The Stovebolt Site Forums The Shop Area Driveline leaf spring shackle seals

Has anyone else noticed that leaf spring shackle seals don't last very long?
Mine lasted just a few months before splitting open.


I wonder if there's a better type of rubber, or maybe I should trim them thinner so they aren't compressed so much?

This is the part:
[img]https://www.classicparts.com/images/74-092.jpg[/img]

They have gotten worse over the years. Offshore quality control may be to blame.
Denny Graham made some out of cork. I have wondered if making them out of leather would work. They don't do much work other than help to keep grit out of the pins. Leather would be more durable than the rubber or cork, especially being soaked with grease in that environment.

I like the leather idea and will try it out!
There's this foam tube too that would be good, assuming that silicone foam is compatible with grease.

https://www.mcmaster.com/1585n121

or maybe neoprene foam

https://www.mcmaster.com/2029n12

Buy Flexane 94, make a mold and create your own. They'll last a very long time.
https://www.amazon.com/Devcon-15250-Black-Flexane-Liquid/dp/B00065TLJK

Maybe the side wall of an old tire would work, punching them out with gasket punches. I’m just brainstorming!

The problem with tire rubber is its not the same as it used to be. I can remember using old tires on my car and they usually worked great until tread wore out. Now you get 5 years out of a set without them dry rotting or coming apart on you at highway speeds and your lucky. This type of rubber is also not happy with any kind of constant contact with petroleum products.

How about some large silicone orings?

Think I would agree with the leather idea.

On my 1954 , I used original NOS cork washers .

They fit the best & hold up well. I bought a whole box on ebay .

GM # 593705

https://i.postimg.cc/8zcFNrr6/Spring-Shackle-Cork-Gaskets-GM-NOS.jpg

&

https://i.postimg.cc/mgmsw-G7s/GM-593705.jpg

The old cork gaskets do show up on ebay once a year or so .


GM # 593705 cork gaskets superseded to GM # 3717880..........rubber washers .

https://i.postimg.cc/1zNfNhBR/s-l1600b.jpg


Whatever kind of rubber GM used they are 1,000% better than the worthless

made in china so called , rubber repro washers .


GM # 3717880 are available GM NOS .

Friesens Chevrolet
Sutton , Nebraska
phone : 402 - 773 - 5538

Friesens has (32 ) in stock


Dan's GM Obsolete
Chinook , Montana
phone : 406 - 357 - 2615

Dan's has ( 27 ) in stock


George
'54 3600

Thanks for the detailed and helpful reply as usual!
1000% sounds A-LOT better! It must add at least 20hp.

I ended up using leather, since I have some on hand and don't want to wait for shipping.
Perhaps only 5x better than the knockoff rubber ones

Leather was sandwiched between washers so I could drill a 1/2" hole, then the 1" outside was cut with bandsaw & scissors.
Two layers stack to ~1/4" thick when un-compressed. They softened up after a deluxe spa treatment submersed under oil for a few minutes in the microwave, but did not swell up much.

They seem to fit well.
pictures attached

I use the cutting punches. They work great for leather,gasket material, and cork.

I'm not going to worry about them on my newly installed bushings. I figure I'll be gone by the time they wear out and my wife will have sold my '50 3100 for what I told her I have in it!