RPO 684 Rear Springs

[Ken H.]

Hey folks,

Does anyone know if there were differences in the RPO684 rear 5 leaf HD spring design from year to year? I have a single spring from a '58 (see pics on page 2 of the following link) but there are differences on the ones a guy I found is selling. The spacing is different on the 6 clamps, the springs are not "turned up" on the ends, and the stamp of the part # on the bottom, ungrooved spring is in a different place/direction and is not nearly as deep as on the one in the link below. Also, the clamps that the stovebolts go through have holes in the ends, but figured that might have been done to help take the spring apart.

http://s365.photobucket.com/albums/oo91/Remotecontroller1/?action=view&current=IMG_6092.jpg

Anyway, any help would be greatly appreciated.

thanks!!

Ken

[John N.]

Re: RPO 684 Rear Springs

Hey folks,

Does anyone know if there were differences in the RPO684 rear 5 leaf HD spring design from year to year? I have a single spring from a '58 (see pics on page 2 of the following link) but there are differences on the ones a guy I found is selling. The spacing is different on the 6 clamps, the springs are not "turned up" on the ends, and the stamp of the part # on the bottom, ungrooved spring is in a different place/direction and is not nearly as deep as on the one in the link below. Also, the clamps that the stovebolts go through have holes in the ends, but figured that might have been done to help take the spring apart.

http://s365.photobucket.com/albums/oo91/Remotecontroller1/?action=view&current=IMG_6092.jpg

Anyway, any help would be greatly appreciated.

thanks!!

Ken

Ken
There are differences in the RPO684 springs as delivered from St Louis. What is the date code on the spring that you are looking at? What is the serial number or range on your 58?
I have the first 57 RPO684 made #3963 and the bands not only have holes in the end of all bands but the end bands ends are not folded over but the ends are directed toward the ground, then a spacer the width of the springs goes between the ends of the band and finally a bolt goes through the band and spacer. Bill Connells and Joel Laumans (sp) car which was made the next day, I believe had the bolt and spacer on every band. These two cars were being build so they could be raced at Cumberland that weekend and there were a number of parts which Chevrolet grabbed off shelfs to get the cars out the door. I also have 58#1004 which is out of state being restored and I believe that the bands have holes in the ends (by memory which may be wrong). If you do not get definitive answers on the turn up and spacing by Monday PM me and I will look for pictures. Looks like you have a great car to restore.
Regards

[Ken H.]

Re: RPO 684 Rear Springs

Wow - interesting.

Lots to answer here - my car is a march '58 car (I think the 21st of March and is VIN # 5469). I have ONE rear spring that came on the car and it is dated 1/31/08 (as seen in the pic I listed).

The ones in question are dated GM 128 E 7 and the numbering goes accross the bottom leaf (along the axle) rather than length-wise (direction of the frame rail when installed). I believe this would be an early May 1957 date.

On my single spring, the date code is stamped length-wise and the sequence is different (the "E" for Eaton Springs is at the end of the sequence).

Anyway, I will get some pictures and post them so you can see what I am talking about.

Thanks again for the quick response!!

Ken

[Ken H.]

Re: RPO 684 Rear Springs

Ken
There are differences in the RPO684 springs as delivered from St Louis. What is the date code on the spring that you are looking at? What is the serial number or range on your 58?
I have the first 57 RPO684 made #3963 and the bands not only have holes in the end of all bands but the end bands ends are not folded over but the ends are directed toward the ground, then a spacer the width of the springs goes between the ends of the band and finally a bolt goes through the band and spacer. Bill Connells and Joel Laumans (sp) car which was made the next day, I believe had the bolt and spacer on every band. These two cars were being build so they could be raced at Cumberland that weekend and there were a number of parts which Chevrolet grabbed off shelfs to get the cars out the door. I also have 58#1004 which is out of state being restored and I believe that the bands have holes in the ends (by memory which may be wrong). If you do not get definitive answers on the turn up and spacing by Monday PM me and I will look for pictures. Looks like you have a great car to restore.
Regards

John,

When i was talking about the ends being turned up, I am talking about the very end of each spring being curled - when installed the tips of the springs would actually turn down toward the ground. I beleive these springs were supposed to have negative camber just under the normal wieght of the car (per noland's C1 book) so without this curved tip they should tend to dig into each other instead of sliding over each other.

On the bands, they have the holes, but are bent around the bottom of the spring like the ones in the picture of my single spring.

RE: the band spacing, on my '58 spring the bands are close together on one end and spaced further apart on the other end. On the '57 springs in question, both ends are about as tightly spaced as the tighter end on my '58 spring.

Also, at least one of the leafs on each of the springs on the '57 has a wide shovel end. This is not the case with my '58 spring.

In general, I am not sure how many of the Eaton springs from that time had the stovebolts through the bands -

Again, I will get some pics - they really are worth a thousand words.....

Hitting the sack - good night!!!

[John N.]

Re: RPO 684 Rear Springs

John,

When i was talking about the ends being turned up, I am talking about the very end of each spring being curled - when installed the tips of the springs would actually turn down toward the ground. I beleive these springs were supposed to have negative camber just under the normal wieght of the car (per noland's C1 book) so without this curved tip they should tend to dig into each other instead of sliding over each other.

On the bands, they have the holes, but are bent around the bottom of the spring like the ones in the picture of my single spring.

RE: the band spacing, on my '58 spring the bands are close together on one end and spaced further apart on the other end. On the '57 springs in question, both ends are about as tightly spaced as the tighter end on my '58 spring.

Also, at least one of the leafs on each of the springs on the '57 has a wide shovel end. This is not the case with my '58 spring.

