The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: clouseau on October 04, 2009, 03:03:07 PM

Title: Forks - overfull = noisy??
Post by: clouseau on October 04, 2009, 03:03:07 PM
I had a BMW mechanic replace my fork seals. He primarily works on pre '79 bikes but he claimed to have done the job on several R65s.
The forks have been noisy on every little bump after I got it back and before the seal change, I would just hear a clunk from bigger bumps or dips.
So I assumed he didn't fill the forks with enough oil and since I had no idea how much he put in, I decided to drain them so see how much was in and refill to the proper level.  
I drained the right fork and 10oz or 295cc came out with a bit of sludge as well.  So much sludge I the drain was clogged. And 100cc over recommended level!
So my question is would too much oil make for noisy forks or did he leave something out during dis-assembly of seal change?
Title: Re: Forks - overfull = noisy??
Post by: Bob_Roller on October 04, 2009, 03:59:36 PM
It shouldn't make the forks noisy .

If there was black sludge in the forks, it doesn't sound like he did a thorough job on cleaning the internal parts .

That black 'goo' is usually a bump stop washer, that deteriorates over time .

Have you taken the bike out for a ride since you drained the oil ?

I would have my doubts about the work that was done, as he didn't know the proper quantity of oil to put in the forks .
Title: Re: Forks - overfull = noisy??
Post by: Barry on October 04, 2009, 05:19:30 PM
I'd say an overfill to that extent would make them very stiff and could make them noisy.
I find it best to measure the level with a dipstick in fact I just use the dipstick of my car and aim for 35 - 40mm of oil above the top of the piston.
Title: Re: Forks - overfull = noisy??
Post by: clouseau on October 04, 2009, 05:33:55 PM
The mechanic definitely changed the seals and at least added oil from the signs of oil residue around the triple tree when I got it back.

I drained and filled them to 190ml and took it for a spin and yes they are quieter.  In fact, it seems back to 'normal.'
When I compress the forks with the bike on its stand and quickly let it fully extend it slams back with no sign of cushion so it's safe to assume the stop washers are no longer. That's another project for some other time.
At least the fork seals and oil are new and the proper levels now.
Thanks for the help as usual.  Love this forum.  :)
Title: Re: Forks - overfull = noisy??
Post by: williamemack on October 04, 2009, 08:23:41 PM
Barry and I, among others, have early R65s the have a fork "clonk" upon rebound...usually a depressed manhole cover. I had my forks stripped last fall. New seals, rebound bumpers and shimms, plus fresh 7.5 wt fork oil didn't stop the clonk. I guess I have learned to live with it.
Title: Re: Forks - overfull = noisy??
Post by: Rob Valdez 79 R65 on October 04, 2009, 10:36:45 PM
This story reminds me of two things:

;)