ATF in forks? Suggestions?

[Jonzilla]

I have removed my old forks seals that were leaking on my still new to me 82 GS1100G. The big brown truck brought my new seals, new petcock, and tach cable today. I found only about half a pint of fluid in both forks combined! Blah! Anyway I'm ready to flush and refill my forks. The dealership is closed and I was thinking I'd try ATF this time since I've heard others have had decent luck with it plus it's cheaper.

Does it work well on big bikes like these? Or is it too lightweight? Thoughts? Experiences?

Thanks, in advance...

[salty_monk]

Use Fork Oil. 15w. ATF is fine for flushing them.

[bwringer]

ATF is a bit too light, but it won't hurt anything.

If you really wanna ride and don't mind doing the job over when you get real fork oil, go ahead.

Personally, I'd probably try half ATF, half 10W-30 motor oil. That's recommended in a few shop manuals for older bikes, and should be a bit closer to the correct viscosity.

Sometimes, you just gotta ride...

[Jonzilla]

speaking of which... Today I saw my tach work for the first time ever. Well, I have yet revv this thing over five grand prior to today! I'm used to lower revving engines and this thing SCREAMS!

So yeah, just gotta ride...

[Steve]

One problem with ATF is one that is not addressed on any ATF label.

What is the viscosity? Some are between 3-5w, others might be 5-7w, still others might be close to 10w, but you have no way of knowing.

Back "in the day", the service manuals suggested mixing ATF and 30w motor oil because that's what was available.

Nowadays, we have come a long way and have fork oil that does the job quite nicely and in known viscosities.

.

[bwringer]

One problem with ATF is one that is not addressed on any ATF label.

What is the viscosity? Some are between 3-5w, others might be 5-7w, still others might be close to 10w, but you have no way of knowing.

Back "in the day", the service manuals suggested mixing ATF and 30w motor oil because that's what was available.

Nowadays, we have come a long way and have fork oil that does the job quite nicely and in known viscosities.

.

Right. Real fork oil is far better.

But if there's no fork oil to be had, a substitute made from a mix of ATF and engine oil will let you go riding on a lovely sunny day and won't do any harm.

It's an old motorcycle, not a Martian Lander...

[Jonzilla]

It's an old motorcycle, not a Martian Lander...

Are you sure about that:

[trippivot]

lots of people use ATF 10 weight about. doesn't foam. do not mix with anything else. no engine oil !! you ll hate how the forks react when the foam happens


when these bikes were new they still used Whale blubber fat/oil base fluid cause it don't foam.

fork oil is best and you can mix 30 and 20 to get 25 or what ever combination you like.

[rustybronco]

lots of people use ATF 10 weight about. doesn't foam. do not mix with anything else. no engine oil!!...

Funny, I've been using a 50/50 mix of Dexron III and 20 Wt non detergent engine oil for about three years now...

[almarconi]

Jonzilla,

NEVER NEVER leave your little one near your bike by himself, don't turn your back on him or get distracted. Last year my two boys wanted to "help" put the bike away and knocked it off the center stand. Fortunately, there was a trash can sitting beside the bike that took the brunt of the damage. I turned my back on them for a split second. Scared me to death..I never seen those two kids run so fast in all my life. If that can had not have been there both of them could have been seriously injured.

[Jonzilla]

It appears he is in the side case but he is actually behind the case. Thanks for the warning though. I wouldn't let him pull or push on the bike or be near it without me right there of course!