Front Suspension Question


Information and questions on GL1500 Goldwings (1988-2000)
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Nattex
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Joined: Mon Apr 17, 2017 3:16 pm
Location: La Porte, TX
Motorcycle: 1994 Goldwing GL1500 SE

Front Suspension Question

Post by Nattex »



I have a new to me 1994 GL1500 with 110,000 miles. I'm in the process of working out some bugs with it. The first being a front suspension that doesn't quite seem right. It is okay as long as I'm on a perfectly smooth road. But as soon as the road gets a liitle rough the front end seems very loose and I feel every little irregularity. I have tried running everywhere from 0-6 psi in the fork and it doesnt make much of a difference. I also noticed some oil under the cap when filling with air. Seems to me that would indicate a seal issue but they do hold air pressure? I think my first thing to try will be to go to a Progressive spring and rebuild the forks. Does this sound like a good first place to start?


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MikeB
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Re: Front Suspension Question

Post by MikeB »

I suggest removing the fork tubes, taking them apart, cleaning out the old oil, maybe even replacing the seals and bushings while it is apart and installing the Progressive Springs.
Air is not recommended when using the Progressive Springs.

There is no telling how long ago the fork oil was replaced.
MikeB
1998 - GL1500 w/184,500 miles ~ 2017 - GL1800 w/13000 miles
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Nattex
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Re: Front Suspension Question

Post by Nattex »

Thanks. That was my plan for this weekend. I hope it solves the problem because then I need to find an oil leak. I have oil leaking from under the engine. I'm hoping its not an engine seal but it is directly under the engine.
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MikeB
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Re: Front Suspension Question

Post by MikeB »

Look in the shift shaft area. It is a common area for leakage and is easily repairable with a new seal.
MikeB
1998 - GL1500 w/184,500 miles ~ 2017 - GL1800 w/13000 miles
USAF Avionics Communications Tech - 1968 - 1986 / Flight Engineer C-130E - C-141B - 1986 - 1992. Retired
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golden highway
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Re: Front Suspension Question

Post by golden highway »

I think I would start with checking for play in the front end and goose neck. I would then drain the fork oil and fill with ATF it is inexpensive and what Honda calls for in their manual. I found ATF works best for me. The oil might be old dirty and low in one or both forks. If you have oil under the cap I would think you have a bad seal on the air valve allowing a bit of oil to be pushed though. If there is no oil on the fork tubes I would think the seals are ok.
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Bluewaterhooker0
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Re: Front Suspension Question

Post by Bluewaterhooker0 »

If there is no oil on the fork tubes, I wouldn't think an oil leak is probable. Since the bike is new to you, you don't know if or when the fork oil has been changed. I'd start with that. If what drains out looks really nasty, you might want to drain, flush, work the suspension up and down, and drain and fill again, just to attempt for a really clean fill.

Another thought that comes to mind is 'sticktion', as I think it's referred to. That is where the fork tubes are ever so slightly misaligned, causing the fork travel to bind ever so slightly, but will make for a really rough ride, as you describe. I installed a fork brace on my bike a few years ago, and if you are familiar with them, they fit VERY precisely between the forks. My brace fit a bit tighter than I would have liked upon initial installation, causing a lateral outward force, right at the upper fork oil seal. But, I MADE it fit, without making any adjustments to the lower wheel shaft, since the suspension had worked so flawlessly up until that point. Well, when I finished installation of the brace, I had a nice case of sticktion. It is very subtle. Pretty much only detectable with the first vertical movement of the forks from a static position. As you hold the front brake, and apply downward force to the forks, there is this very mild, very slight sticking action of the forks just before they move. That is sticktion. And as subtle, and insignificant as it may seem, it will produce a ride like a dump truck. The solution for me, again not wanting to adjust the shaft, was to modify the brace, ever so slightly, so that it no longer applied ANY lateral force to the fork tubes, which the initial installation had caused. The modified brace slid right into place, with very little effort, and my "sticktion" issue was no more. The bike went back to driving like its original smooth as glass style. If you have a fork brace on yours, that may be a cause, or it may just be that the front wheel shaft was not installed properly after a tire change. Either one will cause the same problem. Just check the fork travel for ANY feeling of unsmooth movement. It should not offer any resistance to vertical travel at any time.

Also, I run about 10psi in my stock spring forks (max 6psi is recommended), and every time I check them, I also have oil at those Schrader valves. The fork oil sloshes around inside and I'm sure some gets to the upper fork, and thus that valve. I don't think that would be a big deal, or any deal. However, I have learned to clear the oil from the Schrader valve before taking a pressure reading. The pressure gauges don't like the oil being shot into them.

