the throw out bearing retainer rides on. After it is all together, grease the throw out bearing. There should be a grease fitting on the bearing carrier. While reassembling, be sure to inspect, fix and lube all the clutch linkage.

Any time you split any tractor I would replace the clutch, pressure plate, throw out bearing, tranny input seal and IPTO shaft if equiped unless you know for certain that those items are good. Clutch failures are the most common failure requiring a trator split so renewing those is a no-brainer. Plus any needed repairs needed that are easyer to do while the tractor is tore down makes sense too. I helped a friend do a clutch on his 986 this winter. While the sheet tin was off we also replaced the rear main engine seal, IPTO shaft and seals (tranny too), hydraulic oil cooler lines, a power steering line, fan belt and heater hoses plus anything else we could while things were easy to get at.

Rick

Hard to tell what we're looking at, due to the blurriness.

Here's my SA's bell housing on the torque tube, straight-on..



The round thing is the throw-out bearing. It sits on a Y-shaped yoke, which pivots at the top and the bottom. The top pivot is fixed, on a shaft that is inserted from outside the torque-tube. the bottom pivot is connected to the shaft that is pushed when you depress the clutch pedal- the bottom of the yoke moves forward, pushing the bearing onto the fingers of the pressure plate that is bolted to the back of the flywheel. This bearing is a relatively cheap piece, and I agree with the others that for all the trouble of splitting the tractor, replace it now, or risk having to re-split the tractor.
The shaft extending through the bearing, which does NOT move forward and back with the bearing, is the drive shaft coming from the tranny, (actually it c[u:3b601c18b3]ouple[/u:3b601c18b3]s to the tranny drive shaft, but to all purposes, it's the same thing).
There is no bearing or seal to worry about behind the throw-out bearing, because this shaft is a long one that extends all the way to the tranny, and you cannot reach through from the front. All you change here is the movable throw-out bearing.

Here's another pic from a different angle. The 'gear' you see is on the end of the tranny drive-shaft, and this gear extends into the clutch disc. When the clutch disc is 'grabbed' between the pressure plate and the flywheel, the clutch disc 'drives' this tranny shaft, imparting power to the tranny.



And with the better view, you can see that the bearing actually sits on a 'sleeve' that slides forward and backward relative to the tranny shaft. It is this sleeve that is actually attached to the yoke.

And a quick clutch explanation...

This is how the rear of the flywheel looks- it has the pressure plate assembly bolted to it with 6 bolts around it's perimeter...



You can see three 'fingers'- it is upon these fingers that the throwout-bearing pushes, when the clutch pedal is depressed. Beneath the fingers, through the center hole of the pressure plate, you can see the clutch disc. The splines of the tranny shaft slide into the splines in the clutch disc. Thus, the clutch disc, spinning with the flywheel, 'drives' the tranny shaft.

Here's the clutch disc by itself. You can see the friction material riveted to this disc, and the splines in the middle...



Here's a picture of the flywheel without the pressure plate assembly.



Here's the part of the pressure plate that faces inward.
With the clutch pedal OUT, this pressure plate, under strong spring pressure, traps the clutch disc between the pressure plate and the central surface of the flywheel. This action ENTRAPS the clutch disc, so that when the flywheel rotates, the clutch disc must also rotate, which powers the tranny.



The fingers pivot near their center. When the throw-out bearing pushes the inner part of the fingers toward the flywheel, the outer part of the fingers pull the pressure plate AWAY from the clutch disc. This allows the clutch disc to remain STILL, while the flywheel and pressure plate continue to spin. With the clutch disc NOT ROTATING, you are now able to shift. WHen you release the clutch pedal, and the throw-out bearing retreats off the fingers, the pressure plate again squeezes the clutch disc against the flywheel, and the tranny is under power.

It is this clutch disc that can wear out, and which thus causes CLUTCH SLIPPAGE. Or, these get coated with oil, also contributing to slippage. Or, the pressure plate gets [u:99b5f60e6a]warped[/u:99b5f60e6a]. This was the case with my pressure plate above- you can see that it was grabbing in only 3 spots, and not over it's entire circumference.

Again, for the relative cheapness of these parts, I join the others in recommending that you consider the health of the clutch disc, and the condition and surface of the pressure plate, and the surface of the flywheel. My picture above, of my flywheel, shows how it was resurfaced so that it was absolutely flat.

One last thing- in the rear of the crankshaft, internally, is a small bearing/bushing. The tranny shaft, that goes through the middle of the throw-out bearing and the pressure plate and the flywheel, comes to rest within this bearing/bushing. This is what keeps the tranny shaft runnig straight and true, or it would be flopping around as it spins. Definitely consider replacing this piece in the crankshaft.

Okay, I'm picking up what you guys are putting down. I will order this tomorrow.

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Oldtanker, I do not have a clear understanding of what a "tranny input seal or an IPTO shaft" is, but I would definitely like to replace those.

I do not want to ever have to split the tractor again.

Thanks guys. This guys. This is what it's all about. Passing on the Farmall knowledge, keeping classic American Iron alive.

IPTO is independant PTO (live plus dirves the hydraulics on newer tractors) which you don't have, my mistake. The tranny input shaft you do have. That's the splined shaft that is in your photo. It has a seal on it where it goes into the tranny. While it's apart I would replace that too.

Splitting a tractor isn't the best job in the world and unless you enjoy splitting one I'd fix everything in there I could afford to. I'd also repair and replace anything that needed attention while the sheet tin is off too. Just make it easyer to work on.

Rick

IPTO is independant PTO (live plus dirves the hydraulics on newer tractors) which you don't have, my mistake. The tranny input shaft you do have. That's the splined shaft that is in your photo. It has a seal on it where it goes into the tranny. While it's apart I would replace that too.

Splitting a tractor isn't the best job in the world and unless you enjoy splitting one I'd fix everything in there I could afford to. I'd also repair and replace anything that needed attention while the sheet tin is off too. Just make it easyer to work on.

Rick

If you are going to replace the input seal on the tranny i would also replace the bearing as it sits just behind the seal.