Was just reading an article on this last week. Click on "AirLore" on the blue line at the top of this page. From the menu select Technical Tips. On the search box enter "front end clunk". Select the first article.

My bearings seem very tight and it's definitely coming from front shock. I saw one article about 80s airheads being famous for this clunk but mine is a 78. Maybe a tech day in Portland would have an answer

Now incorrect assembly could possibly be the problem if the entire fork internals were disassembled. But fork internals aren't usually disturbed on a casual fork leg seal replacement job. There may be no way for you to learn at this date how extensive the older repair really was.

On a bet that it's a simple fork fluid issue (not enough or wrong viscosity), I'd drain and pump out the fork legs (while on the bike) and re-fill each leg with 250cc of ATF.

• ATF is cheap, and if it comes to disassembly you won't mind loosing it.
• ATF is about the correct viscosity.
• If AFT makes for a cure, it will mix well with real "fork oil", if you care to re-fill it weeks later.

To measure and re-install the fluid, you might want to invest in a very large (200cc ?) veterinary syringe, available at your local country drug stores, or on Ebay under "fork oil".

Draining both sides will require about 15 minutes. Refilling time will be determined by the fluid installation tools.

Thanks for all that. I'm gonna get the crush washers before I do the oil change. I was thinking that might be the culprit...

The oil for my left Fork came out looking like weak coffee. And nothing came out my right side at all. So that's a mixed message, I hope the seal is okay inside and when I put new fluid in it it doesn't drain right back out on the ground. Pretty weird, no wonder I have such a clunking noise coming from my shocks

The oil for my left Fork came out looking like weak coffee. And nothing came out my right side at all.

The brownish look is usually caused by water in the oil, usually from washing the bike with high pressure hoses. Don't ever do that. For many reasons, pressure washers are death to motorcycles.

No fluid is the more serious issue. It could be a forgetful owner/mechanic, or a serious leak. You won't know until you refresh the levels. Let's not intentionally make things hard. Simply install the 250cc of ATF and watch. It could be nothing at all. Stranger things have happened.

😉

Well, the right side was full at 190cc. To the top. So I was thinking that maybe a seal is stuck and that a quick ride with fluid in there might loosening up. So I came back and there was fluid running down the fork from the seal. So I tried drain some fluid back out and nothing came out. Full to the top and no way to drain. Grrr

Okay, I let it sit for a couple hours and came back w a small syringe to siphon out some of the excess oil. When I looked in the hole it was empty and the inch and a half long syphon didn't hit any oil! So I added the 60cc that I had left over and it all went in. So maybe the shocks are still shot but I got all the fork oil in. So it must have loosen up a bit. The bike sat for a long time, like 2K in 12yrs. Thanks for all your help.

You should have stopped when you saw the forks were full of oil. Of course oil came out the seals, it had no where else to go.

So are you draining these forks by removing the 13mm nut from under the rubber cap on the bottom of the fork leg ? That's not enough. You also need to take the 4mm hex key used to hold the stud and push the threaded stud up, and back into the fork leg. You are pushing against the fork spring. It can be very tough, especially if you have heavy fork springs.

Doing this, I can get mine to sort of balance in the "open" position. Then I have to hold the front brake and pump the front forks. If you cannot get yours to stay open, then your job may require 2 people: one to push up on the threaded stud, and another to do the fork pumping.

Hope this helps.

Wow, that helps a lot. Thank you very much. I was thinking I'd have to take the right fork apart because something was stuck. The left fork drained easily by just removing the nut.

You'll want to use the same procedure on both sides. Take the 13mm nut all the way off. There may also be a wave washer too. Then using the 4mm hex key, push the stud up into the fork leg and it may catch open.

You'll want to position a rectangular drain pan, front to rear, right along side the front tire. A paint roller pan works great. If you have 2 pans, then do both sides at once. When you're pumping away and it's nearly empty, a thought about bad diarrhea will likely pass through your mind. That's what it sounds like. Pump until empty and let it drip for about 2 more minutes, then fish the stud back down and re-install the washer and nut. It only takes about 10 ft-lbs of torque to adequately re-seal the stud. You had issues becasue the last guy over-torqued.

Be sure the rubber cap goes back on correctly and is fully seated.

I successfully drained the oil from my right fork thanks to your advice. It just poured out after I loosened both of the 13 mm nuts. The forks dropped and oil poured out on the right hand side. The right side refilled very quickly and easily. The left side took at least 10 minutes of pouring really slow and waiting for the funnel to drain and then pour again. They both filled up and now there's no clunk coming from the front shocks. Now there's a couple different rattles from under the tank and that bugs me too but one thing at a time. Thanks again

They both filled up and now there's no clunk coming from the front shocks.

Congrats !!

Now there's a couple different rattles from under the tank and that bugs me too, but one thing at a time.

A rattle under the tank can be very serious, becasue it often means something (no matter how dull the edge) is eating a hole into the underside of the tank. Doesn't matter that it's steel, it will eventually wear right through. The welded repair will be bad enough, but the cost of repainting will put you right into the cardiac ward at the local hospital for several weeks. So you'll want to look into that SOONER rather than later.

The usual suspect is the front tank mount rubber... worn or slipping out of place. Order a new rubber part and then use silicone sealer to adhere it to the post where it sits on the frame. This will keep it in the proper place during tank replacement.

Also look for bright spots in the metal on the underside that give clues to items touching. Nothing but rubber should touch the tank !! Second most likely is the master cylinder not being re-fitted far enough forward after a rebuild. Loosen the band and make sure it's in the full forward position.

While you are there messing with the brake m/c, you need to know that these often leak over time. The problem is that they drip caustic brake fluid right onto some VERY IMPORTANT parts of the wiring harness. No doubt, lots of paint is missing due to the brake fluid. You may also see a strange, gelatinous, mucus-like coating on the electrical wiring, especially on the LH side. That's old brake fluid, which MUST be removed. Hot, soapy water and a scrub brush work great.

It is especially important for owners of 1978-1982 (?) model bikes that included the "mini-cube" plug-in starter relay located on the LH side, directly beneath the brake m/c to pay attention to this area. Read More By Clicking Here for a very informative article on the subject.

It's simply best to be aware. 😉

I want to thank you for all your help. My front shocks are now very quiet. Although, when I pull it up on the centerstand there's a looseness type clunk coming from the steering head area. The bars turn very smoothly without any feel of pitted bearings.
I removed the tank. The master brake is as forward as it can go and still allow the tank to go back on. The tank rubber actually looks pretty good but I did contact cement an 1/8" thick piece of rubber on the top half to solidify the tank and raise it a fuz. There is obvious rubbing about the middle of the underside of the tank from the cable running along the frame. Everything is super stock and very clean under the tank. Maybe if I put a couple washers under the rear tank connection rubber to raise it a bit?? There's a very pronounced low RPM rattle that comes from the tank. Maybe 1300 to 1700 RPM and then its gone. This bike sat for a number of years in a warm dry garage. 2k in 12 years.