whats the difference between Hydraulic Oil, ATF, Power Steering Fluid, and Fork Oil... Adatives, that's about it... yea there might be a few chemical break down differances between them all as well.. but they all are 10 wt and they all do similar stuff.

 

Honda states in their owners book to use trans fluid in the older wings...

DT

 

I used hydralic jack oil in mine. It states on the container that it can be used for fork oil.

 

Thanks Folks, thats about what I thought... I got to wondering after seeing a bottle of Bel-Ray (I think) at the Honda shop here for $16.95, probably about 1/2 that at the Kawasaki shop in Tullahoma...
The Honda shop here makes the Hardly shops in larger cities seem like china-marts, hard to believe, but they don't sell much...
Have a good one...Old Dog...

 

Again, Honda dealers seem to have a well deserved reputation for ripping off customers. Granted, all dealers do, but Honda seems to come up a lot more often. I have rarely ever changed the fork oil in any of my many bikes. I have had a couple of bikes where the fork seals leaked so badly that I put 140W gear oil in the forks, that didn't leak out, but the suspension was pretty stiff. They were beater bikes, and IMO, not worth replacing the fork seals on.

Transmission fluid should work fine as general purpose fork oil. Some riders like to "tune" their front suspension by using different weights of oil, until they get it just right. Other than cranking the preload on the rear shocks all the way up, I just get on and ride. Jerry.

 

This was hashed out awhile back, but the overall answer I gave was that ATF can be used in the forks as it is basicly the same oil as commercial fork oil.

The difference here is , as mentioned, additives, and that ATF , or even other oils labeled as "Fork Oil" for that matter, do not conform to any specific testing critiria...meaning that Yamaha 10 weight fork oil may not be the same weight as Bel Ray 10 w fork oil.

Thus, you have no real idea how the suspension will act with a given oil until you use it. That is why most times you will see it suggested to use 15w Bel Ray oil here in the forks, because that is what others have tried and found to work best for them.

"Fork Oil" usually has anti-foaming agents in it, which is a good thing as you do not want air in suspension componet oil. But the main difference is having a better idea how the oil will perform in your forks...as contrary to what was mentioned all ATF is not 10w oil...it may be close to 10w, like 14 or 9. And real small changes in oil weight can be felt in your suspension.

So as Jerry said, if you ain't looking to make the parts work better, ATF will work...but if you want to "tune" the suspension to make the bike handle or feel better, stick with fork oils from one specific maker.


KM

 

I agree fork oil weight has a lot to do with your ride tuning and getting it right means a lot, too thin and it will be sloppy, too thick and the tire will not return to ground quick enough and can cause a serious slide in a turn by no or little contact with the low spots, very important that you get it right...
I agree with what KM said about sticking with the same brand, it will let you do a better or easier tune as the weights will be different from brand to brand...
I was mostly thinking how they just more or less bottle up, label it and rip us off...lol...
Have a good one...Old Dog...

 

My FJ1200 manual says fork oil, atf, even 10w-30. I think its worth going thru the forks anytime the seals leak. Amazing how much sludge builds up in the bottom of the sliders. I don't like rebuilding forks, but everytime I do it, the action is noticeably better. FWIW I always use Bell 10w fork oil.

 

I don't have any leaks, but plan on replacing the +/- 5 wt. with +/-10 wt., and adding Shrader valves so I can add up to about 5 PSI of air, I have already changed the springs to progressive...
By my feel before, that should fix things up pretty good (I hope)...lol...
Have a good one...Old Dog...

 

First, I would not buy your fork oil from a rip off dealer if you intend to use real fork oil. You can find name brands at motorcycle accessory stores (I have a Cycle Gear nearby), or from an online source MUCH cheaper than from a dealer. I usually get all my maintenance supplies either from Cycle Gear, or if I can wait a few days, I can get them even cheaper from Dennis Kirk, with free shipping and no tax. If your front end feels to mushy, I would go with the 15W oil.

One thing I would not do is put air in the forks. If your fork seals are ok now, air can blow them out. My rear shocks have Shrader valves on them, but the manual calls for 0 psi for normal operation. I have 44,000 miles on my bike, it still has the original fork oil in it, still feels fine, seals do not leak. Also has original rear shocks, which still work fine. I do not expect to ever have to do any maintenance or repairs to either, my first Vulcan 750, a '93 bought new, had over 80,000 miles on it when I stupidly traded it for an '01 KLR650, it would probably have lasted over 100,000 miles. It also still had the original rear shocks, and the original fluid in the forks, and the seals did not leak. But I put that 80,000 miles on it in less than 8 years. It was on it's fifth set of tires. I seem to have good luck with tire mileage. I keep them inflated to max pressure, or just a little bit over. Jerry.

 

Atf...

Ive been using ATF in my street bike forks since 1975...(the GM type...Dexron)...ATF actually makes seals swell a bit and seals better (think...ATrans's have rubber seals...)...the new synthetics are 10W, btw...and the old GM was as well...the Ford was around 14W since Fords leak, lol...
Ive also used Marvel Mystery...less than most "fork oils", but more than ATF...(MMO is really just ATF imo).....

 

Once again, interesting information from all of you. My main fork seals don't leak but the dust seals are dry rotted so I had planned on doing everything in spring but what are your thoughts on just pulling the forks to do the dust seals and leaving the rest well enough alone if they'e still playing nice together?
I like to leave things alone when they're working well, and since I have the spline lube and some other maintenance to do, thought maybe it was worth asking you guys (blanket word, ladies always included) on here and maybe lessen the down time. Plus it might make sense to spend some $ on progressive if/when I take everything apart.
As always, your opinions and knowledge are priceless and appreciated.

