Did the Newbie Find Something Dangerous?

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Model T Ford Forum: Forum 2012: Did the Newbie Find Something Dangerous?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Coiro on Wednesday, September 05, 2012 - 02:54 am:

I took that newly varnished wheel you're sick and tired of hearing about and bolted it onto the rear axle. When I tried to spin the wheel, it was very hard to move and it made a grinding sound. I removed the wheel and found some freshly worn, shiny spots on the side edges of the parking brake shoes and on the inside of the parking brake drum where the shoes were rubbing. So, okay—I got a wrench and pulled the parking brake shoes out to file down the edges that were rubbing against the drum. When loosened the bolt and nut that holds in the brake shoes...



... I noticed that there was a cotter pin hole in the bolt (photo below).



But the nut that was on the bolt was neither a castle-type, nor a lock-nut. That didn't seem right, so I checked the other brake on the other side of the car. Yup, there was an ordinary, non-castle nut there, too (photo below).



Now I'm wondering whether I have a dangerous situation.

I'm planning to replace those two nuts with the castle-type, but I'm wondering whether some of the other nuts on these brakes should also be replaced. In the photo below, are these ordinary nuts okay, or should they be replaced with another type?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Wednesday, September 05, 2012 - 05:26 am:

Can't be sure from a photograph, but it appears that there are lock washers under most of those nuts. IF those are lock washers, in MOST of those locations, they are adequate. However, in one location, I would not consider a lock washer to be okay. That first bolt you are referring to on both sides, the one that holds the spring loaded flat bar that also helps the back half of the brake band to stay in line with the drum. With road vibration and the action of the brakes, that flat bar can move slightly. That can result in the lock washer and nut turning. It likely would tend to tighten the nut, which could restrict the bar from moving with the brakes as it should, but otherwise be okay. It could manage to work the nut loose and vibrate off. That also would not be terribly dangerous because the brake band is well attached at the front and would not allow the band sideways enough to allow the bar to fall out. The bar, held in still by the springs, would likely still prevent the band from moving sideways enough to allow the brake band to cut into the wood spokes.
The key word in that entire diatribe, is "likely". It could fall out. It could allow the band to cut into the spokes. And you could break a wheel when you least expect it and under dire circumstances and the results could be disastrous.
That bolt should definitely have a castle nut. It should be snug, but loose enough to allow motion in that bar to the band if it needs it. It should then be cotter pinned.
To be correct. The bolts going through the backing plate, radius rods, and brake bracket should have castle nuts and cotter pins. But if you are not trying to win awards, they should be fine with lock washers provided they are properly tight.
Technically, because the brakes are after-market accessories, lock washers are not necessarily wrong in that location. Lock washers have been around since before the model T and were very common by 1920.
I commend you for spotting this and questioning it in the name of safety. We all have an obligation to maintain and operate our beloved Ts in as safe a manner as we reasonably can.
I also notice that you have functional inside emergency brakes. This is how it should be. Many (most?) RM brakes have been set up without the inside shoes. The one set of brakes are actuated by either the brake pedal or the brake handle. It is bad enough that a minor maladjustment coupled with a part failure can leave a T with no brakes at all with no warning. But RM brakes have serious issues with holding or stopping backwards. With a good secondary/emergency brake, you have a better chance on a hill.
All T drivers should get used to the idea of using that brake handle occasionally. and be ready to grab it in an emergency.
Sorry, I think I drifted a bit.
Drive carefully, and enjoy, W2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Wednesday, September 05, 2012 - 07:22 am:

Bob, I agree with Wayne on all points, but neither of you have mentioned something shown in the first picture. It appears that the inside of the hub has been rubbing on the cap. If that's the case the problem isn't the brake shoe being too wide, it's the hub being close enough to rub. If this were on the right side, that could indicate the infamous babbitt thrust washer problem. But this is the left side. Also, I gather that base has been covered in the thorough going-over this car received when you bought it. A more likely cause in this case is the tapered hole in the hub being worn enough to allow the wheel to go too far onto the axle. I can think of three measures to deal with that. One would be a better hub. After what you've just been through with that wheel, you'd probably prefer another option. That could be one of the new axle shafts that's 1/16" longer than stock. The choice behind the door where Carol Merrill is standing is an 85˘ shim to go on the taper. Being Mister Thrifty, I cut my shim out of an empty can.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hap Tucker on Wednesday, September 05, 2012 - 07:31 am:

Bob,

The above sounds good. I don't remember if you have already checked and confirmed your car has the bronze thrust washers. If not -- recommend you make sure they are not babbit. Note there is one on each side of the axle.

