Problem disassembling 938750 fork

[Rusty]

Hello, I decided to tear down my 71 b+ for the winter and do a rebuild. I have fork seals and I'm taking the forks apart, but I can't seem to remove the 6mm hex screw on the bottom. It just turns. I drained the oil replaced all the parts as stated in the manual.

[BrianZ]

Are the forks springs installed? It's easier to remove the screw if the springs and fork cap are installed, as it puts a bit of pressure on the damper rod.

Brian

[Dale]

Yes, you will need the pressure from the spring installed. Then I find that a cordless impact driver/drill is just the ticket. Pneumatic would be great too. If that does not work, you could add a small spacer to the top of the spring to apply even more pressure.

[Rusty]

Yes I put everything back together. It spins with tension, but never gets loose. I will see if I have a bit for my battery powered impact drill. What recommendations for oil? A local shop from the sixties is liquidating so they have a bunch of different oil. But I'm sure there is modern oils as well.

[Zyx]

So many modern damper fluids out there that I wouldn't worry about really old stock. Forty years ago we used what we had, from fork oil to ATF to motor oil. These days you can find high zoot damper fluid in any weight that works for you. I rebuilt a year ago, same forks as you have, and it was recommended that I use 20W fork oil. At 150 pounds I found this way to stiff, and have dropped to 10W, even though forty years ago I used to use 30W motor oil. Times and perspectives change. 10W fork oil gives me a pretty plush ride, and I guess I don't ride hard enough anymore to bottom the forks, even in motocross.

The bottom bolt can really only be extracted one of two ways: you have to have a pickle fork ( probably there is a real name for the tool but I don't remember it) made to hold the damper rod still while you twist the assembly bolt (pain in the but even if you have such a tool) or an impact gun, electric or air. I use an air powered butterfly gun which works a treat. I don't think it makes more than maybe 30 pounds of torque max. It was used as an assembly/disassembly gun back in the 70's when they didn't really have electric impact screw guns like they do now, but it serves the same purpose.

[dirty_rat]

I have found that for holding the damper units which want to turn with the screw (making it impossible to remove), I leave the forks assembled. I then attach a ratchet tie down to the handlebars and the other end to the fork lowers (I attach it to a small bracket attached to the screw bosses attached to the lower leg). I then ratchet up the tie down about an inch or two. This gives plenty of resistance to the damper rod and the screw will now back out.

[taber hodaka]

That sure works good for me-------Clarence

[Rusty]

Thanks!! Found a 6mm for my impact drill. Voila!! Now clean, new seals and figure out how it all goes back together. I'll have plenty more questions this is my first tear down and rebuild. Most of it will be pretty straight forward. New cables, brake shoes, tired, etc. when I get to the engine which is already disassembled I'll be brain picking.

[Zyx]

You have to love a basket case. By the time you complete the assembly, you will know your machine.

Do you have a shop manual of any kind? You will need torque specs, and there are a few caveats you will need to know, but othwise not a difficult engine to work on.

[Rusty]

Yes I do, (have a manus all) this was my first ace. Then I ran across another. When I started having problems with this one it became a parts bike for the latter. The latter is the one that the stator has been giving me trouble. So I decided to switch gears and go whole hog. I've been trying to get ahold of Roger Lippiat to send my stator to because he lives in Ohio and has done previous electrical work for me. I can not seem to reach him. I'm really looking forward to this project even though I know there will be plenty of road blocks. Thanks!!!

[Rusty]

I guess I do have a question. How do you separate the inner and outer tube?

[Dale]

With the Allen screw removed and the seal carrier nut off, the inner and outer will seperate with a good jerk on the inner tube. You can either just hold the outer tube or you can place the outer tube in a vise (carefully, with either wooden jaws or wrapped in a towel). With a solid hold on the outer tube, pull the inner tube out until it stops, then push it back in about 4 inches and then pop it back out. It will seperate.

[Rusty]

So I realized I need to remove the collar that holds the oil seal. I don't have a "strap wrench" and my vice isn't bolted to me table. Any tricks of the trade. Probably time I find a good place to mount my vice. When I make knives I move it around even though it's kind of big, but that seems to have its limitations. Thanks almost there.

[Dale]

I would recommend a trip to your favorite tool store for a rubber strap wrench. Then, I have found that it is easiest to break the nut free before removing the forks from the bike. If you already have the forks off, then put them back in the triple clamp and install the wheel. Then you can use the strap wrench on it. A little heat from a heat gun will help if you find it to be stubborn.