 

Once again, interesting information from all of you. My main fork seals don't leak but the dust seals are dry rotted so I had planned on doing everything in spring but what are your thoughts on just pulling the forks to do the dust seals and leaving the rest well enough alone if they'e still playing nice together?
I like to leave things alone when they're working well, and since I have the spline lube and some other maintenance to do, thought maybe it was worth asking you guys (blanket word, ladies always included) on here and maybe lessen the down time. Plus it might make sense to spend some $ on progressive if/when I take everything apart.
As always, your opinions and knowledge are priceless and appreciated.

My seals are in the same shape as yours, Dave. I have related my thinking on replacing the seals vs. a complete tear-down, cleaning and rebuild of the fork tubes in another thread recently, but will reiterate a bit of it here anyway.

I might be tempted to just do a "quick and dirty" oil and dust seal change but for a couple of reasons.
Firstly I have no records of any service my Vulcan has received before I got her.

Second, the fork tubes were twisted about 30* or so off center in the head clamps in my accident 3 years ago. They do not appear to be damaged or bent in any way, and I was able to loosen the clamp bolts and twist the tubes back straight as measured visually with my *Mach1* eyeballs. :smiley_th

I`m a sort of curious fella, and like to know how things are put together and how they work. I figure it is worth my time to follow Ron`s directions for a full dismantling, cleaning and reassembly just to make sure nothing is damaged inside the tubes, and that the oil is not contaminated, and is filled to the proper level. :smiley_th

 

Dave, I kinda go along with your thoughts, "if it aint broke, don't fix it"...
But on the other hand, if it looks like it's about to go bad or it's lasted a lot longer than it should, maybe you should replace the seals while the forks are off...
Didn't help much did I. ...???...lol...
Sorry, have a good one...Old Dog...

 

Lol, you helped. It's good to know that I'm not the only one who goes back and forth. Thanks OD. Facebook gut nuthin' on this site man! . Coffee, vn750.com and then if there's time before work, facebook, ha ha. Enjoy the day.

 

Fork Oil

I really like this site. Just ask the question and there is so much knowledge available. Most things have been tried and there is always an answer. This makes owning a vn750 an interesting experience. Thanks Guys

Mcneuby :beerchug:

 

Your fork seals can go another 15-30,000 miles and not leak....or leak tomorrow. If you are fine doing the work, replace them, your springs and oil. Me? I'd only replace them if they start leaking. (not sure how many miles years you have on them btw)

Its just kind of a gamble... if you do replace them you can feel comfortable they will go for awhile with out need of care.....

 

Thanks again guys. Gordon you're right about knowing that everything's clean and in good shape in there. I'm curious too and love to see "What makes it go" so I'll consider the gain of knowledge here. KM, I got it with 11k on it and I'm at 15k now so my guess is that they have never been touched? Ha ha, also there's Murphy's law that makes it highly probable that I'll do the dust seals and that same season she'll spring a leak in the main seals . Maybe I'll plan for the spline lube and the other things in spring 2012 and let the sleeping fork dogs lay until the following. But thanks again for sharing your knowledge guys.
Yeah Mcneuby, if I found such decent and knowledgeable people willing to share their knowledge and help others in my workplace, I'd like my job even better. Great people on here, no doubt.
Take care :beerchug:

BTW Gordon, good job using your *mach1* eyeballs ha ha. Very glad the accident wasn't worse for you also.

 

I too am dreading replacing a fork seal. Did in once on my old Yamaha 400, then again on the Vulcan (as a set, of course). Got my next Vulcan, and switched out the whole front end since the dead one had new fork seals and tires, but the two years of sitting seems to have caused a leak. If ATF or a heavier oil has a chance of curing my woes and KM hasn't shot it down, I'd say its definitely worth a go, especially since I wouldn't mind stiffening her up a bit.

Another fork trick I have heard of is sliding a piece of 35mm film down between the upper and lower tubes. The crud gets stuck in the little square holes and comes out when you pull the film back up.

Also, FWIW, the best way to get the most life out of your fork seals is to regularly clean the forks with a soft cloth, especially when pollen is in the air. A little penetrating oil here and there might help keep the dust covers supple too.

Last word... if you do replace the seals, don't forget Kawasaki special part number 3904872304987, the broom/plunger handle to keep the air cylinder from spinning when you take out the lower allen bolt. (That's how I found VN750.com!)

 

I just wanted to say that whatever you are going to do to your forks, be it new seals or just new oil, you should really add to the list installing a set of Progressive fork springs if it had not been done yet. Best bang for the buck item you can add to your bike that actually makes it better. Number two on my list of mods that improve the way the bike works....right after an AGM battery.

And if you are an aggressive rider like me, a fork brace will make a good addition too.

 

Thanks KM. I was thinking about progressive springs as well as the superbrace. I'd like a more solid front end in the curves. Don't know if I'm as agressive as you but I seem to use all the tread area on my tires so I'm sure I'd benefit from it. Plus a stamp of approval from you and others here gives the idea more weight. I'd also like to lower the butt just a little. Maybe just an inch or two. Probably have to go with a shorter shock since the relocation plate seems to lower it too much (i like using my center stand for service / maint.).