Radius Rod to Backing Plate Bolts not tight
 

I recently changed a rear axle and when I removed the backing plate the front bolts on the backing plate that are connected to the radius rod were loose (the bolt could be turned with the nut tight) . After changing the axle, when I replaced the backing plate those bolts even when tightened all the way down are not tight, and can be turned even after putting a cotter key in the proper position on the nut. These bolts are from Snyder's. If the front two bolts that go through the radius rods are not suppose to move after tightening all the way, then I have a problem and somehow need to shim something to allow for them to be tightened. The rear two attaching to the axle housing tighten fine.

Re: Radius Rod to Backing Plate Bolts not tight
 

In the 30 years that I have been involved with Model A's I have seen this problem since day one. No one has ever been able to answer the question why. The first Model A I had all the rear backing plate holes were worn into the shape of a football from rocking back and forth because the bolts and nuts were bottoming out and not holding the backing plate tight. Some have speculated that it is because of reproduction parts. That is not the answer, I have a whole box full of original bolts. Others have said it is due to wear. I don't think that is the answer either.


What I have done to solve the problem is I obtained some thin washers that fit the bolts and have a small outside diameter. I stack a quantity on each of the four bolts on each of the back wheels between the backing plate and the D-shaped grease slinger enough to ensure that the bolt and nut are tight along with the backing plate. I have to do this to countless numbers of Model A's.


I have seen the D-shaped grease slingers at swap meets that have a washer tacked to the back side of each bolt hole. However they are too thick for Model A application, I suspect they are for the early V-8's.


If some one has the answer for the reason for this problem I would like to hear it.


Tom Endy

Re: Radius Rod to Backing Plate Bolts not tight
 

I have always used a washer under the head of the bolt just to ensure that I can get a good tight fit and still get the cotter pin to seat correctly.

Re: Radius Rod to Backing Plate Bolts not tight
 

As a follow up to my post above, the attached article explains how I address the problem of loose rear backing plate bolts.


Tom Endy

Re: Radius Rod to Backing Plate Bolts not tight
 

Tom thank you for the information. I am beginning to reinstall me backing plates and have the same issue. I’m going to try the washer solution.

Re: Radius Rod to Backing Plate Bolts not tight
 

Problem might be with the A-2240 Brake Grease Baffle Rear.

There were two versions:

THe original version used a sleeve on this plate for each bolt that was fastened to the grease baffle. These used the longer bolts.

THe new version deleted the sleeves and you need to use shorter bolts. If longer original bolts are used the bolts will never tighten.

Here is photo of new version that uses shorter bolts.

https://parts.modelastore.com/show_Product.asp?ID=3156

I believe that these new plates require the shouldered nuts shown here:

https://parts.modelastore.com/show_Product.asp?ID=3157

I have photo somewhere that shows old and new baffles side by side but can not find it just now.

Re: Radius Rod to Backing Plate Bolts not tight
 

Grease baffle, is a good point. Also, over the years the recess at the end of the nut gets worn. If you look at the nut you will see there should be a clear area, no threads, that fits down around the shoulder of the bolt. If this area gets smooshed or is missing the nut will stop before it pulls everything together.

Re: Radius Rod to Backing Plate Bolts not tight
 

Here is a picture of my e-brake carrier and baffle.

Notice the spacers between the two parts...

Re: Radius Rod to Backing Plate Bolts not tight
 

Yes that is the original style.

The spacers are spot welded or somehow fastened to plate on original.

Re: Radius Rod to Backing Plate Bolts not tight
 

Here is original baffle photo uses longer bolts

To see new style that uses shorter bolts ... look at link on post 6 above.

Re: Radius Rod to Backing Plate Bolts not tight
 

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Re: Radius Rod to Backing Plate Bolts not tight
 

Thanks for all the help on this post. Since the back two bolts attaching the backing plates were tight on both sides, I elected to do as CarlG had done and placed a washer under the head of the front bolts. By doing this I was able to tighten the front bolts completely.
Thanks again for the help.

Re: Radius Rod to Backing Plate Bolts not tight
 

Ditto. I was wondering why my car had two thick washers under those front bolts, now I know!

Re: Radius Rod to Backing Plate Bolts not tight
 

I can't take credit for this idea, but when I encountered the same concern of loose rear backing plate bolts, I was advised to use a conical wheel lug washer under each castle nut. It worked like a charm.

Re: Radius Rod to Backing Plate Bolts not tight
 

Thanks to everyone for your excellent posts, very helpful. I dug around in my parts pile and found one of each type, so I'll clean up the one with spacers and finish the side I'm working on so I can use the long bolts I already have. I don't know what I'll see on the other side when I get to that, but I may have to find another baffle with the spacers on it. Thanks again! -DAN

Re: Radius Rod to Backing Plate Bolts not tight
 

POST 6 above the PHOTO links error out


Berts website was updated and so links are bad.


I am not allowed to correct these links so this is next best...


Here are the two photos involved:

Hopefully these photos will be good for a while! I think they are JPEGs ...