Icon shock oil vs. Phillips 66 X/C Aviation Grade Hydraulic Fluid

Has anyone used this fluid in place of Icon shock oil? Is it ok to use in a rebuild for automotive shocks? I've read that some are using it to save some coin over Icon fluid which is over $50 per gal. The rebuild kit for my Icon coilovers shows the use of rubber O-rings and I've read that this fluid is not to be used with "natural rubber elastomers".

Here is the info on this fluid:

Phillips 66® X/C 5606H Aviation Hydraulic Fluid is a mineral oil-based fluid with a high viscosity index. It is ashless (zinc-free) and helps reduce wear for longer lasting components and reduced maintenance costs. The fluid is designed to meet the severe demands of aerospace and industrial applications. It is available in several container sizes and is priced low. This hydraulic fluid boasts excellent oxidation resistance and outstanding low temperature properties, making it ideal for long-haul flights and for use over a wide temperature range. Use the fluid in hydraulic pumps and motors to protect sensitive hydraulic system components against rust and corrosion. The premium hydraulic fluid is also resistant to excessive foam buildup that can cause poor or sluggish hydraulic system response.

Phillips 66® X/C 5606H Aviation Hydraulic Fluid meets the cleanliness requirements for "super clean" hydraulic fluid for use in modern aircraft hydraulic systems. This fluid is dyed a vibrant red color for identification and easy leak detection purposes. Phillips 66® X/C Aviation Hydraulic Fluids are recommended for use in non-pressurized systems operating between -54°C and 90°C (-65°F to 194°F), and in pressurized systems operating between -54°C and 135°C (-65°F to 275°F) at pressures up to 3,000 psi. It is available in your choice of container size and a manufacturer's certification may be added to any order for an additional charge. Order your Phillips 66® X/C MIL-PRF-5606 Aviation Hydraulic Fluid today to treat your system right.

Typical applications include:

• Aircraft and missile control systems, autopilots and shock absorbers
• Auto wreckers, boom trucks and electrical service equipment (cherry pickers) where all-weather performance is required
• Industrial robotics
• Hydraulic systems that require a "super clean" fluid for extended service life and reliability (X/C 5606H)

Note: Do not use these fluids in hydraulic systems with natural rubber elastomers.

 

I'd recommend sticking with a shock oil, they are pretty particular. King oil is pretty cheap and Fox oil is by far the best oil. Oil is responsible for lubricating everything inside your shocks ... you get what you pay for.

 

I would hate to go with a different brand oil not knowing if it has a different viscosity than what icon uses. Unfortunately Icon doesn't give any of that information.

 

Unless you've got gear oil in your shocks there's very little difference, highly doubt you'd notice the change in performance.

 

I'll have to look into Fox shock oil then. thanks.

 

From another post:

Shock Oil Weights & manufacturers.
ICON - 7wt
King (Shell) - 5wt
Fox Blue (F&L) (Std) - 5wt
Fox Red (F&L Ultra Extreme) (Race) - 7wt
Bilstein (F&L) - 7wt
Saw (Torco) - 7wt


King uses Shell Tellus 22 or 32, and it is not considered to be as good as the oil the rest of the brands use. Most race teams will swap it for Lucas or F&L. The Trophy Trucks use very expensive Maxima oil. You can use Mobil DTE 11M, about $80 for a 5 gallon pail

 

Thanks for that info. I did see these fluid weights after doing a little research.
I ended up going with Icon fluid only because I found it on Gotexhaust.com for $54.94 TOTAL
1 gallon jug

 

what would be the differences on a minute level? I mean, what does the thickness of the oil change in terms of shock performance?

 

When your wheel moves, oil is forced through orifices in the shock piston, that are restricted by tuning washers (shim stacks) to create the damping effect. A different weight of shock oil will create more or less damping effect, depending if it’s thinner or thicker.

The primary property of any shock oil, after weight, is thermal stability. You want an oil that stays the same close to the same thickness as it warms up.

 

right right, i mean, in this exact scenario, what would occur? As in, if you were to take an icon shock (which usually has 7w oil) and place 5w oil into it, precisely what changes would occur? Just curious, i like learning! haha Would thinner be more dampening cause it allows the oil to flow more? or the opposite?

 

I’m no expert on how big a change that is, but in general, a thinner oil will make the shock softer on small hits, and may make for a plusher ride, but the shock will bottom out easier as it will require less force to have the wheel travel upwards. For bigger hits, you may blow through all your travel and hit the bump stops.

Also, with a thinner oil, the wheel will recover quicker, meaning you may get more bounce-back (rebound) on larger hits. The oil damps in both directions.

 

interesting. Makes sense, thanks for that! Appreciate it. I will be rebuilding my icons soon and was just curious as the how each oil is different. Idk if i will stick with icon's oil or just check out a thinner oil to see what it's like.

 

Yeah. 5wt vs 7wt doesn’t sound like a big difference to me, but I have no point of reference.

 

if i may ask one more question, when do you know when to replace a bearing?

 

You jack up your truck, so the tires are off the ground, and try to move the wheel back and forth, in both vertical and horizontal directions. In the front, some play may come out of the suspension and steering, so you may need to eliminate those factors if they are also worn. In the rear, the wheel should be solid enough.

It’s best to compare one side to the other (PS to DS). Typically one bearing will go before the other, which can be a clue, if one wheel has more play.

 

Thank you!