Topic: Time for New Rear Springs

[FredG]

Ok,
I know this topic has been beat to death and I'm still up in the air over this, but its time to replace the rear springs in my 66 (6S1826 - black/gold Hertz) and I'm wondering if anyone has any RECENT experience to share after buying rear springs. 

I have the following:
Two correct original bottom leafs.
Correct repro bands.
Correct longer center bolts.
(I fully expect to have to reshape the ends/edges of whatever new springs I eventually use)

Given all the nightmare stories about incorrect ride heights for "factory correct repro springs", what I would like to avoid is having to remove brand new springs for de-arching after installation should they hold the back of the car up higher from what be considered "normal" or original ride height.  Restoration is concours, Wheel and tire size (14") will be as close to original as possible.   
Thanks,
Fred

[Rsanter]

If it is going to be concourse and not driven much, what about re-arcing the original springs

Bob

[CharlesTurner]

If you want new, about the only option is going with the Eaton leaf springs and installing the original lower leaf. 

[FredG]

Bob, while I can't fully disagree with you, I really did not want to go with 48 year old springs.  Although I'm restoring to concours, car will be locally driven.  Charles, thanks for the response and you sort of confirm what I was thinking....basically that Eaton might be the lessor of the evils..?
Fred

[Paperback Writer]

I had a similar dilemma when restoring my ’67 Convertible last year – restore the originals or buy replacements?  However, after disassembling the original rear leaf springs, it became quite apparent that the car would need new springs...

So using the “OE DESIGN LEAF SPRINGS” chart in the NPD catalog, I determined that my car (a 390 GTA Convertible) would require the #5560-25 Eaton springs rated at 135lbs (your car will probably use different springs).  After they arrived, I wasted several days trying to get the black coating off of them (and I also noticed when I disassembled them that despite the coating, there was already some rust forming between the leaves!).  BTW - don’t even bother trying to use heat guns, acetone, aircraft paint stripper, or a wire wheel on them - the black coating is impervious to all of these...

As has been mentioned many times on this and other forums, the bottom (shortest) leaves on the Eaton springs are totally inaccurate, but the other three do an okay job of mimicking the originals.  The shortest leaves of the originals also have the Ford part numbers on them, so definitely restore and reinstall them if all possible – it sounds like you’re already good to go there...

I also soaked my bottom leaves in Evaporust to find the factory paint markings - although not all factories paint marked their springs on the bottom leaves...

[Paperback Writer]

Back to the black coating - I finally had to take them down to the restoration shop that was doing the bodywork on my car, and borrow their bead-blaster to get that all that stuff off.  I then tried brushing some gun blue on them to darken them up a little.  They looked great for about 15 minutes, and then started to flash rust rather badly!

So I cleaned off the rust with some more Evaporust, and tried the gun blue again - but this time I hit them with some WD40 almost immediately after the gun blue, and they stayed a nice dark metal color without any rusting...

I then coated all sides of each leaf with Rust Prevention Magic (RPM) and took them to a spring shop to have the correct circle hole clamps, front bushings, and insulators installed...

After that, I cleaned the RPM off of the rear portions of the bottom leaves so I could apply my green and white paint markings (2018 update: the paint markings should be green and silver).  I know, they aren’t as “sloppy” as the original Ford markings, but I like them anyway.  After the paint markings dried, I re-coated the bottom leaves with RPM and took them to the restoration shop for re-installation on the car...

So how do they perform?  I thought they were perhaps a tad high when first installed, but after putting the spare tire in the trunk, adding a full tank of gas, and driving the car for about 800 miles, I think the springs have settled nicely, and the stance of the car looks pretty good now - and so far I have not seen any rust on the springs either (although I must admit that the car has never been driven on wet roads - yet)...

Hope this helps!

