C2 1963 Rear Spring Cushion washers

[Richard G.]

I have been working on the rear suspension, of my 63 SWC, and messed up one of the washers that is staked to the trailing arm. This was the last of the four I installed. (I am not quite sure why the hole is so much bigger than the washer) So I ordered another. The mistake I made is I used a different vendor with out thinking of the consequences. After waiting 6 days for my order the washers arrived. I was astounded to find the washers had a different finish than the first set. The Volunteer Vette washers were zinc coated and the Paragon washers were phosphate. I have a 1963 and I doubt GM changed the finish on the washers over time but I could be incorrect. So which ones do I use? I could pull the three zinc washers I have installed and use the replacement Phosphate washers or order a matching one from the original vendor.
Thanks
Rick

[Gary B.]

Re: C2 1963 Rear Spring Cushion washers

Rick,

When you say "washers" are you talking about the bushing retainer cups that are swaged in place, as discussed by Fred Yankocy in his thread from a few days ago?

Gary

[Joe R.]

Re: C2 1963 Rear Spring Cushion washers

Both the cups and the washers were either natural of black phosphate.

Neither were bright zinc.

JR

[Gary B.]

Re: C2 1963 Rear Spring Cushion washers

JR,

This is the first I've ever heard of the 3831588 retainer cup being black phosphate.

Gary

[Richard G.]

Re: C2 1963 Rear Spring Cushion washers

Yes, I am referring to the bushing retainer cups that are swagged in place.
I did do a search and didn't find the information.
Did check Fred Yankocy post using you suggetion.
Stated the cups should be natural finish.
The Paragon washers were closer to natural looking.
My description might be off as I didn't remove them from the packaging.
I will get a picture and post it soon.
Thanks again for everyone's help.
Sure makes this difficult process 100 times easier.

[Gary B.]

Re: C2 1963 Rear Spring Cushion washers

Rick,

I'm pretty sure the retainer cups sold by Long Island are zinc plated, which is definitely not correct. Diluted muriatic acid that is sold in many hardware stores can be used to remove the zinc plating.

Is the spring you're installing the cups in an original spring? Or a repro?

Also, does Paragon sell the early style cups (for '63 thru early '67) with the less steep peripheral lip?

Gary

[Joe L.]

Re: C2 1963 Rear Spring Cushion washers

Yes, I am referring to the bushing retainer cups that are swagged in place.
I did do a search and didn't find the information.
Did check Fred Yankocy post using you suggetion.
Stated the cups should be natural finish.
The Paragon washers were closer to natural looking.
My description might be off as I didn't remove them from the packaging.
I will get a picture and post it soon.
Thanks again for everyone's help.
Sure makes this difficult process 100 times easier.

Richard------


While the original retainers, both the swaged in cups (inner retainers) AND the large washer-like retainers (outer retainers) were originally natural steel, I don't think it's a bad idea to use replacements which are zinc plated. The originals will rust quickly. So, I'd forego this nuance of originality in favor of rust-prevention. Rusty retainers are not original, either. In fact, if these retainers, both inner and outer, were available in stainless steel, I'd use them without a second thought.

By the way, some folks coat the spring-mounted inner retainers with the gray coating used on the bottom of the spring leaves. This prevents corrosion but it's also incorrect. The retainers were installed at St. Louis, long after the spring leaves were coated at the spring manufacturer.

[Richard G.]

Re: C2 1963 Rear Spring Cushion washers

I wish I could rename this post cushion retainer to avoid any confusion.

Here is the picture, of the two cushions.



The zinc cushion was supposedly correct for early cars, with less of a rise in the punched out center area.
That was the reason I purchased them, other companies didn't differentiate between early and late C2's. Some time later GM added to this area for an obvious reason, allowing for a better crimp. I believe it would be is almost impossible to tell how long the cushion was after it is flared during the crimping process. IMHO one would be less likely to loose points on the retainer's finish than the crimp, so I am going to remove the zinc plated retainers and replace them with the cushion retainers closest to natural finish.
Still can't identify exactly what finish, if any, is applied to the cushion retainer. I called it phosphate, but I could be incorrect.

I would recommend the short rise (early style be avoided). The obvious plating discrepancy and the lack of material in the area of the flair. If the zinc would have had the extra material, in the center, I am confident the install would have worked better. Most of us know the size difference between the flared cushion retainer OD and the holes in the spring and trailing arms is significant. The extra material on the cushion retainers will help retain the cushion retainers. I will post pictures of both crimps later today.
Rick

[Gary B.]

