changing fork oil on SEi?


Information and questions on GL1200 Goldwings (1984-1987)
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Rusty Bike
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changing fork oil on SEi?

Postby Rusty Bike » Sat Jun 11, 2016 12:50 pm



Can one change the fork oil without total removal of the forks? I seem to remember that the oil could be drained by removing first the front wheel then the bottom bolt. Pumping the lower slider up and down would pump out the oil. You could then remove the top cap easily because the fork spring was not under preload ( fork would be over extended). Next install bottom bolt and refill fork with proper oil. Last fight the top cap back on.
This procedure is going back 30 years for me. It seems like that is how I did it on my Yamaha 750 special. Will this work on the Wing? Thanks...Rusty



Rusty Bike
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Motorcycle: 86 GL1200 SEi, 78 Yamaha XS750SE, 86 Honda XL125, 4.5 HP belt drive Minibike my dad built, foot clutch!

Re: changing fork oil on SEi?

Postby Rusty Bike » Sun Jun 12, 2016 11:46 am

OK, it really bugs me that one has to tear the front end down to change fork oil. I am thinking about drilling and taping a small hole in the bottom rear of each slider, then plugging the the hole with a suitable bolt and seal. Do the same to the fork cap. Now one could pull the plugs, drain the oil, reinstall the bottom plugs and fill forks from the top without releasing the fork springs. Reinstall the top plugs and GO! If you did this yearly the entire front suspension would hold up better. You also save a ton of time and effort. Well any thoughts on this?

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geraldm
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Re: changing fork oil on SEi?

Postby geraldm » Wed Jun 15, 2016 5:36 pm

if you remove the antidive mec. ((providing it is the same as the GL)) on the bottom of the forks the oil will drain ,, there is one bolt that needs to be removed not all but can't remember which one . would be one of the bottom ones of course . no gaskets there on the anti dive ..,just an o ring .. also for filling i drilled a hole in the top tube cap tapped it to 1/8 npt and made a wire that reached down inside and with the tubes full ( 11 oz. on gl ) made a dipstick with a mark at full level ,,so now I can check the level with the dipstick and add through the same hole if low . hope this helps

flash1942
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Re: changing fork oil on SEi?

Postby flash1942 » Thu Jun 16, 2016 8:48 am

I think there is a drain bolt on the back of the legs.

Rusty Bike
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Re: changing fork oil on SEi?

Postby Rusty Bike » Thu Jun 16, 2016 7:34 pm

Great info thanks. I have my forks on the bench right now. I'll check that TRAC bolt layout. I was wondering if removing something there would drain the forks. The taped top cap is going to happen. I wonder if I can find SS pipe plugs.
By the looks of the old fork oil, it may have never been changed in 44,000 miles! Gray/black sludge, what a mess! I see the chrome is worn from the bottom 2" of the fork on one side. I have not yet checked for play when in the slider. Waiting for bottom bushings to come in.
I did go for the Progressive springs. Should get front end back on this weekend. OH Boy...

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geraldm
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Re: changing fork oil on SEi?

Postby geraldm » Thu Jun 16, 2016 10:26 pm

yea I went for the ss plugs also , was in the winter when I did this mod so I just order a pkg. from japan and waited but there must be a place that sells fittings near you . even a bolt supply company should have .

Rusty Bike
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Re: changing fork oil on SEi?

Postby Rusty Bike » Sat Jun 18, 2016 9:25 am

Well, it appears to me that the front forks needs more then more then a plug in the top cap. I have excessive play between the fork leg, (with new bushings installed) and the slider. Bike has 44,000 miles. I do not have the means to measure the slider bore but seat of the pants experience tells me that the slop found, is not good! The lower bushing will move laterally when positioned in the middle of it's travel. This play is gone at the bottom of the stroke and at the top or higher. Fork slider is loose on fork! No doubt the result of lack of maintenance. That gray sludge that drained from the forks is what is left of my slider inner bore! I can not think of a fix for this type of wear.
Does anyone know of a fix for this or, have some NOS sliders? Crap!
Last edited by Rusty Bike on Sat Jun 18, 2016 10:19 am, edited 2 times in total.

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geraldm
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Re: changing fork oil on SEi?

Postby geraldm » Sat Jun 18, 2016 9:59 am

Yea mine was about 1 Oz. Of the grey crap in each fork. It was just working on the springs. Not saying it is OK but mine was very loose before assembly. After installing everything and seals it seemed to tighten up. And works fine. Make sure you have neck torqued proper when finished or you will end up with the wobble.

Rusty Bike
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Re: changing fork oil on SEi?

Postby Rusty Bike » Sat Jun 18, 2016 10:12 am

Buy "neck" do you mean steering head bearings? I did not remove the triple tree.
Last edited by Rusty Bike on Sat Jun 18, 2016 10:20 am, edited 1 time in total.

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geraldm
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Re: changing fork oil on SEi?

Postby geraldm » Sat Jun 18, 2016 10:19 am

Yes. Where the neck goes through the frame. That big nut needs to be torqued can't remember how much.

Rusty Bike
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Re: changing fork oil on SEi?

Postby Rusty Bike » Sat Jun 18, 2016 11:31 am

My bike does have the typical "Head Shake" issue. I feel that worn lower legs would be a huge factor in the cause of this phenomenon. If the lower legs move out of parallel alignment due to sloppy bores, the bike is going to turn! This slop may set up an oscillation, the severity of which is directly proportional to the distance the fork can move in the slider.
Hmm, I think I'll take the sliders to the local speed shop and see if they can mic the slider bores. This is getting interesting! :roll:

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geraldm
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Re: changing fork oil on SEi?

Postby geraldm » Sat Jun 18, 2016 7:16 pm

Not saying the bushings arent worn and maybe do need replaced but I think you will find unless you torque the neck brg. proper you will get the shake wobble and also ,,, it;s hard to explain but you get the feeling that you can feel every stone amplified you drive over on the road and also tends to jump around a fair bit on small ridges :o that really should not be felt ..

Rusty Bike
Posts: 270
Joined: Sun Feb 28, 2016 1:55 pm
Location: New castle, PA
Motorcycle: 86 GL1200 SEi, 78 Yamaha XS750SE, 86 Honda XL125, 4.5 HP belt drive Minibike my dad built, foot clutch!

Re: changing fork oil on SEi?

Postby Rusty Bike » Sun Jun 19, 2016 11:44 am

Well, the speed shop is closed on weekends so i did some further shade tree tests. Clamped the fork to the bench the put a pivot point in the slider where the seal goes. Put the fork in the slider and rocked it on the pivot. There is play in the middle of the travel area but this slop is not as bad as I had first discovered. I'm going to call it "not too bad" :| . I went ahead and assembled the forks with the new Progressive springs. I did install a 1/4" PVC spacer under the fork cap, figured since I'm 275 Lbs, that should help hold the load. Also drilled and taped the fork cap to facilitate future fork oil changes. And the beat goes on...

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geraldm
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Re: changing fork oil on SEi?

Postby geraldm » Sun Jun 19, 2016 12:05 pm

Even if they are worn a tad IMO there is little to no danger. I'm sure your tired of buying parts for now but unless good the neck brg. Are very important in the front end performance. Nothing against and brg. Manufacturer but it seems that All Balls have a very good brg. Assemblies..as the rollers are a tad smaller but there are more of them making for a superior brg. That is for any brg. Front Wheel rear wheel etc.




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