fork oil change

[ailll1]

i want to change the oil in my 85 250sx forks
first i think it will probably be almost a refill cuz right they feels like theres not much fluid in them, really soft
so i want to know if i need to take them apart(i guess not)
do i just need to drain it from the lower plug and than lifting the front wheel to refill it with the exact quantity by the bottom or by the top.
ill also put up new seals (im guessing if theres no fluid in them they leak?)
is ATF a good oil to put in as its recommended in the service manual?

thanks guys for all tips

[ailll1]

any hint or procedure please?

[johnny's X]

If you just want to rechange your fluid then drain and add. Forks are not hard to rebuild. If you are going as far as putting new seals in you might as well take them apart and give everything a good cleaning. You can have this done in a couple hours easy. Yes tranny fluid works well. Some people say only use fork oil but I have good luck with trans fluid.

[Escanabajosh]

i'd read the manual, there on this site somewhere. i did my 86sx last fall, super easy to do.

[Grizzlypeg]

It was tedious, but I measured the ATF using a large veterinary syringe. The manual gives a pretty narrow margin for how many cc's you are supposed to put in. Hard to believe its that critical. I just tore mine down and changed the seals. Nasty contents came out, one had an emulsion with water, the other the remaining oil was like wheel bearing grease mixed with graphite. I washed every part in solvent, took me a good afternoon to do it at my slow pace.

If you are not prepared to tear them down and change the seal, check how clean the contents is that comes out. You might want to flush it out with solvent and let them dry overnight.

[ailll1]

ill drain them monday as ill be at my grand-parents house until sunday
ill check how's the oil looking, maybe ill just refill them
i dont want to screw with them much and dont be able to ride for the long weekend
and they are still rideable just need to slow down more when approaching bumps
plus its super sunny and hot out here (25 celcius,almost 80 for you americans)

[3wheelmecca]

ATF+4 works the best in those, I run it in all my forked vehicles. Just my $.02 though.

[ailll1]

didnt work as well as i thought
theres was no oil in each in them
i refilled them and i found out why
both sliders were cracked but only one leaked
any of you guys ever tried to repair those?
i dont want to buy new ones(i dont want to spend to much in it, i just want to be able to ride, not looking for perfection)

[Grizzlypeg]

Cracked sliders? That sounds like serious structural failure. If it were me, I'd consider them junk. You can't be having a front fork failure while you are driving.

[Red Rider]

Any pics of the cracks? If the cracks are on the aluminum portion of the foks (where the wheel mounts) they can probably be welded & repaired. But if the cracks are on the chromed slider portion, then you're better off getting some new sliders.

[ailll1]

yeah they are on the aluminium part of the fork
about 1-2 inch long
how hard would it be to weld on aluminium?
any tricks or special procedure?
i dont have any welding machine but some of my buddies do

[Grizzlypeg]

Best technique for welding aluminum is a tig welder. Any kind of welding, especially aluminum, requires someone with a lot of skill to have it turn out right. I would look for a good pair of used forks. Someone must be parting one out in your area.

[Thorpe]

As much oil as has leaked through those forks, they will weld like crapola... I have welded tons of aluminum, and dirty oil aluminum sucks! I would start shopping for a decent set of used forks...

[tundrawolf]

My forks are awful stiff. I have an 82 Honda ATC 110. I poured a bunch of oil in the handlebars but it didn't do much. It just sort of dribbled out. I also zip tied a shock absorber from a toyota pickup on the back to hopefully give me a little more travel in the rear and a more plush ride. It didn't really do much either.

[Dirtcrasher]

ATF is roughly 10wt fork oil. The SX has a very soft front end being it a trail/working type trike.

The SX is famous for having the wrong front tire that wears AWAY the aluminum, but cracked?? I've never even seen that and there must be a reason for it.

The problem is, you probably only have a "home oven" but what you can do is take them apart (read the free manual online that guys here offer) and then clean them spotless. It's hard to get that lower leg clean down low, I have a large and long bristle brush I use but many times in the past I used gas and some steel wool on a long piece of 3/8,1/2" threaded rod.......

So, without stinking up the oven, once it's cleaned spotless and then clean it with hot soapy water; Then you can use a propane torch on that area to try and get some of the old oil trapped in that crack. I'd just keep heating it and cleaning it, the heat drives out the contaminants. Then go find someone with a nice TIG welder who knows what he's doing.

This is an SX..... You can upgrade to a 200X front end which is nice or if you have no welder available, this is one case that JB weld could be used. It's already been run without oil, so if the JB weld fails, it can't be any worse than you have now..... At the very least, the 250SX needs some 1.250 long spacers on top of the top fork spring. With that and some 20 wt oil, it will be a bit stiffer. They are super soft in stock form! Or, grab a whole 200X front end 83-87 and rebuild those forks; Some new steering stops will have to be fabricated up but it's a nice improvement for the 250SX. Your forks ran dry, had some type of violent damage so who knows whats up with them?? The teflon type coating on the inner bushings/guides may be junk at this point anyhow.

A 200X front end swap gives you better front suspension, a skinny front tire and a front disc brake. It's my opinion that EVERY SX ought to have an upgraded front end......

If anyone wants steering stops fabricated or spacers made to center the wheel, I can make them up for a swap like this if you go that route............