Fork scratches

Hi Everyone,

I recently rebuilt my forks, with new bushings, new seals, etc. However, I noticed that there are some scratches now on the tubes, in the vertical direction. I tried to take some photos of the scratches, but it was not possible to see them in the photos; they aren't very deep.

I'm concerned---the new parts should be much better than the old ones, and there weren't any scratches on the tubes before, despite the forks having been severely neglected for 25 years. I don't know why this happened, so I took the forks apart to investigate (yeah, again...)

There was no obvious reason for the scratches, although there was crud on the dust and oil seals. I am thinking that the crud (road grime, based on its appearance) was just rubbing up and down on the tubes as they moved and causing the scratches. I was worried because I scratched some of the teflon off one of the bushings when I installed it. It doesn't seem like this had any bad effect, but I'm replacing it anyway.

The other possibility is that there was crud in tubes that didn't get completely washed out when I put the forks back together.

Here's what the oil looks like that came out of them:



And here's the stuff that was floating in the bottom after I let it settle:



This does not look very good to me. I am thinking that with all the cleaning and polishing I did when I refurbed them that I loosened up some crap, so now I'm glad that I opened them. If the community approves I will clean everything again and put it back together with new oil.

Thoughts? Should the oil be that dirty? Does anyone else get scratches on their fork tubes with properly functioning forks?

Thanks.

 

it doesn't take long for that oil to get dirty. are you sure you cleaned them out real good last time? mine had hard crud in the bottom that took a stick and garden hose to get out. the dust caps should keep almost all the dirt from the seals.

 

The stuff in the oil looks like aluminum dust to me. I polished the insides of the lower tubes with aluminum polish, but I seriously cleaned them for ages, so I'm surprised that there was that much stuff. I mean, it could just be dust and whatnot, but I still suspect metal filings/little bits of rust for these scratches...

 

see if it sticks to a magnet

 

Check the bushes are doing their job.

 

I recently dismantled the forks to see why th oil looked metallic after 3 changes in 3 years -- trying different weight oils -- and the top bushes in th lower leg were worn on the out side, one more than the other ie. loose in their mounts, another dodgy problem that i've found from th factory.

Now, new bushes that sit very firm in th mount, gaiters on and kept th dust seals.

 

I'll tip my hat to Polock for the magnet comment. Indeed, the heavy junk at the bottom of the oil was ferrous, and I do think it was rust/metal filings. I have no idea how rust could have gotten into the system after I did the refurb, because everything sealed up really nicely (and the aftermarket red oil seals are super duper tight). I don't really think it's super likely that dust or aluminum dust could have scratched the chrome, so I have to conclude that the rust in the oil was responsible for the scratches, and that the rust was still somewhere in the system when I put it back together. I guess I didn't clean it out well enough, so it's time for another round of squeaky clean...

 

inside the upper steel tubes? maybe you put the springs in opposite what they were and they were rubbing where they never rubbed before?
the books say smaller coils up, i do smaller coils down