Final Drive Question

[lyle11]

I have a 1948 Cub that has had very poor brakes for a couple of years that I have been putting off fixing. I could hear a constant noise in the right final that sounded like the brake was moving around. I finally took it apart and discovered that the brake band anchor pin was missing. I installed new brakes about 15 years ago.

I read in another thread that the anchor pin is 5/16”. I put the shank end of a 5/16” drill bin in the hole and there is some wallowing of the hole. It doesn’t appear so bad that the pin would pop out but I don’t have any experience with what is acceptable.

I don’t have the skills to drill out the hole and install a bushing. I don’t want to put it back together only to have it fail again. I don’t recall the condition of the pin I installed 15 years ago but it was used.

I also inserted the 5/16” drill shank in the hole on the other side of the final (used if the final casting was installed on the left side) and the drill bit fits tighter but the fit is certainly not tight.

My least expensive approach is to buy a new pin from TM and put everything back together. My questions are:

1 - Based in the photos does the hole appear excessively worn to the point of needing repair or a replacement casting?
2 - I see the Brake Band Spacer in the drawing and mentioned in a past post but TM doesn’t sell it. I have no idea if I installed this spacer 15 years ago. I can’t even tell what it’s function is without seeing one. Could a missing spacer cause the pin to fail or fall out?

Thanks

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[Glen]

Hi,
I don't know how the pin could fall out when it is in place, it fits in a hole at each end.

I can't quite see in your pics, it looks like a chunk of the casting at the hole may be broken out.
The casting shape should look the same as the unused hole, if it was never used.

The holes can get broken when putting the final drive on the Cub if either end of the pin is not in the holes, and you tighten the 6 bolts holding the final drive on.
There have been other people on here with pics of broken holes.

The final drive should slide fully into position on the top and bottom dowel pins without using the bolts to pull it into place.
Watch closely when putting the final drive in place that the pin is in place at both ends.
Be sure you have the top and bottom dowel pins at the mounting in place, they should be tight in the right side extension, and the final drive slide on them.

While the final drive is off is a good time to replace the 2 oil seals on the upper shaft, if you didn't.
If they leak oil, it will probably get on the brake.
To replace the seal in the transmission, you have to remove the seat post, battery box, and loosen the platform, so the rear of it will lift up, then remove the right side extension.

You can look in the extension with a light and see if the seal is leaking.

A 1948 Cub should have the 1st style of brakes.
Below are pages from the Cub parts manual.
The 1st page shows the 1st style of brakes in the upper pics.
If you mean the spacer number 7 in the pic, it is a separate spacer.
The 2nd page shows it was used only on Cubs serial number 18558 and below.

http://www.farmallcub.info/manuals/cub_ ... 004-02.jpg

http://www.farmallcub.info/manuals/cub_ ... 004-03.jpg

If you bought a new pin with the spacer made on it, that pin should work.

Pics with more light would be helpful.
If the casting is broken where the pin goes, the pin may not stay in place at that hole, I don't know for sure.
When you apply the brake, it pulls the pin toward the side of the hole that is ahead.

Below is a pic from TM Tractor of a final drive, showing the holes for the pin.
The 2nd pic shows putting the pin in the hole while putting the final drive in place. It is the newer style brake, but the same idea.

[tnestell]

Could someone just swap left to right, right to left?

[Clemsonfor]

Yea the finals will swap side to side.

[lyle11]

Thanks for your replies.

Regarding any breakage around the hole, pictures aren’t the best, but there is no breakage or even an egg shaped wear around the hole. It’s just bigger all around than 5/16”. I have no idea how a pin that is locked in place between 2 castings could fall out. But it was gone.

Regarding swapping of the finals left to right. Obviously the long shaft and short shaft that mate with the transmission would have to be swapped. If swapping castings side to side doesn’t involve needing a press or tools I don’t have then that’s probably the way to go.

If anybody is aware of what would need to be done swapping finals side to side please let me know if there is anything other than the long and short shafts. I haven’t searched for a thread regarding swapping them yet so it’s possible this has been covered already.

Also, I’m still wondering about the Brake Band Spacer (part # 56 151 D).

Thanks

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

If it were mine, and I have owned cubs and been repairing other peoples cubs for around 35 years I would just put it together as is. That pin does not rotate, it only anchors the end of the brake band. Once the final is bolted in The pin is in a blind hole at each end and cannot fall out. If you are considering swapping sides with the finals, the top shaft has to be switched, plus if you intend to use any planter attachments the drive on the axle also has to be switched.

[Don McCombs]

I’m with John. Replace the pin and drive on.

[Glen]

Hi,
If the hole for the pin is not broken, it should work to just put it together with the final drives on the sides that they are.
The spacer was used only on the first Cubs, up to serial number 18558, it is just a different style of pin than the newer pin.
You didn't say what your Cub's serial number is.
The newer pin has the spacer made on it.
Below is a listing at TM Tractor for a new pin, it should work in place of the old pin and the separate spacer. Read their description of the serial numbers that it fits.
You don't need the separate spacer, using the new pin.

http://www.tmtractor.com/new/br/518fp.htm

[lyle11]

Glen, thanks for the clearing up my spacer question. My Cub SN is 48XXX so I don’t need it.

I’m going to order a new pin from TM and put it back together.

Thanks to all for for your comments and suggestions.