Respectfully submitted,

Hap l9l5 cut off


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith on Wednesday, September 05, 2012 - 09:46 am:

All of those bolts should have castle nuts.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Wednesday, September 05, 2012 - 09:49 am:

And cotter pins.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Richard Bennett on Wednesday, September 05, 2012 - 10:02 am:

Bob, the issue you have is the accessory brakes fitted to the car. The two bolts which hold the radius rods to the diff housing have been replaced with standard longer bolts which are not drilled for split pins and have plain nuts. The pivot bolts are likely to be originals with the usual step down in diameter at the threaded end. These are not standard bolts. When the accessory brake parts are installed on them, there is no longer enough thread exposed to be able to fit a split pin.

I second the notion that you are in need of an axle shim. The wheel looks like it has been going on too far and is rubbing on the grease seal

If you can't get a modern locknut to work on the pivot bolts then a custom made pair of longer ones is in order, so you can drill them and fit a split pin.

Hope this helps.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Treace, North FL on Wednesday, September 05, 2012 - 11:06 am:

Bob

Fitting the R-M accessory brakes on your T required new bolt, lockwashers, and hex nuts. Those will be fine! Lockwashers should be under every nut on a T that isn't a castellated nut, there you would use a cotter pin.

Now to be 'original', not every nut on a T is a castle nut either. Late in '24 the engine to pan bolts even used lockwashers. Good thing, as cotter pins in all those bolts are heck to work with!

If the bolt on the anchor point for the emergency brake shoe won't allow a lockwasher, then what I did was drill 2 holes in the thinner locknut, and then cotter pinned it in place.



Gotta remember that the T will shake off every one of its bolts and nuts if you don't check them from time to time!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Wednesday, September 05, 2012 - 11:20 am:

What was not addressed was the reason why the axle shims are needed with Rocky Mountain Brakes. When you install the large drum on the wheel and then put the small original parking brake drum inside the large drum, you will be moving the parking brake drum inward by the thickness of the large drum. The small drum will be closer to the inside shoes and the nuts will therefore be closer to axle housing. The shim will move things out so everything will be in proper alignment. There is another solution, but more expensive, the installation of longer axles. Some vendors do have longer axles for just this purpose. If your existing axles are otherwise in good condition, the shims will do just fine.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Wednesday, September 05, 2012 - 03:31 pm:

Also being a notorious cheapskate, I make axle shims out of spray paint (rattle) cans. They are made of thin, very tough, steel. They usually work perfect. Besides, that way I don't have to make a phone call and wait for the mail.
Use a piece of paper, wrap it around the axle taper, hold it tight, and squeeze it and press it over all the ends, edges and keyways. When unrolled, it should give you a perfect pattern. Cut and install it just a hair short. You don't want sharp edges cutting the grease seal.
Drive carefully, and enjoy, W2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Coiro on Wednesday, September 05, 2012 - 04:45 pm:

Wayne,
When I pull an ordinary hex-nut and find a bolt with a cotter pin hole, I get a little nervous about the possibility of additional such discrepancies in other vital places. I once found pair of bolts on an aircraft engine that had been safety-wired backwards and a little voice inside told me to have the engine torn down. Sure enough, everything on the inside had been safety-wired backwards.

Steve and Hap,
The evil spectre of a babbitt thrust washer looms, but the gentleman from whom I bought the car rebuilt the rear end for me and said he used bronze. The rubbing and grinding I'm hearing wasn't there before I had the wheel rebuilt. That process involved spray painting the drums with primer and in addition to that fairly thick layer, I, in a state of monumental ignorance, added to it with a couple coats of gloss-black Rustoleum. Add together the layers of paint on both sides of the drums and I probably picked up between 1/32 and 1/16". Can't imagine what in blazes I was thinking. No wonder the parking brake shoes are scraping against the drum (By the way, I had one hell of an adolescent crush on Carol Merrill)!

http://www.carolmerrill.org/

Larry and Steve,
I'm an aircraft guy, so my natural inclination is to agree with you about castle nuts and cotter pins. My feeling has always been that lock nuts, lock washers and star washers are for supermarket shopping carts and Tonka trucks.

Allen,
Steve, at Lang's confirmed what you said about the tapered bolts. He also said that the two forwardmost bolts with lock washers under the nuts are standard and acceptable. Perhaps I'd better let this pair of sleeping dogs lay.

Dan,
I like your elegant idea of simply drilling cotter holes in an ordinary nut. Why didn't I think of that?

Steve, Norman and Wayne,
I ordered some castle nuts this morning (before I saw Dan's neatly-drilled hex-nut). I figured as long as I was paying the shipping on the nuts, it made sense to order a few of those 85-cent shims you mentioned.


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