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'31 Chrysler CD8, suspension ?'s

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I am disassembling the suspension pieces for my '31 Chrysler CD8 Roadster, the car was rebuilt in 1952 using whatever was available, so I am somewhat blindly forging ahead. I have a few questions


1. The shackle bolts in the rear and the bushings/silent blocks, appear to be original and bolts are siezed in bushings. Any advice on just how to free up the bolts so they can be knocked out and then advice on how to press the bushings out. I believe I can get replacement bushings/blocks and bolts locally (Parts for Trucks outlet).

2. The front springs have had some relatively minor modifications made to them which I can clean up. My primary ?'s are how to properly fit them to the axle pad, it is dead flat while bottom of spring is curved? Was there some sort of curved saddle they sat in originally? Or were original springs flat at center point (these springs appear to have had a short curved extra leaf added to bottom).

3. Also I note axle pad (I believe axle is from a '33 Chrysler) has no extra hole for securing a shock absorber? Any thoughts? 

4. The U bolts were bolted directly onto springs with no means on top of spring of holding the bolts from sliding potentially. Most applications I have seen show some sort of clip/saddle fitted over the center bolt that holds the U bolts. This piece also often has a rubber bumper in some cases. Anyone know what I am supposed to have here?

5. While rear springs appear to be original CD8, the rearend is from a '34/35 Auburn. I may swap it out. My question is whether the spring mounting plate through which the U bolts fasten appears to be proper Chrysler CD8? It has a hole for fixing a shock absorber arm, the brackets are possibly mixed left versus right, not a big deal. I don't have a proper rear end yet so don't know if Chrysler axle housing is same diameter as the Auburn one at this pointpost-108496-0-69423600-1433463938_thumb.post-108496-0-68308900-1433463956_thumb.post-108496-0-07290900-1433463990_thumb.post-108496-0-48673900-1433464023_thumb.?

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This is based on my 32 Dodge, but most Chrysler products seem to have a similar setup.  My 29 Plymouth was like my Dodge, minus the shock absorbers.


These are the parts to attach the front axle - The spring pads, the bottom plates and the U-brackets (in this case the square brackets).  You can see the extra hole for the shock mount on the plates.  The bottom plates don't really do anything but provide a mount for the shock arm.  They mount to the front of the spring and the front of the brackets.






The base of the front springs has a slight curve to the smallest leaf, but the axle and the bottom plate flatten that out when everything is bolted together.





You can see the curve in this shot of the disassembled springs - it's supposed to be there.




With the spring assembled, it tends to flatten out a bit, but there is still a curve to it.






This is the assembled front end.  The combination of the bottom plate and the U-brackets pull everything together.  The spring bumper pads are sandwiched between the brackets and the top of the spring.  As to the brackets sliding, there should be a hole in the top of the axle where the head of the center bolt in the spring drops into.  This keeps the spring from sliding on the axle.




As to the rear springs, getting those bolts out was one of the most difficult things I've gone through during my restoration.  One came out with a bit of gentle persuasion, but the other refused to budge no matter what I tried.  I was initially afraid that the bushings would not be available and was worried heating them would destroy them.  To further complicate matters, the section of the bolt that needs whacking faces in toward the frame and there is no room to get leverage or swing a hammer.  I quickly learned that once these bolts rust to the inner metal sleeve of the bushing, you are not going to get them out. 




I finally used a small cut-off wheel to cut the bolt on each side so I could remove the spring.  I had to make the cuts inside since grinding off the head of the bolt and the protruding opposite side would still have left the remainder of the bolt hung up in the housing.  It was a tricky job since I didn't want to damage the frame housing.  Use a small wheel and exercise a lot of patience.




When I took the springs to a local spring shop to have them checked out, I was pleasantly surprised that they had the correct bushings in stock and I had them remove the old bushings and press the new ones in for a nominal charge.  They also had new bolts.  These bushings are apparently still used on some trucks.



Edited by Taylormade (see edit history)
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Chrysler may be an exception, but all Chrysler products from this era that I have examined have Tryon spring shackles, a rather distinctive shackle to say the least.  They use a circular spring/washer to maintain correct spacing.


I found some at Hershey a few years ago, but it turned out the shackles on my car were in excellent shape and I just used the new hardware off the NOS kits that I bought.








The rear axle mounts with the standard U-brackets and bottom plate - also drilled out for a shock arm mount.






My original U-brackets snapped when I removed them, but I got new ones made up for only 19 bucks including bolts and washers.  The bargain of the restoration.  The only disappointment was that no one makes the original, flat-topped brackets as originally found on the car.  So I had to sacrifice a bit of originality in order to be able to drive the car.  maybe I'll find a set someday.




I hope some of this helped.

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Thanks for this perfect ijnformation, it is pretty much everything I need to answer my questions. I was interested in seeing you have both types of front springs, including one with the shock eliminator, I have never seen one of those except in the parts book. Some minor challenges remain for me, the underside of the flats for my axles have the nut/washer areas recessed into the casting (this area is flat on yours), making it a bit more problematic to place a shock mount. I will likely just place a spacer as necessary to raise that surrface sufficient to allow a shock plate. This explains why 2 of the front ubolts were longer than the other 2.


Regarding the shackles I showed initially, I understand figure 8 types these were standard for Chryslers of 1931, they used the so called "silent blocks" that year, designed to give a quiet ride, similar to the blocks shown in your front springs. The second type you show are similar to the shackle pin style used on my '31 Chevrolet and I see those shown diagramatically in the Chrysler parts book for other models, but not for CD8's


I spoke with some knowledgeable Mopar guys today and they suggested if the rear "silent blocks" are still tight and flexible, even if they are 85 years old, that I just leave them, and down the road if they become a problem, deal with it then. So I am thinking I will go that way, as all 6 blocks (4 Rear-rear, and 2 front-rear) are sound. I will clean up the cracked rubber washer/seals, sand blast and paint, and let the next guy worry about these 80 years from now!


Thanks again for your great help. Sites like this are so valuable to vintage car restorers. 

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You're correct, the Tryon shackles were also used by Chevrolet.  I know lots of Chrysler products shared parts and engineering, but your shackles are an obvious exception.  I love these architectural explorations as I always learn something I didn't know or find out I was dead wrong in my original assumption.  Let me know if I can help with anything else.

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