The Stovebolt Site Forums The Shop Area Engine Shop Anchor pin washer location

Hello folks. I've searched the archives but no luck. I'm doing the rear brakes on my '51 3100. The anchor pin at top of the backing plate has 2 washers. One is a regular old lock washer (split and offset so it puts tension on the nut when tightened down). The other washer is shaped like the anchor pin shaft--curved on two sides and straight on two sides--to help keep the anchor pin from rotating.

Here's the question: Clearly, the lock washer goes with the nut on the back side of the backing plate, but on which side of the backing plate does the shaped washer go? On the right wheel, the shaped washer was on the back side of the backing plate, between the lock washer and the backing plate. On the left wheel, the washer was on the shoe side of the backing plate, between the backing plate and the anchor pin "flange".

A clue: the wheel cylinders are supposed to be 1 inch diameter, but the one on the left wheel is 15/16", indicating to me that somebody has worked on this wheel. That would tell me it's likely the anchor pin was removed and possibly replaced with the washer on the wrong side of the backing plate. On the other hand, on a 57-year old truck, both sides have probably been worked on several times, so there's no telling which side is right.

So whadya think? Does the washer with the hole shaped like the anchor pin shaft go on the inside or outside of the backing plate? It makes a difference, because it changes the location of the anchor pin by the width of the washer.

Thanks!

D.J. do you have a shop manual and a factory assembly book? Mine is out in the garage but I would think one of those would give you a picture example of the brake set-up.

Thanks Big Chevy. I have a shop manual, but it doesn't go into that level of detail. I'll look into getting a factory assembly book. I don't think this is a critical issue, but I'd like to get it right while I have things torn apart.

I think I'd be more concerned about the difference in cylinder diameter. Even a 1/16" difference will result in unequal braking effect from side to side, since the cross-sectional area of the pistons will be different. I'd strongly suggest going back to original-equipment size, if at all possible!
Jerry

If the washer is soft I believe is goes on the inside & one end bends around the bolt to lock it.

Thanks for the advice, Hotrod. My auto parts guy made the same comment. I hadn't realized it was a problem, but he assures me there will be uneven braking. I guess I'm in the market for a 1" wheel cylinder.

The washer your talking about goes right on the spring holder doohickey, right before you slide it through the backing plate. When you put it together youll see how it works. If my memory serves me correct there is a recess in the backing plate where it sits. Once that spring holder is pushed through the backing plate, there should be a machine bushing (kinda like a washer) and a lock washer, then the nut.

Hope that clarifies it.

Jeff

Oops, you dont need the machine bushing, I added it as I use star washers as opposed to using the regular type of lock washer.