One of the old manuals shows using locking pliers on the nut on the surface that is not normally seen (under the dust boot). Again, I would use a rubber strap wrench.

[Rusty]

Thanks, I figured I'd be off to the store!

[hodakamax]

Rusty, I have sucessfully used a couple of layers of old inner tube in the jaws of channel-lock pliers. Also you might sqiurt a bit o WD-40 on the threads. It' worth a try.

Max

[Rusty]

So I got the fork outer nut off after I got my vice mounted. Man the fork oil seal was heck to get out. I'm still trying to dig pieces out. I have new fork seals minus the inner o ring. For some reason I didn't get it when ordering. My question is anyone have a pic of the fork seal? The one I dug out looks like it has a lip on the top. The one I have doesn't. The invoice has the right part number though. Thanks.

[Zyx]

Original seals were steel bodied. New manufacture isn't. The old style is available (or at least can be made) but only if you find a source through seal distributors. The new ones seem to work once properly installed, just make sure there is no oil between seal body and steel fork seat or they will pump out.

[Rusty]

Man what I thought would be easy is turning out to be a chore. viewtopic.php?f=1&t=617 Wish I would of found this awhile ago, but I wouldn't have helped. I finally got all the old seal that was fused in the nut. Trying to put the other seal in. I used a board, I used a vice. I couldn't get the bugger in there. To the point I damaged the seal. It appears to be nos. because it has a metal ring in there. I have another for the other fork, but they are so stiff. It even look like I may have bent the lip slightly where it seats!!! Also to take a break I took apart the other fork. It had hardly any oil and the top long spacers appears to be stuck. Any tips? Thanks!!

[Dale]

Rusty,
Sorry to hear that your seal replacement is not going so well. I do know that the old seals can be a real bear to get out. I have soaked the old seals in penetrating oil for days and then apply heat with a heat gun. After that, I have used a large socket with a short extension to drive them out. It takes some serious patience.

I am a bit confused by your post regarding your new seals. Are you saying that you have a new set with the metal outer ring? And are you saying that the rubber in the new seals is hardened? If so, I would say scrap them and order a new fresh set of all rubber seals. They do work just fine as long as they are installed dry as stated by AZ earlier.

When you install the new seals, it is best to use a seal driver. If you do not have one, a short piece of thick walled pvc works great. Just take your seal to the hardware store and find a size that will work. Then place your new seal into the carrier nut, put an old seal on top of it and finally use your driver on the old seal to push the new seal home. This helps protect the surfaces of the new seal.

As for the stuck tubes... I have not encountered that before. Perhaps soaking and heat would work here too?

[Rusty]

Thanks, yes it was a bear. There were orchestra in there I pretty much burned to a crisp then picked out. Got some fine sandpaper and finished the job. I bought the seals a couple years ago from Paul. I thought I got everything but I did not get the o rings for the seal nut we are talking about. The oil seals have like a metal spring in there. Are these new or old. They are pretty stiff either way. I'm not sure how flexible they are supposed to be but these are far from it. I have been hearing and oiling the other fork and trying to be patient. Thanks

[Dale]

Yes, there will be a very tiny metal spring inside of the seal whether it is a new or old type seal. The metal that I was referring to would be a metal band around the outside of the seal. This type of seal (which is the original type) makes a metal to metal fitment which may be the best but as you have learned, are really hard to remove after being in place for years. Most of the seals that are available today do not have the outer metal band and these are the ones that you do not want to lube or oil the outside surface or they will not stay seated in the carrier.

It sounds like the seals that you have do not have the metal outer band. Is that correct? As for how stiff the rubber is, I would guess that if you purchased them in the last couple of years that they should be fine. I think the trick is to be very careful driving the seal in. Again, use an old seal on top of the new seal and then a seal driver against the old seal.

[Rusty]

Thanks yes than they are newer seals. Looks like I need at least one new one! Forgive me but what is a seal driver. And is there and alternate method not using one. Thanks for all the help. I'm almost there. The post I linked said 15 mins!!!!! Ha. It's been days! I'm learning though.

[Dale]

Go to Google and search for "fork seal driver" and you will get many pictures of them. However, for the 30mm Hodaka forks, it works just at well to get a piece of thick walled pvc pipe matched size wise to give you good coverage on the seal as you tap it in. The idea is to not deform the seal, but press it into place with even pressure. If you can not find a piece of pvc you can accomplish the same thing by using a large socket, but instead of placing the socket directly on the new seal, place an old seal on top of the new seal and tap it in.

[Rusty]

Heard chef! I will try again with the ruined seal and the new one.