Fork Oil

[zanthor]

So I drained the fork oil last night and replaced it... The manual said 6.5oz each fork, I got just barely over 6oz out of both of them. The bike rides WAY different now!



As a side note, the wife wasn't overly pleased that I used her measuring cup... apparently it's now my measuring cup, and she gets a new one!

 

[grepper]

As a side note, the wife wasn't overly pleased that I used her measuring cup... apparently it's now my measuring cup, and she gets a new one!

Same here, I told her I'd wash it before I put it away, and she said never mind, just keep it. Guess she hadn't missed one of our strainers that I use for sifting blast media.

 

[raene]

What did you use for the fork oil? Wanting to do mine soon.

 

[zanthor]

I used 10W30, manual said to use that or tranny fluid. I also used 1oz of Marvels Mystery Oil in hopes of de-gunking some of the gunk. Plans are to drain/refill in about a month.

 

[raene]

Interesting, I thought it had to be Dexron ATF or fork oil Almost chickened out of doing mine after seeing some write-ups including removing most of the bar assembly to get to the air fittings. Yikes. Yours doesn't have that air fitting?

 

[dirtdigger]

10W fork oil is the all around oil. 10-30 will stiffen up the damping a little bit...good for hard riding or heavier loads. I dont like ATF, it can cause fork seal leaks if they were marginal to begin with. It also is on the thin side and can cause really soft suspension compared to a good fork oil. Motor oil can be used but I like actual fork oil because it was designed to be used as a damping fluid and resists foaming better and is more consistent then regular oil.

 

[zanthor]

Mine was easy, remove the caps with a crescent wrench, remove the drain plugs with a 10mm wrench, work the forks til the oil (sludge) stops coming out... I removed the springs and wiped them down, replaced and added the new oil. The caps were under slight spring tension even with the front wheel suspended, a bigger socket would have made getting the caps back on a lot easier.

 

[PWBII]

Folks, please be aware the viscosity of the oil you use makes no difference on how hard bumps are felt. The oil controls how fast the wheel returns to the lower position. As the oil is pulled through the holes in the damper assembly. Your spring is what makes the ride smooth or not. I use a heavier oil as my '76' is a full tourer now. Vetter fairing W/lowers & radios, Lockhart oil cooler, KG Engineering rack, sissy bar, trunk & saddlebags, with a Markland trailer hitch From a GL1100. So with this weight I need a slower recovery time on my front end (12" overstock). FYI I have '81' CB750 SS rear shocks on it for more travel in the back (13.5" long instead of 12", & adjustable dampening). You can get progressively wound springs for these bikes as well.

 

[PWBII]

Please feel feel to ask any CB750 SOHC questions you may have. I have had 30+ of these & still own 10. 2 chopped touring bikes, 1 dual on road off road, 1 cafe racer, 1 9' long chopper, 1 Jammer chopper & the rest are stock models. I just replaced the forks on the bike listed above.