Safety washers for rod ends

[Terry Kennedy]

A number of race rule books require safety washers on rod ends. Even if you aren't planning on running in those races, safety washers are an inexpensive, easy-to-install option for your Atom.

Safety washers should be used wherever a separation of the spherical bearing from the rod end race would lead to separation of the parts. In brief, that means that wherever one side of the rod end has only a bolt head, you should use a safety washer. In cases where the rod end is held in a flange, you don't need a safety washer.

On the Brammo Atom, there are 6 places where safety washers are needed - four 5/8" washers, one at the top of each upright, and two 3/8" washers, one on each outboard end of the steering pushrods. The rod end at the bottom rear of the rear uprights doesn't need a safety washer as the mounting of the upright means that the rod end spherical bearing can't separate.

I used the SW58S ($2.85 each) and SW38S ($2.31 each) stainless steel washers from Meziere Enterprises, though there are many other vendors out there.

One thing to be aware of is that the bolts that go through the rod ends may not be long enough to deal with the added thickness of the safety washers. In my case, I needed to use longer bolts on the uprights - changing from the stock 5/8-18 x 1 1/2" socket head cap screws to 1 3/4" parts. This is a rather oddball size and may be hard to find. Bolt Depot has them for $1.50 each, though they are marked as "not always in stock". This part is not drilled for safety wire, so you'll need to drill the head yourself. You can also order this bolt from Tom at Unique Fabricating, pre-drilled for safety wire. Contact Tom for pricing and lead time.

For the steering pushrods, you can re-use the existing bolt. As installed by Brammo, from the top down the sequence is: bolt head / thin washer / rod end / thick washer / upright / thin washer / nut. When using the safety washer, assemble like this: bolt head / safety washer / rod end / thin washer / upright / thin washer / nut. You'll have a thick washer left over.

Here's what the completed assembly looks like (front left - front right will be the same, rears will only have the large safety washer):

EDIT: Do not use this method - see later replies for alternative methods

[Heywood-Yablowme]

Very nice!

[Terry Kennedy]

[quote="Spanky"]
  I would like to suggest that you check out what that safety wire is going to do when you move the wheel thru its' full steering range. I once tried wiring mine like in your photo, but the wire was being twisted back and forth as I turned left and right. It was real easy to see what it does when I had the front wheels lifted off the ground and moved them back & forth by hand as I watched the wire. If I am not mistaken, your wire as shown in the photo is attached to the a-arm that does not rotate. The bolt head does. This will probably fatigue the wire to the point of at least stetching some so that it will no longer serve its' purpose. 
[/quote]

Good catch! I'll change it back to the Brammo style of securing it around the smaller bolt.

[1965Cobra427]

[quote="Terry Kennedy"]

Good catch!

[/quote]

[Terry Kennedy]

[quote="Terry Kennedy"]
Good catch! I'll change it back to the Brammo style of securing it around the smaller bolt.
[/quote]

I tried using the Brammo method, but wasn't happy with it. I re-installed the thicker washer between the rod end and the upright (my original post said to use a thin washer there), and it looked like this:



I didn't like the way the safety wire could be pinched and damaged when the small rod end rotated. So I came up with another method which I would appreciate your comments on:



This ties the safety wire around the back fender support. As this piece does not rotate relative to the large cap screw, there is no flexing of the safety wire. I cut a silicone bushing (the same part used for the muffler mount) and slid it around the fender support to keep the safety wire from wearing through the finish. There's a groove in the silicone washer and that's where the safety wire sits.

Obviously, this method won't work if you remove your fenders (unless you have the Sector 111 fender quick disconnect kit). But I don't see any other drawbacks to this method. Any comments / suggestions?

[Terry Kennedy]

[quote="Terry Kennedy"]
This ties the safety wire around the back fender support. As this piece does not rotate relative to the large cap screw, there is no flexing of the safety wire. I cut a silicone bushing (the same part used for the muffler mount) and slid it around the fender support to keep the safety wire from wearing through the finish. There's a groove in the silicone washer and that's where the safety wire sits.[/quote]

I decided I didn't like that method either. I ordered some 2-3/4" length 3/8-24 18-8 stainless hex head cap screws (McMaster 92198A367) and proceeded to have a very difficult time drilling the heads for safety wire. Even with a special drilling jig and exotic drill bits, I don't recommend doing this. Pay somebody to do it for you (I bet Tom Smurzynski could).

I re-installed the thicker washer between the rod end and the upright. I also used new Nylon locknuts (McMaster 91831A130).

Lastly, I wasn't happy with the very limited freedom on the steering pushrods when using the Aurora PRM/PRB-6 rod ends. While the standard Aurora AM/AB-6 rod ends allow a misalignment angle of 12 degrees, the PRM/PRB-6 have an allowable misalignment of only 8 degrees. This didn't allow much freedom of rotation at all on the steering pushrod. If forces act on it to turn it beyond its free range of motion, this is going to cause one of the rod ends to loosen. And if the jam nut loosens due to this, bad things could happen...

So I consulted with Aurora and they suggested the CM/CB-6ET part, which allows 22 degrees of misalignment. Note that this is the "ET" version of the part, not the non-ET version, which has a much lower load rating. This part is not stocked by Hoerr Racing (Aurora's recommended dealer), but they can special order it with a day or two of notice.

So, after I got it all reassembled, it looks like this:

[Heywood-Yablowme]

I have noticed the binding in the extreme ends of the steering travel,and dismissed it because the steering is almost never at those ends,unless you are travelling quite slow. However,since there is a solution,I will be changing them out to the 22 degree units. After all,I did have a steering rod end come apart on me...    Might actually hit those ends on some A/X courses..

Thanks for posting this,Terry.

[Terry Kennedy]

[quote="Curator"]
I have noticed the binding in the extreme ends of the steering travel,and dismissed it because the steering is almost never at those ends,unless you are travelling quite slow.[/quote]

That may or not be related. The best way to tell is to try rotating the steering pushrod with the wheels all the way to the left, centered, and all the way to the right. If there isn't a reasonable amount of play, then the ET rod ends should help. There shouldn't be a problem if people have the AM/AB rod ends and no safety washers. I think the combination of the PRM/PRB rod ends and the safety washers further limited the possible misalignment.

EDIT: Another thing - it is possible to tighten down the rod end jam nuts so that one rod end is near one side of its misalignment and the other rod end is at the other side of its misalignment, thus reducing the amount of possible rotation of the steering pushrod. That's easy to check - both rod ends should be parallel to their respective mounting hardware at the same time.

One other thing. I don't know if any of your Atoms were built early enough to be affected by this issue, but early Brammo Atoms had collar stops installed under the the steering rack bellows / gaiters / whatever-you-call-em's. This was because the front fender supports would hit the steering pushrods before the end of the steering rack's travel. So the collar stops were installed to limit the turning radius.

EDIT: I see that your earliest Atom is #39, so this shouldn't apply to you.

I purchased upgraded front fenders from Brammo which didn't have this problem, and which were used on later Atoms, and took the collar stops off.