Fox fork oil instructions from Enduro fork seals?

Have you checked with Fox, whether using motor oil would void the fork warranty?

I've been using synth motor oil for several years in the lowers of my Psylo Race, Minute 3, and Van36 and all are working smooth, no issues.

It is frustrating that RS and Fox don't recommend motor oil, maybe because they don't sell motor oil and want people to use their fork oil instead, because as pointed out, for lubricating the lowers/seals/wipers/bushings, (synth) motor oil is as good or better than fork oil.

On the non-damper side, yes, you can use motor oil since it's only lubricating the bushings. On the damper side you need to use the proper weight suspension oil.

The problem is motor oil is much too heavy a modern fork's damping system. If the damper shares oil with the bushing lubricating oil, then you must use suspension oil. There's nothing special about Fox's and Rock Shox's oil, just go to your local motorcycle store and buy the appropriate fork oil there. You'll end up paying $8 to $12 for a quart.

I use 10w30 synthetic oil in the non-damping side of fork. Shock oil from the motorcycle shop in the damping side. Coming from motorcycles, this seemed normal. Is less expensive also. lol

Fender Roads said:

"32) Inject 15cc of multi-viscosity fully
synthetic motor oil into the bottom of
the TALAS side fork leg.
The multi-viscosity, fully synthetic
motor oil we chose to use is made by
Amzoil®. Any other reputable brand is
acceptable. Note that Fox recommends
damper oil. Damper oil is OK, but does
not stick to the parts as well as the
mulit-viscosity synthetic motor oil."

Yay or nay.... should I stick with the regular Fox suspension oil (Torco RSF) or does anyone care to comment about the info from Enduro?

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First off I believe you meant Amsoil and they make very very nice oils (only thing I use in my car engine/trans) and were the first in the synthetic world www.amsoil.com you can check their history and all the independant lab test.

Second the only thing I have heard that may an issue but posibly not with the poly enduro seals is motor oils have seal swelling agents in them and that is not really what you want on your fork seals as it could possibly cause more friction.

Oil

I actually have the Amsoil shown in their picture (TDI Jetta).

The text I copied was straight from their site. I thought it would be too heavy as well.. that is why I posted.

I'll probably just get some of the fork fluid/oil from the local moto shop. They carry a nice selection, they usually have several, including Torco, GS, silkolene and a few others.

Jesse Hill said:

First off I believe you meant Amsoil and they make very very nice oils (only thing I use in my car engine/trans) and were the first in the synthetic world www.amsoil.com you can check their history and all the independant lab test.

Second the only thing I have heard that may an issue but posibly not with the poly enduro seals is motor oils have seal swelling agents in them and that is not really what you want on your fork seals as it could possibly cause more friction.

Click to expand...

We've had no issues with seal swellers in synthetic motor oils. Every once in a while somebody gets the wild idea to run transmission fluid in his fork and we've had some seal issues with that...

I tend to agree with Chris on this one. I recently swapped to motor oil on my 36 and found the operation much smoother than before. Time will tell how long it lasts, however. The one thing I am disturbed about, WRT the FIT forks is that there's such a small bath of oil, especially on the TALAS side (only 15cc). That 15cc is small and can barely coat the inside parts (as evidenced by trying to get the oil out after it has coated the inside), and through normal operation, it gradually can drop. A small loss can make a big difference.

Anyhow, I used 5w-40 semi-synth (full synth is stupid expensive out here!) motor oil and it feels so much better than fresh shock oil.