BTW, here's a really handy way to change and refill your fork oil WITHOUT having to remove the forks, assuming you have those Schrader valves in your fork caps. I've used it a couple of times with great success.

http://www.goldwingfacts.com/forums/2-g ... right.html
Nattex
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Re: Front Suspension Question

Post by Nattex »

Thanks for all the tips. One thing I noticed while checking for the Sticking you mentioned was when holding the brake and applying downward force the front end compressed a certain amount and never returned. From that point when I applied downward force the springs were making noise (not really a squeak but not sure how to describe).
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Bluewaterhooker0
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Re: Front Suspension Question

Post by Bluewaterhooker0 »

Nattex wrote:Thanks for all the tips. One thing I noticed while checking for the Sticking you mentioned was when holding the brake and applying downward force the front end compressed a certain amount and never returned. From that point when I applied downward force the springs were making noise (not really a squeak but not sure how to describe).
Wow. That doesn't sound too good. That would be more severe than the issue I'm talking about. Maybe your plan A is the better course at that point. Take them apart and find out the condition of all the parts. Good luck.
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Tim 1956
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Re: Front Suspension Question

Post by Tim 1956 »

Nattex wrote: Fri May 12, 2017 1:50 pm I have a new to me 1994 GL1500 with 110,000 miles. I'm in the process of working out some bugs with it. The first being a front suspension that doesn't quite seem right. It is okay as long as I'm on a perfectly smooth road. But as soon as the road gets a liitle rough the front end seems very loose and I feel every little irregularity. I have tried running everywhere from 0-6 psi in the fork and it doesnt make much of a difference. I also noticed some oil under the cap when filling with air. Seems to me that would indicate a seal issue but they do hold air pressure? I think my first thing to try will be to go to a Progressive spring and rebuild the forks. Does this sound like a good first place to start?
I also have a 94 goldwing 1500 interstate with problems of the front end being more clunky on less smoother roads. When I replaced my front fork oil last year after I bought it with 17,800 miles, I drilled and tapped both cap plugs so I would not have the 2 person task and my home made spring compressor of replacing them again if I need to change the front fork oil again or add more. I have noticed when I jacked up the front end of the bike on the center stand to take the weight off of the front wheel and taking out the set screw's and then putting it back in that this pressurized the front forks and the suspension was much better. However this does not last very long even using Teflon tape on the threads and even a small amount of oil leaks out from time to time past the teflon tape. Just did it again yesterday and used the Permatex blue thread sealer and went for another ride. Suspension was nice again. I would love to be able to install Schrader valves to pressurize the front forks because the correct amount of preferred fork oil does not do the trick. I tapped mine out to about 3/8's so don't know if Schrader valves come treaded in that size. Thanks. :?
Tim
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Rambozo
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Re: Front Suspension Question

Post by Rambozo »

Tim 1956 wrote: Thu May 13, 2021 2:46 pm I tapped mine out to about 3/8's so don't know if Schrader valves come treaded in that size.
I'm guessing you tapped it to 3/8-16?
Straight threads like that won't seal, you would need to use a copper crush washer and have good flats on each piece to seal, or cut an o-ring groove.
I think you could just go up to 1/8 NPT. Your hole is a little oversize, but I think it would work. Then you would have a tapered thread that is designed to seal. You can get Schrader valves in 1/8 NPT, 3/8-16 you would have to make yourself.
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Tim 1956
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Re: Front Suspension Question

Post by Tim 1956 »

I have to find the plugs that I got from harbor freight and see what size and thread it is. I check it today while riding around and not a leak at all with the loctight blue. Front suspension is nice again. Hopefully that will fix it. I just don't want to pull those plugs back out again and have them tapped out larger or replace with whatever goldwing had those schrader valves. So much I have never heard of.
Thanks Rambozo. :)
Tim
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Tim 1956
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Re: Front Suspension Question

Post by Tim 1956 »

Rambozo wrote: Thu May 13, 2021 4:00 pm
Tim 1956 wrote: Thu May 13, 2021 2:46 pm I tapped mine out to about 3/8's so don't know if Schrader valves come treaded in that size.
I'm guessing you tapped it to 3/8-16?
Straight threads like that won't seal, you would need to use a copper crush washer and have good flats on each piece to seal, or cut an o-ring groove.
I think you could just go up to 1/8 NPT. Your hole is a little oversize, but I think it would work. Then you would have a tapered thread that is designed to seal. You can get Schrader valves in 1/8 NPT, 3/8-16 you would have to make yourself.
I checked my small box of set screws. it's either 1/4 or 5/16. I'm not touching it now that it is sealed and my front suspension is normal again. Would be nice to pressurize the front forks though. Why not on the 1500 interstates? Crazy. :roll:
Thanks Rambozo.
Tim


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