No Going Backwards

[Steve Harrold]

I recently took my Model A on a trial in Wales. We blew a rear tyre, and found that a couple of wheel studs were loose.




Managed to change the wheel and tightened the nuts, and they didn't seem to be fouling the brake mechanism.
The odd thing we found later was that although the car travelled fowards without a problem, sometimes when reversing it locks up solid after a few yards. We got on axle stands and removed both drums, and it doen't seem to be the brakes.
We began to wonder if maybe the diff has a broken tooth, which is jamming it, but it seems odd that this should only happen in reverse.
Obviously I need to get it up in the air and work through it all, but would appreciate any wisdom to guide me to the likely cause.

[Bob C]

Drain the lube in the rear axle and look for metal.


Bob

[2manycars]

Look carefully at the inside of the brake drums. One of your wheel studs may not be seated fully, and is protruding into the brake mechanism, catching the parking brake actuator when reversing.

[Patrick L.]

I agree with Bill. Start with the parking brake assembly. Trying it while its together and on the stands may indicate which wheel has the problem. If its not that then you may have to remove the transmitter top and give the a reverse idler a look. But, I think you'll find the problem with the park brake.

[Steve Harrold]

Thanks for your replies, will investigate the parking brake assembly, and also see what comes out of the diff. Steve

[Steve Harrold]

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Thanks for all of your help. I've now dismantled both rear hubs, and find that on one side I've managed to screw in the hub so far that the back of the studs was binding on a brake pivot pin. I didn't think that it should be possible to do this with a socket and bar - does it suggest that something is missing to enable it to go too far on, or am I stronger than I look?

[Patrick L.]

The hub/axle nut should be tightened to 100-125#. You may need to add an axle shim or two.

[Tom Wesenberg]

That C shaped connecting link appears to be stamped steel, which I'd think is aftermarket. All the originals I've seen appear to be forged. Also I see a wavy washer under the head of the toggle pin. I've never seen that on originals. I'd move the wavy washer to the back side and see if that helps.

[larrys40]

Steve
As Tom had noted but it also appears that he one connecting link on the forward side is flipped from what is should be. That can cause the brake to stick and the e brake to not fully retract.

I’m surprised you don’t have a problem going forward but it could be the lining is catching when rotated going in reverse causing the brake to actuate.
Either way the issues tom and I indicated need to be fixed. You can always remove the e brake at the c actuator in both sides or one and then other to prove your problem.
Larry Shepard

[Steve Harrold]

Originally Posted by Patrick L.

The hub/axle nut should be tightened to 100-125#. You may need to add an axle shim or two.

Thanks, have ordered some shims.

The Torque setting used last Saturday was my arm strength in a dark wet Welsh field!

Note improvised use of a Manitou fork truck as a handy jack!

[Steve Harrold]

Originally Posted by Tom Wesenberg

That C shaped connecting link appears to be stamped steel, which I'd think is aftermarket. All the originals I've seen appear to be forged. Also I see a wavy washer under the head of the toggle pin. I've never seen that on originals. I'd move the wavy washer to the back side and see if that helps.

Thanks Tom, I must say your hub looks much smarter than mine. I don't know much about the provenance of the car, but it quite likely has a number of aftermarket parts on it. I'll move the washer when reassembling.


Since I discovered that the studs weren't really swaged in at all, but had a bit of braze on the back to secure them, I begin to question the expertise that's been lavished on it?

[Patrick L.]

Well, from the above info maybe the shims are not needed once things are set right.

[katy]

You may need to add an axle shim or two

FWIW, one thick shim is a much better choice than 2 thin ones.