F Cub - Dropped ball bearing in gearbox while cleaning

[ptss88]

My grandfather's 1950-something F Cub got stuck in reverse the other day, and, when I opened up the gearbox to take a look, there was evidence of water intrusion and mixing with the gear oil.

I drained it, cleaned it, added fluid and detergents to remove any gunk, and drove it around a little, but it wouldn't pop into reverse or first properly. It would engage, but not lock into gear, and would just fall into neutral.

I opened it up and drained it again today, and believe I traced the problem to a steel ball bearing that sits on a coil spring in a channel cast into the gearbox housing. It's a little ball that pops into each of the three notches on a sliding pin as the gear carrier for first and reverse goes to each of its three positions.

I was using an air gun to blow out some gunk before I even knew about the ball, and discovered it just as it dropped down between the gears and into the bottom of the gearbox.

At the time, the drain plug was open, and the tractor was on relatively level ground, with the drain over a collecting funnel and jug.

I've tried and failed to get a visual of the ball, to hear it moving by probing with a curved steel rod, to suck it up with a garden hose attached to a shop vacuum, and to blow it so I could see or hear it.

Is the ball bearing most likely sitting out of sight in some recess of the case, below the gears, or could it have rolled through some type of channel into the differential, or out the drain?

I don't have experience rebuilding gearboxes, and have not split a cub open yet, so, any suggestions as to the most likely location of a ball dropped into the gearbox and the easiest way to retrieve it would be much appreciated.

[ptss88]

As this is my first time posting on this forum, and my first time using PHP in a long time, I'm not that spry when it comes to formatting and attaching images.

Please bear with me as I attempt to resubmit linked images showing the model number of the cub in question and the gearbox, with the channel from which the ball bearing escaped circled in blue.

https://drive.google.com/file/d/1LagAud ... p=drivesdk

https://drive.google.com/file/d/1LahyBs ... p=drivesdk

[Eugene]

Small magnet on a telescoping handle.

If you have a mechanics mirror on a telescoping handle, try to locate the ball first.

[indy61]

I lost one myself and could never find it, don't know if it dropped down in the tran or what.

http://www.tmtractor.com/new/tr/1953fp.htm

http://www.tmtractor.com/new/tr/2768fp.htm

[ptss88]

I was thinking that I'd need to pick up on of those magnetic probes. The mirror is a good idea, too. Thanks for the tip, Eugene.

I tried using a strong magnet from outside the case to get the ball to roll, but had no luck. I'm guessing that I just magnetized the whole case instead of twitching the ball, because of all the iron in between.

The ball itself should be regular steel and I should be able to retrieve it with a magent, right?

Also, I only saw one ball fall, but I'm now concerned that there may have been more than one. Can anyone confirm that there is only one ball per spring?

[ptss88]

Thanks for the product links, indy61. I suspect that the spring may still be serviceable, but if I have to order a new poppet ball, as I now know it is called, I may as well get a spring, in case the old one had some issue.

I'm just really nervous about refilling the fluid and running the gears with some unknown menace rolling around inside the case.

Thanks for the swift replies, guys. I've been lurking on these forums off and on for a few years, but this is the first time I've had a problem like this.

[Barnyard]

Did you look for the ball in the drain pan?

[ptss88]

Hey Barnyard,

I'm not even sure what route the fluid takes while draining. Where would you describe the drain pan, in relation to those gears? Is there a channel underneath, or is there a hole that leads to the rear diff? I don't know if the drain plug drains from the diff, or directly from the gear box. The internal layout is new to me.

[Jim Becker]

I lost one myself and could never find it, don't know if it dropped down in the tran or what.

Me too. I'm sure mine is still in there somewhere.

[indy61]

There is no drain pan on the trans and no way it could get to the engine drain pan.

[ptss88]

I didn't think the engine drain pan was a possibility, because it would have to get past two or three bearings and seals to get there. I was hoping that there was maybe some kind of accessible collection area when I read those words, though.

[ptss88]

I'll pick up a magnetic probe and mirror tomorrow, and see where that takes me. I'll also strain the drained fluid to see if the ball fell down the funnel.

I've already been planning on having to split the cub to do the rear main seal (FAST oil leak), and I'd hate to have to disassemble the rear end just because I goofed and literally dropped the ball.

[Barnyard]

There is no drain pan on the trans and no way it could get to the engine drain pan.

I'm talking about the pan or jug or what ever he drained the old oil into.

[Glen]

Hi,
It looks like your Cub is a 1952, if the serial number plate in your pic is original, and using the info at the top of the page.

There is one ball on each of the shift rods.

Below are pics from TM Tractor of the transmission housing.

The oil drain plug is about under the center of the trans, I think it drains the oil from the differential side of the housing.
The housing has an opening between the trans and differential to let oil through.
I don't know if you found the drain plug, or removed it.

I think Barnyard meant was the ball in the oil drain pan, if you put a pan under the drain on the trans, when draining the oil.

The ball cannot get to the engine oil pan through the tractor.

Below are pics, the oil drain plug is visible in the 1st pic, at the bottom of the trans.
The 2nd pic shows the inside of the housing from the rear, with most of the parts removed.
You could remove the PTO, if the Cub has one, and the rear cover, and look for the ball. You could clean more with the rear cover off also.
The 3rd pic shows where the trans oil level plug is, it is low on the left side of the trans. Fill the trans only to there. It holds 3 1/2 Pints of oil.

I would clean the hole at each end of the oil trough, in the front part of the trans, the oil is supposed to run down to the bearings through the holes.
I use a small drill bit, by hand, no electric drill, and turn it down into the holes, that collects the dirt on the bit. The bit may not go all the way in in one try.
You may need to pull the bit out, and clean it and turn it in again to go deeper.
After cleaning the holes as much as the bit will do, you could use compressed air to see if the holes are open into the bearings. Wear your safety goggles when using the air.

[Dale Finch]

Probably the easiest way to get it out is if you have drained the transmission, use your new extension magnet into the drain hole and fish around. If that doesn't work, and you really want to get the ball and spring out, you can remove the PTO, which opens up the whole rear of the differential, which should give you more room to fish around.

At the very least, I would suggest you put the tractor into neutral (if you can), engage the PTO, and spin it to make sure those two parts aren't wedged between any gears.