Print Page - Shock fluid

Title: Shock fluid
Post by: enjenjo on February 15, 2006, 10:55:13 PM

What is used for shock fluid in Houdille shocks? I have one here that is empty, but I think it was drained, it shows no sign of leaks.

Title: Shock fluid
Post by: unklian on February 16, 2006, 04:02:19 AM

I'm sure people have used just about anything.

My first idea would be motorcycle fork oil.

Title: Re: Shock fluid
Post by: Bob Paulin on February 16, 2006, 07:45:29 AM

Quote from: "enjenjo"What is used for shock fluid in Houdille shocks? I have one here that is empty, but I think it was drained, it shows no sign of leaks.

Frank:

You really can use just about anything.

I have run racing shocks across my shock dyno containing everything from water to gear oil - and, pretty much everything in-between. There are some interesting results to be seen.

I'm in the process of collecting a number of different fluids in order to rank them comparitively with my own modified viscosity test. (Many oils/fluids today are ranked through different tests - SAE Crankcase, SAE Gear Oil, AGMA, ISO, etc. - for which there is no real equivalency comparison.)

What seems to work well for stock applications, however, is simple hydraulic jack oil.

You can also buy fork oil at a motorcycle shop in a couple of different viscosities.....

......a lot of ATV-ers/snowmobilers are now using ATF in their shocks (it's a little heavier viscosity - but I believe this is primarily due to an essential cheapness when it comes to paying $8.00-to-$15.00-plus per quart for shock oil).....

......and many oval-track race car shops now carry one or another brand of mineral and/or synthetic shock oil for re-buildable oval-track shocks.

B.P.

Title: Shock fluid
Post by: 48ford on February 17, 2006, 04:05:07 PM

Frank,
We just use 20# motor oil in the fork tubes on the honda bikes.
I'm to cheap to buy honda fork oil
Russ

Title: Shock fluid
Post by: enjenjo on February 17, 2006, 04:44:44 PM

Well, I think I'll drain the oil out of the good one, and refill them both with the same oil, so they work the same. The only concrete reference I have found for Houdille shocks suggests a 50/50 mix of hydraulic oil and STP.

Title: Shock fluid
Post by: Crosley.In.AZ on February 17, 2006, 11:59:06 PM

most of the stuff I have read is 10 - 15 wt oil

mixture of STP? never heard that. interested in how it would function

Title: Shock fluid
Post by: enjenjo on February 18, 2006, 12:03:20 AM

Tonight I located a source for the correct shock oil, so I ordered a qt. $4.

Title: Shock fluid
Post by: Crosley.In.AZ on February 18, 2006, 09:30:09 AM

Quote from: "enjenjo"Tonight I located a source for the correct shock oil, so I ordered a qt. $4.

is that a premix or straight weight oil?

Title: Shock fluid
Post by: enjenjo on February 18, 2006, 10:03:52 AM

It's not specified, my guess is straight weight.

Title: Shock fluid
Post by: Elmo Rodge on February 18, 2006, 10:42:03 AM

Frank, I think CW Moss carries it. Most any early FORD joint should. Wayno

Title: Shock fluid
Post by: Uncle Bob on February 18, 2006, 10:37:38 PM

Just a couple of comments to put suggestions in perspective even though you've already ordered oil.

Most hydraulic fluid is the approximate viscosity equivalent of an SAE 10.

ATF is the viscosity equivalent of a 5w20, has seal swell additive, detergent, and anit-wear additives.

The primary ingredient in STP and similars is a polymer (viscosity index improver) that is very much like that used in multi-grade oils, so mixing it with a straight grade essentially forms a multigrade.

Here's a table that compares various grading systems for similarities;
http://www.synlube.com/viscosit.htm#Viscosity%20Comparison%20Table Click the "Viscosity Comparison" link near the end of the "Viscosity" list.

Title: Shock fluid
Post by: enjenjo on February 19, 2006, 02:17:58 AM

I bookmarked that, some useful info there.

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Motorhead Message Central => Rodder's Roundtable => Topic started by: enjenjo on February 15, 2006, 10:55:13 PM