New member-rear drive disassembly questions

[49willard]

I am a new member to the forum but have owned and used my cub since 1976-a great machine. It has plowed my driveway in northern New England essentially every snowstorm for 43 years.

I am leaking gear oil from the transmission/rear drive out thru the right side axle tube. It comes out of the weep hole in the bottom of the final drive casting below the brake band area. I am confident that it is coming from the transmission/rear drive and not from the final drive since I can't keep gear oil in the transmission. I have seen posts on the subject but not a step by step procedure to replace the differential shaft inner bearing seal , part # 385872R91 which I believe is the source of my leakage. For example, can't the entire final drive, axle tube and axle be removed as one piece? Or is the problem on reassembly getting the assembly lined up such that the axle spline goes thru the seal, inner roller bearing and aligned to the differential drive gear that slips onto the spline?
Thanks in advance for any suggestions.

[Dale Finch]

This is a post covering the LEFT final removal, and the right side is similar, as far as the setup goes.
http://farmallcub.com/phpBB2/viewtopic.php?f=142&t=78436

The right is, however, a bit more complicated, since access to the differential seal requires removal of the axle extension, and that is attached to the platform. Platform removal involves removing the seat post and the battery box...and those tasks can be daunting if they have the usual corrosion from the battery.

Here is a post I did for the Super A, and it is quite similar...maybe this will help:
http://farmallcub.com/phpBB2/viewtopic.php?f=170&t=64496&hilit=SA+final+rebuild

Since you wouldn't want to do this more than once, I would recommend that you also check the brakes, and replace the final seals as well. Good luck, and welcome!

[Dale Finch]

An important note: the transmission only holds 3 1/2 PINTS, and often gets water in either through rain/washing or condensation. If overfilled or level raised due to water, the differential seals most likely WILL leak. You might consider checking the fluid level before you do anything else. This is achieved by removing the small square-headed plug on the lower left side of the transmission, between the block and fender. When removed, any fluid that comes out is excess. If it looks like a chocolate milkshake, you might as well drain, flush, and refill the transmission (3 1/2 PINTS only). This could save you a lot of work, as that may be your only problem.

[49willard]

Dale,
Thank you for your responses. The links are very helpful. I am confident that the problem is not a case of overly full. It would be great if that was the case!
In summary it looks like the right side drive can be removed as one piece which I will do, however, it sounds like full breakdown is in order to replace both the inner and outer seals and check on the brakes at the same time. I think that I will do both sides, one at a time.

[Frozenstate]

Mine leaked like you are describing. Drained it out, way overfilled with water and gear oil. Lots of water! Got it flushed out and filled it to the fill level plug with oil and it never leaked again. It is easy to pull the fill level plug and check the level. Maybe try that first.

[John *.?-!.* cub owner]

I am with Dale and Frozenstate on this, before pulling the final, drain the transmission. The final holds very little oil, and it only gets anywhere near the upper seal by the bull gear picking up oil, and then oil being transferred to the upper gear, and any surplus getting splashed into the bearings, then finally getting to the seal.

[Glen]

Hi,
I would remove the right final drive from the right side extension, to remove the final drive from the Cub. Then the brake is visible.
It's best to replace all the oil seals on the upper shafts when you remove a final drive.
There is basically an oil seal on each side of the brake drums. 2 seals on the right side, and 2 seals on the left side.
TM Tractor, at the bottom of the page, has listings for them, the seals in the transmission housing are a different size than the seals in the final drives.

[49willard]

I should explain further why I believe the problem is the seals, the inners for sure. I had "restored" the front of the tractor about 30 years ago when I swapped an uncracked engine bare block for the one in the tractor which was cracked when I purchased it. The original engine needed to be rebuilt at that time which I did, with the new to me uncracked block. I never repainted the rear of the tractor and felt that it was due which is where I am at. There was lots of oil out toward the wheels, particularly the right side. I dropped down the 2 pans below the bull gears, both had plenty of oil. When I drained the transmission I did not get anywhere near the 3 1/2 pints of gear oil. I know that I had checked the transmission oil level in the past. The good news is that despite running low on transmission/diff oil there are no bad noises and it shifts just fine. They are tough tractors! I will verify that the inboard bearings are ok at the time I replace the seals and replace those bearings if needed. I will also check on the brakes at the same time.
Thanks again for your posts.

[Stanton]

Easiest way to check for an overfull tranny is to open up the level plug on the left side of it. If anything drains out, it's overfull.

By the way, welcome to the forum! What a great testimonial to the service these little Cubs. Forty-three years is quite a long time for any machine.

I'm assuming you have all the manuals you need, but in case your don't, now that you have more than 2 posts, you can access all the free PDF downloads in the Manuals section. They are located via "Quick Links" in the upper left corner of your screen. Hit that and a pull-down appears where you'll find "PDF Manuals". Through that link, you'll be able to download an Owner's Manual and any service manuals that interest you (that includes the service manual on the tranny). Implement Manuals are also available.

Take some time and read through a few threads to acquaint yourself with the Forum:

• Welcome Wagon
• How to Upload Pictures to a Post
• Forum Picture Posting And Other Interesting Things You Can Do
• Using the Forum

Take some pictures of your tractor and post them. We’d like to see it.

Glad you joined us.

[ntrenn]

450043 national cheapest and easiest at Oreilly.

Just did both sides on the 65 Loboy this summer. I did one side at a time. Just take off hunks at a time...wheel, battery, seat, floor pan, final, extension tube. Peel out the seal. Drive in the new one...then put it back together. 2-3 hours for the right side...about half that for left. Do them both while you are at it.

[49willard]

Successfully replaced the inner and outer drive seals, it appears that that fixed the leak. Thanks all for your responses. This is my cub:


Well I tried to enclose a picture of my cub. Is there a number of posts required or some other reason/way to post a picture?

[FIRSTCUB]

you don't mess around ! Glad you got it fixed !

[Dale Finch]

Click on FULL EDITOR & PREVIEW, then below the post window you should find a tab labeled ATTACHMENTS. Click on that, and you will see ADD FILES, where you should be able to find you photos and add them. They must be a small size, though.

[49willard]

Second try posting a picture of my cub, thanks Dale! Note that my wheel rims that I just repainted were originally red. I see a lot of Cubs with silver painted rims. Is there an explanation

[Dale Finch]

The rims were originally just galvanized steel. Many folks use "Aluminum" or a "Hammered" silver which are close to the original color/texture. I used a gloss silver, simply because it was easier to keep clean!

Nice looking cub!!