[67gta289]

FYI if you order direct from Eaton Detroit Spring you can ask them to dissassemble and shot blast the leafs.  Shot blasting is much preferred for spring steel.  Then you can apply gun blue, RPM, etc. and reassemble.  I had them do mine, and they did my original coil springs also at a small fee.

http://www.eatondetroitspring.com/

[FredG]

Hey Paperback,
Tnx for the response. This was exactly the info I was hoping to learn.  BTW, your car looks beautiful.   Question, the shot after 800 miles...its a little hard to tell from the camera angle, but does it seem that the rear of the car is down about 1" or so from when you first installed the springs? Also, is there an advantage for buying from NPD vs direct from Eaton Spring?
Thanks
Fred

[FredG]

67GTA
Thanks, looks like we posted at the same time!
Fred

[69bossnine]

is there an advantage for buying from NPD vs direct from Eaton Spring?

Hi Fred,

Our retail price is actually a bit less than what you'd pay going direct with Eaton, and we keep all of the springs in-stock at all times for same-day shipment.

If you have special needs, or want a non-stock application, that's when it's usually best to call up Eaton directly..

Rick
NPD

[Paperback Writer]

Thanks for the compliment on my car Fred!

I think John and Rick both offer good reasons for when to buy from NPD and when to buy from Eaton directly.  In my case, I was already ordering a bunch of other parts from NPD at the time, so the rear springs were just another item to add to the list...

Regarding the rear ride height of my car: yeah, I think the springs have probably dropped about an inch, but that's only an anecdotal observation - unfortunately, I didn't have the foresight to take any sort of measurements when the springs were first installed...

However, I did check the 1967 Mustang Shop Manual, and it says that the Rear Spring Rear Hanger Hole should be 15.57 inches off the ground.  I measured my car this morning, and the rear hanger hole is about 14.75 inches, so I guess my car is sitting a little lower than stock in the back - but this could also be partially attributed to the tires, as the 225/60R15's that I'm using have a diameter (or height) of 25.6", while the original Firestone F70-14's had a diameter of 26.2" (and radials usually sit lower than bias ply tires as well)...

[FredG]

Paperback,
Again, thanks for the response.  All along I was thinking that the tire circumference may have been adding to the illusion that the car may be sitting higher than normal ride height. Well. obviously bias tires on the street are not worth it, but settled out now after 800 miles, your car looks really nice.  Thanks Rick also for the response. BTW, prior to becoming obsessed by the spring thing, I never really gave gun bluing too much thought.  Holy crap, now I'm finding, hot blue, cold blue, rust blue., no rust blue, distilled water boil, no boil, liquid, paste! Yikes.. I think I got a take a chill pill! 

[J_Speegle]

Paperback,
Again, thanks for the response.  All along I was thinking that the tire circumference may have been adding to the illusion that the car may be sitting higher than normal ride height. Well. obviously bias tires on the street are not worth it, but settled out now after 800 miles, your car looks really nice.  Thanks Rick also for the response. BTW, prior to becoming obsessed by the spring thing, I never really gave gun bluing too much thought.  Holy crap, now I'm finding, hot blue, cold blue, rust blue., no rust blue, distilled water boil, no boil, liquid, paste! Yikes.. I think I got a take a chill pill!

For big things like leaf springs you might want to try something like Insta-black rather than gun bluing. Found its hard to get a consistent finish on such a large- long part

[FredG]

Thanks Jeff, will check it out.
Fred

[Linc]

This thread has been very enlightening and I am considering much of what I read here to refinish my springs. However,
I have a question about the reproduction springs verses what is actually in my car. I have an early 67 Fastback and
my original springs are C7ZA AS.  I bought springs from Summit Racing because the price was better and they were Scott
Drake reproductions that said they were for my car. Based on what I have read I was certain I would have to use my
original bottom leaf for the part number. But what I didn't expect was that my other leafs are different as well. In the
other posts in this thread you all seem to have the same springs that Scott Drake reproduced, but I don't. Can anyone
help me understand why mine are different and if I can get that type or if I should just use the Scott Drake ones. It would
bug me forever that they were not right, but I am not a millionaire either. Also my clamps are slightly different as well.

Pictures of my springs and the reproductions.