Vintage Dirt Bike Q & A

These are neat shocks inside, with the surpise cartridge style inner steel cylinder.

What's the recommended oil quantity for these?

Thanks, Jon

AND, I found shock seals at the local hydraulic supply store. It's a 0.500" x 25mm x 3/8" poly seal. They were in stock!

Thanks,
Jon

Here is an old post on this forum from a guy named Jerry. I have dealt with him and he's a good guy:




Post subject: shocksPosted: Sat Feb 14, 2004 12:19 am

Your shocks are rebuildable. I sell seals for $12 a set but I need to know if they are the early 10mm shaft or later 12.5mm shaft. I recommend 5w oil nothing heavier seems to work. You can do it yourself they are not that complicated. The tricky part is filling them with oil. Too much and they lock up mid stroke, too little and they run out of dampening at the top of the stroke. Contact me at mailto:elsinorestuff@qwest.net if you want seals or if you want me to rebuild them for you.

Does anybody know the oil volume off the top of your head?

Thanks for lead though. I just don't want to bug the shop for information when I am building the shocks myself and I am not even buying the seals from him. He'd probably rather spend his time making money than telling me how to keep mine.

And, on those poly seals, the invoice says 1/2"x1"x3/8". I'll be darned if they don't happen to be just as close to the oem seals in size as I could hope for in 100% American measurements.

Sorry if I am really vague but if no one comes up with the exact amount...

Been at least 6 years but I seem to recall you can over fill the shock with oil and leave out the top seal/retainer and compress it to get the maximum amount of oil. Take out enough more so you can put the top seal and retainer in. They are kind of like the front forks in that the compression displaces oil such that you can overfill the shock to the point where they won't compress at all/bottom on oil. With the spring off it is pretty easy to check that you are getting full travel with full dampening.

Rick

Yes! Thank you, that ought to get me to where I need to be.

Yeeha!
Jon

the CR250 owner's manual recommends 145cc of ATF (thats right, automatic tranny fluid) for each fork after draining the original fluid. 165cc for a dry fill up.

Jon,

I don't know if you still need the quantity or not (I just saw this post).
The Showa shop manual specifies 125 cc of 5W Showa shock fluid, still
available at your local Honda dealer, after rebuild.

I used this amount when I rebuilt mine and it provides good damping
and rebound action.

dogger

_________________
1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R

do you know what oil wt. goes in the shocks on a 1980 cr250?

Those shocks use 5 wt Showa shock fluid as well. The manual doesn't specify an amount.

dogger

_________________
1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R