Left Final Drive Lock-up

[Floater]

I've been working on this issue for a couple of days, and it's time to ask for some help from you guys.

1956 Cub restoration. I'm assembling the rear end after cleaning/rebuilding/painting. New gaskets, seals and some bearings.

The RH final drive is mated to the transmission and is working well. The issue is the LH final drive. When mating it to the transmission, when the final is fully seated it's totally bound-up, meaning the left axle doesn't rotate. If I back the final out a 1/4", it rotates normally when I rotate the clutch shaft. Push it back against the transmission flange again - locked-up.

I've disassembled the final drive to look for any issue. I removed the brake band, brake hub, and differential shaft. Everything looks fine; there's really not much to it. To me, it's acting almost like the differential shaft is too long. The snap ring on the differential shaft bearing is there. As for the differential itself, I never took it apart, just cleaned it and made sure the differential bearing shims were replaced correctly.

I'm looking for ideas or things to check at this point. Thanks for any help!

[Glen]

Hi,
Be sure the 2 ends of the brake band pin are in their holes before tightening the 6 bolts holding the final drive on the Cub.
It can break the castings to tighten the bolts with the pin not in both holes.

Final drives sometimes don't turn easily by hand because of the brake lining dragging on the brake drum.
Try bolting the final drive on fully, and put in 2 wheel bolts in the wheel hub, turn them part way into the threads, so they are sticking out some, use a foot long pry bar and pry between the 2 bolts, and see if the hub turns.
Try turning the hub both directions.

[Floater]

Thanks for the info Glen.

I tried the "pry bar on two lug nut" technique. I was able to move the axle only a very little with a lot of torque before it locked-up again. Something isn't right.

Following your idea about a tight brake band, I totally removed the brake band and re-installed the left final. Success - it rotates easily just by turning the clutch shaft. So the brake band is the issue.

These are new brake bands I purchased a few months ago from TM Tractor, and like this recent thread (viewtopic.php?f=1&t=113675) the rivets are sticking out the back of the brake band and catching on the housing. I guess they're putting a lot of pressure on the brake drum via a super-tight band. I need to re-rivet these new $40+ bands. Great. Here's a photo with the new band on the left, old band on the right.

[Gary Dotson]

I would try to support the rivets, from below and see if you flatten them down with a hammer. Those are for sure sticking up further than normal and another member recently had the same issue with them. He ground his down, to make clearance but I would prefer to flatten them, with a hammer, if you can.

[Bob McCarty]

As Gary suggested, find a punch that fits the countersink. Put it in a vise, place the head of the rivet over it and see if you can flatten the rolled end with a hammer.

[Glen]

Hi,
You should tell TM Tractor the band doesn't fit right, and the rivets are the problem.
They need more riveting so they are about like the ones the original band has in your pic.

They could buy riveting tools and rivet the new bands they have down more before selling them, if they have more like you bought.
I don't know if they would, but if they can't find any that are made right, it would be something they could do.

[ScottyD'sdad]

Hi,
You should tell TM Tractor the band doesn't fit right, and the rivets are the problem.
They need more riveting so they are about like the ones the original band has in your pic.

They could buy riveting tools and rivet the new bands they have down more before selling them, if they have more like you bought.
I don't know if they would, but if they can't find any that are made right, it would be something they could do.

I emailed Ron at TM, with the picture above, explaining the issues with the new brakes.

Ed

[ScottyD'sdad]

Response from TM

Thanks Ed

There are no quality brakes on the market. I have tried all of them. Even the ones from case are no good and they are crazy money. Im not sure the issue is with the rivets but more with how the brake is formed. We have some troubles with the rod style ones to. I wish someone would make something that would fit right for a change. Thanks

Ron


So, looks like we need to stop the Fred Flintstone way
Ed

[Eugene]

I emailed TM, with the picture above, explaining the issues with the new brakes.

I emailed TM about their Stock# FL522, IH or Zenith carburetor choke lever not fitting. Wouldn't clamp down on the choke rod. No response.

[ScottyD'sdad]

I've known Ron a long time, long before he bought TM. Maybe that helps.

Ed

[Don McCombs]

I emailed TM, with the picture above, explaining the issues with the new brakes.

I emailed TM about their Stock# FL522, IH or Zenith carburetor choke lever not fitting. Wouldn't clamp down on the choke rod. No response.

It may be that the splines on your choke shaft are worn. Or maybe the lever is not well designed or manufactured, or both. In any event, ignoring customer concerns is not good business.

[Floater]

Thanks for the ideas on flattening the rivets. For once in my life, I actually have the right tool - a "rivet anvil" which clamps in a vice and is used to install brake lining rivets. I've tried flattening the double-headed rivets on the new brake band with the anvil, and - they don't really flatten much at all.

I'm probably going to replace the rivets with some conventional brass brake lining rivets - once I figure out the size I need. McMaster-Carr offers them, but I don't really need 100, only 20 or so.

[Gary Dotson]

Ask Bob McCarty where he gets his rivets, when he relines brake bands. Probably McMaster and the large quantity was acceptable to him, since he planned to do several. I often find it’s less expensive, buying the larger quantity, even though I don’t need them.

[Bob McCarty]

PM sent.