In general, I am not sure how many of the Eaton springs from that time had the stovebolts through the bands -

Again, I will get some pics - they really are worth a thousand words.....

Hitting the sack - good night!!!

Ken
Attached are the pictures of the original springs off 57#3963. Hopefully Bill or Franz will take the bait and let the group know the engineering that went into the springs. These springs are unmodified. If you pass on the 57 spring or any 684 or 687 brake drums let me know.
Regards

[John N.]

Re: RPO 684 Rear Springs

Unbelievable!!! I just found pictures of one of the springs off 58 #1004 where I was comparing it to a Chevrolet service replacement and it was stamped on the same day as the 57 #3963 springs (124E7). Although the bands are folded over on 58 #1004 springs, they had the holes drilled in them to support the bolts and spacers.

Regards.

[Bill C.]

Re: RPO 684 Rear Springs

Hi Guys,

John, I don't know how much help I can be. I think both your 684 car and my 579D car were completed on crisis timing for entry at the Cumberland race, and have a number of prototype parts which are not representitive of subsequent production. My springs are similar to yours except all six of my rebound clips (clamps) are of the series 1 bolt design, but also have aluminum spacers known as "mini jounce bumpers'. To my knowledge, our springs, although different from one another, are unique and were probably prototypes that were sourced out of Engineering because the production versions with six clinch clips were not as yet available. While my lettering and date codes are identical to yours, analysis of the design sequence and materials suggests they were actually fabricated in early March. Net, I believe they were stamped when they were shipped, rather than when they were made.I haven't seen the springs on the later cars, but the springs on all the subsequent 1957 production I've seen were the standard six clinch type clips. Hope this helps in some small way. Bill

[Ken H.]

Re: RPO 684 Rear Springs

John and Bill,

Do you guys have e-mail addresses where I can send the photos I took of the springs? I am having trouble with my shutterfly account (won't let me log in) and am hoping to get out photos of these to you guys this evening.

The seller responded to me and said he KNOWS these are original RPO springs and gave me the # of someone to call that can tell me why it is a fact.

That said, the stamping in the bottom leaf is very light compared to the one I have and the photos of yours. Also, the groves in all of ours end sooner (before the clip/strap) where on the sellers they go under the clip. Lastly, the second longest spring has a notched end on it where a strap would look like it is supposed to go - all of the ones we have do not have that notch.

Again - I will get you photos so you can all take a look...

Thanks a million!!!

Ken

THanks!!

Ken

[Justin B.]

Re: RPO 684 Rear Springs

My original Big Brake 1958 VIN # 1327 leaf springs are identical to the original (not service) spring shown here in John Neas pictures...EVEN THE DATE!!!!!!

[Ken H.]

Re: RPO 684 Rear Springs

It is interesting to me that the springs ALL seem to be the same whether cobbled together quickly or for the next model year like Justin's.

I have VIN# 5469 - does anybody here have a '58 RPO car later than mine so we can see what their spring looks like (or even just to confirm that theirs look the same)??

The one spring I have which is dated January 31, 1958 is different that John's, Justin's, Bill's, etc.

See my link above to shutterfly and you will see what I am talking about.

Thanks,

Ken

[Ken H.]

Re: RPO 684 Rear Springs

OK folks - I was able to get into photobucket - here is a link to one of the pics and the rest should be adjacent to it.

Please let me know what you think.

Thanks again!!

Ken

http://s365.photobucket.com/albums/oo91/Remotecontroller1/?action=view&current=IMG_6924.jpg

[Ken H.]

Re: RPO 684 Rear Springs

Bump

John, Bill, etc. -- if you can take a look at these and let me know your opinion I would really appreciate it - I need to make a decision on whether or not to keep these springs.

Thanks!!

Ken

[John N.]

Re: RPO 684 Rear Springs

Bump

John, Bill, etc. -- if you can take a look at these and let me know your opinion I would really appreciate it - I need to make a decision on whether or not to keep these springs.

Thanks!!

Ken

Ken
My opinion would be that the jury is not in yet. I would take a good caliper and measure your real 58 spring leafs and compare it to the individual spring leafs of the two 57 springs you are thinking about buying. Then I would contact Franz if he is available and show him the pictures and give him the measurements.
The bands on the 57 springs look like they could be proper for the May 57 springs. The bottom spring stamping looks correct (you might compare the font to my pictures) but it looks like it spent time in a salt water marsh in Florida. That leaf with the notch looks questionable. I believe that the springs because of hard usage were subject to breaking a leaf or two. My 57 had one broken leaf and my 58 had two. Both cars spent their weekends having fun racing. I am still looking for several leafs. The 57 springs may be correct or partially correct ie could be springs that were restored with some incorrect leafs.
Regards

[John N.]

Re: RPO 684 Rear Springs

For discussion.
It appears based on the input that the date stamping on springs may not be the day that the springs were produced or the day that they went out the door at Eaton. We believe that at least two sets (each with somewhat different configuration were produced several months before they were stamped and went out the door and then on the day they were stamped another 100 to 150 sets were made. Could the stamp date be related to the PO date?
Regards

[Ken H.]

Re: RPO 684 Rear Springs

John,

Can you tell me who Franz is??

Also, where would you recommend I take the measurements from?? Should I only compare to the spring I have or should I go ahead and post the measurements here??

On my single '58 spring, does the stamp seem correct (again, it would be great if there is another RPO car with springs dated around or after January '58 to compare to)?? It is facing a different way and the sequence is different (the "E" for Eaton Springs is in a different place than it is for all of your springs)?

Thanks again,

Ken