Fork oil

So I am waiting for a rear motor mount,the bike is on the lift,I decided to change the fork oil.The book says to use 5 wt oil,but I am thinking about trying a heavier weight,I am thinking a 10wt.I know on the lighter bikes I've owned it could make a big difference in handling.But on a bike this heavy,is it going to have any noticeable effect?Any body have any experience they can share,good,bad,makes no difference?Thanks for reading this.

The 2 types of fork oil most commonly used are...Medium "Light" fork oil(replaces type B)and Medium(replaces type E)which is the heavier of the two and will result in a slightly stiffer damping action.Either will work.What will work BEST depends on riding habits and personal preference...Also when consulting a manual for the proper amount of replacement oil,there will be an amount for "wet" or "dry" forks which is referring to assembly procedures.If springs were removed and cleaned(or lower legs rebuilt,etc) before assembly use the "dry" amount.Otherwise use the amount indicated for "wet" application...hope this info helps...thanks,Junker.

gotta check the manual,but I do recall seeing a reference to "E" in some context.I do know it said 5wt,I am really just wondering if the oil weight will have a big effect,it seems the springs themselves would make for a more dramatic change.And if a 10wt would be too much,maybe the 7 wt would be better or if,in fact,I should go to the 20wt.I am sure it is mostly subjective,but just looking for opinions from guys that have experimented already.

Harley Davidson brand fork oil types/weights:
B Med/Light 5wt.
E Med 10wt.
SE 15wt.
SE Heavy 20wt.
I had a retail shop for several years and according to sale records the SE 15wt was the most popular choice.The 20wt oil is labeled "not recommended for street use" but I have a friend who is a service manager and claims it's what his techs use for all models.To make things even more complicated,different types/weights are commonly mixed in a 50/50 ratio as per rider preferences.And then of course there are others brands available in asst weights by Belray,Amsoil,,Lucas,etc...

My StreetGlide came with 10 weight oil in forks, and it rides rather stiff when the temp. falls below 65*. If you're riding in weather that is mostly above 70*, then go with the 10 weight. Heavier weight (20) oil makes for a harsh ride until the temps are in the 90's+.

If it wasn't so hard to change the fork oil on a FL with fairing, I'd change mine twice a year depending on the weather. On Dynas and Softails, it's a breeze.

just ordered new dampner kits for my 73 FL. already has new springs. so the 1st drain plug came right out, 2nd...she no budge. no way, no how. i saw that the new lower sets don't even have them. i guess the oil will have to get sucked out the top when changed. mine were full of sludge and goo, so much for having an indy do fork work.

so what's up with the "f" oil ? that's what i had recommended.

Try an impact driver to get that plug screw out.

the hex has been ruined...:rant:

A torx socket bit driven into the socket head of the screw works well as an extractor.But you will still need the impact wrench to bust it loose.Either that or you can make a tool to keep the damper assy from spinning out of a slotted piece of all thread.If you look down into the tube you'll see what I'm talking about.Applying a little anti-seize to the threads before assembly will make thing much easier next time around.Good luck...Junker.

you all echo my attempts...heat, torx bit etc. kinda makes me feel better.
i will end up making the holding tool. thanks for letting me jack this thread.

I run SE heavy fork oil in my wide glide and I love it. took out most of the front end dive and its cheaper than new springs.

You'd be a thousand times better off to just change to Progressive fork springs if you really want to improve the feel and handling of your bike's front end.

Probably so,but I'm not ready to put more money into it right now.I'm still waiting for the motor mounts to come in from Zanotti.I didnt expect it take so long to get them.The bike is on the lift with the rear mount removed,was hoping to replace them and change the fork oil and get to test ride before the ice age sets in this year,but it dont look so good now.

So I ended up using a 15 wt fork oil and I dont know if the improvement can be attributed to the heavier oil or just the fact that there is fresh oil,the old stuff was pretty black and likely been in there since '97,the ride is so much better now.So much tighter when taking fast corners.

A Big 10-4 on the Progressive Mono Tube for the front end, the best money I ever spent on my 03' Electra Glide Classic ( along with the Progressive rear shocks) !