Shock absorber fluid

[JAYh]

I have a car here (small FWD sedan, ~2300 lbs) that came with ~100-120lb/in springs from the factory. I have a set of aftermarket coilovers which are 350lb/in front and 450lb/in rear.

So if I were to drain and refill the OEM shock absorbers, what kind of fluid should I put in to allow them to damp such high spring rates? Motor oil? Gear oil? Any suggestions?

(Note - I have NO budget at all dedicated to this car, as all the car fund is going into fixing up my Corolla. So buying new shocks is out of the question.)

- J

[h-bomb]

You'd have to use some form of hydraulic fluid since motor and tranmission oils will foam up...

[Tashko]

You could buy fluid from a motorcycle shop or use ATF. Do you have them apart already? I would assume you could plug some of the holes to increase the damping.

So you have coilovers, springs from coil overs or a coil-over kit to fit on your OEM shocks?

Are the OEM shocks dead? If you don't have the budget just save up until you can buy replacement shocks for the stock springs instead of messing around/hack jobbing for what I assume is a daily driver.

[JAYh]

The coilovers are just your standard aftermarket set with an adjustable spring sleeve. They fit over the factory struts. I want to firm up the mushy stock suspension on the cheap. This car will probably see a little autocross & lapping use while I've got the Corolla in bits.

Good idea on the motorcycle shop. Wouldn't plugging holes just cause the valving to blow out even faster?

(BTW the car is my old Eagle Summit which I'm putting back on the road. Probably the nicest $200 car I've ever bought.)

- J

[Greg F]

How do you plan to change the fluid?

[JAYh]

Uh oh - are they sealed units? The factory struts in my Corolla just come apart and you can put whatever fluid you want in. I was assuming these would be similar.

- J

[max attack]

Jay I think the inserts in your corolla srtut tubes are still sealed units,not 100% since I didn't look at them too hard as I pitched them over my should for better ones.(like 6 years ago in fact :) )
There is oil in the strut tube too cool the insert though.

[JAYh]

Not the front ones... I had them completely apart at one point. I had to pry a little rubber gromet out that sealed them off and damaged it in the process, but they did come apart.

Got your old Tokicos on there now though. ;)

- J

[Tony Kloosterma]

back in my old rally days we used to run a blend of stp and ford automatic transmission fluid in toyota struts.

If my memory services me correct it was a 50/50 mixture. But I can't remember the total amount. I am sure a service manula will tell you the amount of fluid


Tony

[rmicroys]

Depends on the shock I guess. I've rarely heard of automotive shocks being 'user serviceable' like a motorcycle front fork. I suppose that you can always get some uber thick motorcycle fork oil... no idea if that's really compatible with car shock oil though. I have had a few motorcycle shocks rebuilt, and because of underdamping characteristics, I did have the oil weight go up a couple steps and it made a huge difference to the damping characteristics. Maybe you need some of this:

http://www.hrpworld.com/client_images/ecommerce/client_39/products/505_1.jpg

[Slowpoke]

Realizing that money is an issue, if it's not a critical timeline part, you can ask Peter if he can take a crack at them. He rebuilds HotBits struts at his shop in Brampton for $75 CAD a corner.

http://www.motorsport-dist.com

[jay fieger]

did you settle on what to do on the shocks?
there are a number of hydraulic fluids that would work
I would use a shock specific fluid that would have the right heat range and anti-foaming characteristics
Penske makes a fluid but for the dollars I would use a QA-1 shock oil
you can get it from Grisdale's 1 800 561 1791
good luck
Jay

[JAYh]

Actually I decided not to bother with the car anymore. If I can't sell it it'll be my winter beater now.

But thanks for the reply - good info.

- J