Re: C2 1963 Rear Spring Cushion washers

Rick,

Knowledgeable chassis judges will look for the height and slope of the peripheral lip and take a deduct if the later style cup (GM#3910701) is used on 63-early 67 cars.

The challenge to crimp the early style cups with the shorter collar to be crimped has been discussed on the DB previously. That challenge is greater if using a repro spring with a thicker main leaf and/or a larger hole in the spring.

Gary

[Richard G.]

Re: C2 1963 Rear Spring Cushion washers

Everyone; thanks for the comments and input. Much appreciated.

I just identified another difference.
The outside diameter of retainer's flared hole.




I tried my best to get on an original section of the previously flared retainer.
Their is a nominal .080 to .090 difference in the outside diameters.
Should have a uninstalled retainer to confirm this. But the diameter should be bigger, not smaller, because of the install.
Even before the tool was installed I noticed the new retainer (without the zinc finish) fit the holes much better.
In my opinion this is the reason the last flare I attempted failed.

Per: Gary's comments:

Knowledgeable chassis judges will look for the height and slope of the peripheral lip and take a deduct if the later style cup (GM#3910701) is used on 63-early 67 cars.

I will get pictures the top edges, side by side, sometime later today. I am not sure what exact style I have.
Paragon list the part this way;

Rear trailing arm & rear spring cup, correct OEM style, (1) pc.Years: 1963 - 1966

Possibly I am confusing early and late descriptions given in the catalog. Confusing the length of the "to be flared section" with the peripheral lip on the rubber bushing side as the definition of the early and late versions of this part.

Right now I much prefer the Paragon version. As the finish is closer to a natural finish as described in the judging manual and the larger outside diameter of the flared section fits the hole so much better. Also the extended flared section that allows for a much better crimp.

The installation tool works great on the trailing-arms. I had issues with the spring retainer moving out as I attempted to flare the retainer that goes onto the spring. I went to the press and used only the flared section of the tool (sans the bolt) This gave me a crimp I was happy with.
Going to spend much the day getting this one item correct. Crazy isn't it!
Rick

[Gary B.]

Re: C2 1963 Rear Spring Cushion washers

Rick,

Where did you buy the cup that was black phosphate?

And when you say the "installation tool works great", where did you get the installation tool? Is it the one that some of the catalog companies, like Corvette Central or Ecklers, sell for $45 or so?

Gary

[Richard G.]

Re: C2 1963 Rear Spring Cushion washers

Where did you buy the cup that was black phosphate?

Paragon was the source;
Might be gray phosphate?
Well I kind of guessed, at the finish.
I had only inspected it through the plastic when I wrote the first post, as I wasn't sure I was going to use them....
Still not absolutely sure of the finish type.
Something is there it is not raw steel, which would rust while you looked at it.
Note; the Paragon sourced washer would actually stay in the hole once it was fitted. I kind of had to pop them in.
Zinc plated one were so loose it was pathetic. +

Interesting, to me, that none of the vendor's web sites cushion description addressed the finish type.

Corvette Central is the tool supplier.
REAR SPRING CUP INSTALLATION TOOL ( FOR REAR TRAILING / CONTROL ARM OR REAR SPRING
Item#:582219 Price: $39.95

I have included a couple pictures of the install on the spring using a press. The kit worked well on the trailing arms, well designed and the section of the tool that completes the flare is extremely hard. Fasteners are grade 8. Nice tool in my opinion. Only issue was holding the washer down. Might have been OK if I would have continued to tighten the bolt and flair the cushion. I didn't was to take a chance as I had already messed one up.

[Gary B.]

Re: C2 1963 Rear Spring Cushion washers

Rick,

Black phosphate is typically somewhere between medium to dark gray, so don't get hung up on the "black" term. The cup in your photo looks to me to be black phosphate treated.

Long Island was the first company to repro the '63-early '67 cups, starting 3 or 4 years if I recall correctly. I have some of the LIC repro cups and they are zinc (or silver cad) plated. I can't guess why Paragon chose black phosphate and LIC chose zinc. I've never seen an NOS example of the '63-early '67 retainer cups, but the consensus is they were natural, just like the later style cups with the taller, steeper peripheral lip that was used starting around January of '67 and onward (GM #3910701, which was sold until a year ago when it was GM-discontinued). The GM 3910701 cups sold as service replacement parts look exactly like you'd expect for a natural, bare steel part, i.e., not zinc plated and not black phosphate.

Gary

[Richard G.]

Re: C2 1963 Rear Spring Cushion washers

Thanks to Gary and everyone that replied.
I leaned a lot today.
Only real cost was $10 for the retainers I trashed.
Not much on these cars that cost less than that!

Rick