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lever arm damper oil question

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RobSelina

RobSelina

Jedi Warrior
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I can see the end of the project that's presently in the garage so I'm planning the next one which will be getting the midget back on the street. Right now I'm focusing on my plans for the suspension. I'm inclined to get Moss' 340lbs springs but would like to increase the front lever arm dampers effectiveness to an appropriate lever for the uprated springs. I realize they use 20W stock, and I'm wondering about using possibly 20W-50 synthetic.
I figure that would give me the best of both worlds since when cold the oil wouldn't be thicker than stock and would prevent damage to the damper but during sporty driving I'd have the benefit of higher viscosity oil and improved fade resistance from the synthetic.

Am I on the right track?

Thanks,
 
There are also uprated valves, I don't think multi-viscosity oils should be used in lever shocks. Some of the racers will be able to help, but if you want a vendor then consider Peter C. at Worldwide autoparts.
https://www.nosimport.com/
He can supply customized valves and give advice on damper ioil as well.
 
...I realize they use 20W stock, and I'm wondering about using possibly 20W-50 synthetic....

I'm not sure that the shocks use 20W oil...in any event, even if the *viscosity* is 20W, I'm sure it's not *motor* oil.
The oil used in these "shocks" (really, they are "dampers") is a light mineral-type oil used in hydraulic systems. The standard damper-oil, available from Moss and others, is a good way to start. Most folks just "top up" the damper-oil, but properly flushing them out and re-filling with fresh oil can make a nice difference. I'd do this and see how they are before any experimenting.
If you are game for experimenting, the race-valves mentioned can be useful.
You can also try various hydraulic oils or motorcycle fork-oil (many are not marked for viscosity, so it may be a guessing game). Some motorcycle fork-oil contains ingredients to reduce seal-leakage and might help an old set of leaking front dampers.
Years ago, I also tried ATF (auto trans) fluid, but I'm not sure it was a good idea.
Anyway, do not use motor oil in your lever-dampers.....though I'm not sure of the absolute technical reasons why you shouldn't do this, I know it will cause problems.
The 340# springs will be nice for a street car.
 
glad I asked /ubbthreads/images/graemlins/smile.gif

I'm going to get the master rebuild kit for the front suspension, the front springs, and I guess I'll start with fresh damper oil on all four corners and start from there. In the rear, I'm thinking I'll keep the existing springs but get poly bushings all around and call it a day.

I'm tempted to do an electric fan conversion and a weber or su at the same time, but we'll see what I can swing...
 
This subject has been discussed here in the past. My theory is that shocks are more like hydraulic brakes than engine components and that petroleum products (motor oils) are NOT good for the rubber seals in the shocks. They will prematurley fail, just like the brake seals, if they are contaminated with petroleum products.

As Aeronca65t has mentioned, many people on this board go to the local motorcycle shop and purchase fork oil.
 
that makes sense that it's a hydraulic/mineral oil given the rubber parts involved. We've got a good ATV shop here in town, I'll check with them for different fork oils since the owner really knows his stuff...
 
I have a 76 and I filled mine with that Power punch tranny fluid( SYRUP if you ask me.) And they were stiffer than Crap, but it ate through the seals in a year or so, but it handled awesome. LAne
 
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