Very bad fork knocking from the inside...

[IronFox102]

Hey guys, first post on this forum, though i have been lurking for a long time. Ever since i owned my first suzuki, an 81 gs750. Always got great info here. Anywho.... now i've got an 85 GS700 with the air-ride front end. I noticed right away when i first bought the bike and was loading it up in the truck that there was a bad banging/clunking coming from the front end. Fast forward a few months and now that i've got the bike running and driving, and the front end air-ed up, the knocking still persists.

If i sit on the bike, hold the brake and thrust down hard, i can feel something inside the fork BANGing into the top of the tree. I figured the last guy may not have assembled them correctly so i pulled them. When i dropped the wheel, the forks de-compressed out to their full extension position, and once in hand i was able to compress them back and forth. The spring is definitely in there alright. I gave the triple tree's a good jiggle to make sure the bearings weren't bad. Doesnt seem to be the case.

On the road test, with the forks aired up to 3 or 4 PSI, the little cracks in the road i cannot feel, but if i hit even just the littlest bump the entire front end is hit with an extremely rattling BANG, which translates right into the bars and up my wrists. Ouch.


So that's my situation guys. I dont know a whole lot about these forks. So before i pulled them apart, i wanted to see if you guys had any words of wisdom to share. Cheers!

 

[Crankthat]

With my limited experience with this subject two things come to mind off the bat.

Probably a stupid question but just in case, correct level of fork oil?
Second would be what weight fork oil.


Probably someone else will get you sorted.

 

[Guest]

Pull the forks off and take them apart, check for the right pre load spacers at the top, check the springs is one snapped in half? Check the internal slider bushings and the bushing at the end of the inner tube. Something isn't right. While the forks are off, pull the steering head off and service the steering head bearings, check the wheel bearings as well. Look at the brake caliper mounting bolts are they good?

 

[IronFox102]

I got the front end taken apart, but first and foremost, my wheel is badly bent. I put it on the true-ing stand and sure enough, it's out like a son of a gun. Going to have to be replaced. I have on-hand a GS500 wheel from a previous project, do you guys know if a mid 90's GS500 wheel will work on this GS700? I havent got back to try it out yet.