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  1. #1
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    Fox 40 oil change

    For the 2011 40 RC2, Fox says to use 10wt. I have 7wt I used for my previous fork. Is there any reason I shouldn't use the 7wt? I know on older 40s they reccomend 7wt, wondering why the change and is there a reason I shouldn't use it. I got it apart and it definitely needed to be changed. Foam rings were nasty dirty. Barely any oil came out of the spring side, and the stuff that did was real bad. Which is weird because the fork nut on the spring side was on tight. The rebound fork nut was visibly loose, yet this side had much more oil and it was much cleaner. Which is even more weird because the last person that did this service was my LBS by a "certified Fox tech". Kinda pissed to be honest. There appears to not be any damage to the bushings, seals, and stanchions which is good.

  2. #2
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    I have used 7 wt all of the time for oil changes and never had a problem, after all it is just for lube not dampening.

    As for the oil levels your spring side seal must have been leaking more allowing more oil to travel out.
    The rebound side's oil will always look fresh and the spring side looks like crap, just due to the spring having minute bits flaking off ect it is nothing the other person did it is normal.

    Also which seals are you using and how often are you servicing, they only have 50 ml of oil in each leg fresh so you need to keep them serviced often to get the best out of them and not cause premature damage.

  3. #3
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    Sounds good thanks for the reply. I was more so pissed that the rebound fork nut was loose enough to see, and able to back it out by hand without the wrench. No apparent damage so no harm no foul.

  4. #4
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    10 wt oil would probually not leak out from the top of the seals. Maybe that's why changed? I need to change mine as well, forgot what weight to use. Glad I saw this post!
    The guy yo' momma "act" like she don't know!

  5. #5
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    The Fox website has a very useful and easy to use tech section. They reccomend their 10wt green for lube oil and their 10wt red for damper oil. My damper oil is probably okay, they say to do the damper service every 100hrs and lube oil every 30. I was way past the 30hr mark, but still a ways off 100

  6. #6
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    As far as lubrication goes you could use pretty much much any oil weight you'd want without damaging the internals of the fork... Not any type of lubing oil though , you should avoid motor or transmission oil .Some says its better to have something lighter so it "splashes" around the interior of the fork more easily when the fork is cycling , others says its better to use heavy-ier stuff so it "stays" where it should be better...

    With all that said, GET THE FOX GREEN stuff.I HIGHLY recommend it .Ive been servicing my own suspension for well over a decade now, Ive experimented with different oil in the past, some made subtle differences but nothing comes even close to the Fox Green 10wt.Its much more slippy , doesnt foam and last quite a bit longer.Get you LBS to order it for you if your having trouble finding it.Its a bit more pricey but SOOOOOO worth it.

    You should never wait until the oil turns mucky/grayiiish before servicing the lowers, its BAD for the bushings and wears out your seals quicker.Its SOOOOOOOOOoooooooo easy to do , I see no reason why one would need to wait and bring it in to a shop, like seriously , a child could do this in no time.Fox's site is your friend, use it

  7. #7
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    Can someone shed some light on what the bushings and internals of the lowers should like like? I.e. what should I be looking for that would indicate damage or wear? I didn't see anything I regarded as being too worn or damaged, but I am new to suspension servicing. The amount of oil and color of it that came out of the spring side has me skeptical. It appeared as if the oil on the spring side was mostly coming out of the shaft and stanchion itself, rather than the lowers. I saw some small holes at the bottom of the stanchion shaft which I would assume are ports that the lubricating oil passes through to lube other areas inside the shaft and stanchion. Is this correct? Is the oil coming from the shaft and stanchion to be expected?

  8. #8
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    check the bushings for cracks you will see a line in the middle of the white bushing part, other then that you can only wait until you get slop in the bushings which will be caused from wear. I had no slop after 3 seasons and only found a crack( which caused me to buy new lowers) I found the crack as a line in started to show in the anodizing so I took the fork apart and found it.

    Always flush out the old oil and residue on the bushings with rubbing alcohol and let dry after to make sure there is nothing that is going to cause damage

    You will have to let the spring side drip for longer and should also flush it out as the spring will hold oil as well as the collar which the spring sits on.

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