Topic: Is this exactly the same for a Cb350f? Changing fork oil.

[Dos]

[newday777]

The fork on the CB350F is of the same type with the drain plug so yes you can, but, if it hasn't been serviced properly and has sitting a long time with old oil in the forks it could be heavily gunked and will need more flushing than he showed or even talked about(I would highly suggest you put in 180cc of atf with drain plug bolt and washer installed  to flush- pump cycle the forks as he did to pump out the old oil, then drain that out before filling each tube with the proper amount of fork oil for the 350F.
And, possibly I would advise taking apart to fully clean out the old gunk and inspection of the internal parts for wear depending on how long it's been and how the condition of the forks and bike are in. There are wear bushings in the forks and the seals if they were leaking. The fork tubes wear through the chrome that needs to be inspected as well as the lower legs wear egg shaped internally, if not kept serviced yearly with fresh oil changes and being hammered in poor riding practices by people.....

[Deltarider]

I replace the fork oil maybe once every ten years. It always came out quite clean. Never needed to flush it, nor take it apart. The seals are still the same mounted in 1976. I suppose the harmonica rubbers protect real well.

[Bodi]

Yes, same.
Unless the removed fork oil is glittery from worn off metal, the fork is likely close to "good as new". They are very basic dampers anyway.
Assuming the old oil isn't black, glittery, or missing (this happens) a rinse with new ATF or fork oil (fill, pump, drain again) then a final fill is OK. Note that there is a fill volume spec for fluid change different from fill volume for dry after disassembly and service. Underfilling causes less damping, overfilling can blow the seals out if you hit a decent bump and bottom them on hydraulic lock.
Bad oil, water contaminated oil, or no oil forks need to be taken apart and inspected. Most parts are available at CMSNL, probably elsewhere too.
I believe there is a aftermarket piston valve assembly upgrade available, reputed to improve the damping. It would be difficult to make it much worse.

[Dos]

I got 15w belray fork oil and will be doing this soon!

Taking the springs out like he did doesn’t mean “disassembling” it right?
Manual gives two amounts and I should be putting in the smaller, just want to confirm

[BenelliSEI]

Correct on the smaller amount.

[Dos]

Correct on the smaller amount.

Thank you

[Bodi]

The forks oil is recommended as ATF, but Honda does not say which ATF of the many types available now to use... maybe things were simpler in the 70s?
However "classic" ATF as used in 70s transmissions is around SAE 5W viscosity. 15W may give you super stiff compression damping. I have used 15W and got that, I think I changed to 10W and it was OK but I may have mixed 10 and 5.
Please post what the 15W feels like to you, is it too stiff on bumps?

[Dos]

The forks oil is recommended as ATF, but Honda does not say which ATF of the many types available now to use... maybe things were simpler in the 70s?
However "classic" ATF as used in 70s transmissions is around SAE 5W viscosity. 15W may give you super stiff compression damping. I have used 15W and got that, I think I changed to 10W and it was OK but I may have mixed 10 and 5.
Please post what the 15W feels like to you, is it too stiff on bumps?

You got it, he's using 15w in his two cylinder and according to him it's in the middle and mine is a four cylinder weighing more so I thought with all of that it would be okay, I will check in and let you know!

[Dos]

OK so I took one off and on top of the spring there was this little nut that kept the spring attached to this rod it looks like I had to unscrew it to take the spring out but I was unable to screw it back in to hold the spring down I don’t know what that was used for or what to do so I just push down on the spring and tighten the top bolt

[Dos]

I can hear the spring moving around whenever I push down on the fork now.. how the hell do I get that bolt screw down onto the spring,
 the spring sticks up way too much for me to push it down to screw it down.

[zxshep]

I just took my 400f forks completely apart, cleaned everything, replaced both seals, and put it all back together.  Both my springs came to the top of the slider.  I simply pushed the bolt/cap down on top by hand which compressed the spring just enough and I twisted the slider to start it.  Then grabbed the box end and spun it around and snugged it up.  Once back in the tree I tightened the lower pinch bolt, gave the cap a quick snug, and tightened the top pinch bolt for each leg.

I believe the 350 and 400 forks are pretty much the same.  Are you sure the inner slider is fully extended?

[robvangulik]

OK so I took one off and on top of the spring there was this little nut that kept the spring attached to this rod it looks like I had to unscrew it to take the spring out but I was unable to screw it back in to hold the spring down I don’t know what that was used for or what to do so I just push down on the spring and tighten the top bolt

You did put the damping out of action.
With the top bolt off all you need to do is raise the lower leg, the rod will raise too, screw the nut on the rod and hey presto, damping is working again!

[Dos]

Phewf! I freaked there for a second. I dinged and stripped the bolts alittle but I got it back together. The 15w feels fine btw!