Topic: 6mm allen bolt on bottom of fork!

[Nortstudio]

1976 CB550K

I read all the tips, watched all the videos, followed all the instructions, but despite all that, I still had the hardest time getting the 6mm bolt out of the bottom of the fork.  Man, that thing is a #$%*!  Stripped one side, despite every effort to avoid it.  Still got it out eventually, but will have to replace it.

My question is: how tight do these things have to be in there when replacing them?  If getting it out is any indication, I should be hiring the Hulk to wrench it down!  The manual says a 6mm hex should be 5.8 - 8.7 foot lbs.  Is that right for this bolt as well?

Thanks,

scott

[KingCustomCycles.com]

That allen has a copper crush washer for sealing.  I put mine in at about 20 inch pounds and have had 1 leak in over 60 jobs.  I think that one was due to a distorted copper washer from previous overtorque.  I apply 3M aluminum anti-seize also to save future owners the headaches.  Does the manual list a specific torque in the fork section?  I forget.

[Nortstudio]

Thanks King!  You are saving me on this fork debacle  

I only found the specifics for generic 6mm hex, so not exactly the fork.

Anti-seize for sure - and anything less than it was should be better for me, and anyone else in the future!

Appreciate it.

[MCRider]

Yes, I suspect that the difficulty in removing the bolt came from a seizure of the bottom of the allen head to the fork leg. (steel to aluminum with road crud corrosion) Not due to a high amount of torque used in assembly. Use the anti-seize, esp see that a small amount gets on the bottom of the Allen head. Then tighten like a regular bolt and move on.

Had you inverted the leg and dripped a little penetrant into that cavity and let it sit, I'd bet it would've come out easier. It could've broken the seizure.

[Nortstudio]

I absolutely wanted to do that (I'm all about penetrating oil), but everything I read showed loosening the bolt while still on the bike. In the end, I had to remove it and get it off in the vice - so I could have done this all along. Live and learn...

[cameron]

+1 anti-seize.
+1 inverting it and using penetrant.

and I think a good bit of general advice on these bikes:
I have found that EVERY TIME I have a problem with a fastener, it is fused to the CASE.. not an actual stuck-threads problem..... which means in every case, drilling the head off is a rather trivial solution to the problem. Every time I have done it, I easily twisted the shaft out with my fingers. So drill baby drill?

If you have replacement fasteners, that is.
www.stainlesscycle.com

[BobbyR]

Scott, a broom handle works well for loosening and tightening that bolt at the bottom.

[Nortstudio]

Thanks guys. I'll let you know how it goes reinstalling it. Need to find a replacement, hopefully Fastenal.

[Duanob]

I had to drill the head off of one that was corroded on. I pulled the innards out of the fork and was able to remove the remaining bolt easy enough. Just put a new bolt and copper washers in when reinstalling everything.

[slikwilli420]

Fastenal was mentioned as a place for replacement bolts, but I want to do a shout out to Allen at allensfasteners.com. The selection of stainless allens is superb, and they have a great selection of specialty bolts like the stainless steel 12 bolts from ARP. Also know that I am not affiliated with this company at all, Im just a guy on the street that hates getting screwed on bolt prices.

[Nortstudio]

Good tip willi. I chose Fastenal because they are local - and I could get them back together immediately. But that place seems good for the future.

Thanks.

[chickenman_26]

I could be wrong, but I believe you'll find that damper rod bolt is an 8mm. It takes a 6mm Allen wrench to remove it. Having to drill the head off is pretty common on these old bikes. Don't use a stainless replacement. Just get a zinc-plated one of the correct length from any hardware store, and replace the copper crush washer. Clean the threads in the bottom of the damper. Specs call for a medium strength locking agent on the threads and torque to 14 ft. lbs. Don't even think about 20 inch pounds (1.67 ft. lbs). Leakage isn't the main issue. The damper rod is subjected to pretty severe pounding as the forks top out, and that bolt needs to be tight to specs. Perhaps King is referring to the oil drain bolt - which actually is a 6mm bolt with a 10mm head.

Stu

[Nortstudio]

That was my mistake. It is indeed 8mm (with 6mm Allen). I got a replacement and it should be good. Thanks for the heads up.

[MCRider]

I could be wrong, but I believe you'll find that damper rod bolt is an 8mm. It takes a 6mm Allen wrench to remove it. Having to drill the head off is pretty common on these old bikes. Don't use a stainless replacement. Just get a zinc-plated one of the correct length from any hardware store, and replace the copper crush washer. Clean the threads in the bottom of the damper. Specs call for a medium strength locking agent on the threads and torque to 14 ft. lbs. Don't even think about 20 inch pounds (1.67 ft. lbs). Leakage isn't the main issue. The damper rod is subjected to pretty severe pounding as the forks top out, and that bolt needs to be tight to specs. Perhaps King is referring to the oil drain bolt - which actually is a 6mm bolt with a 10mm head.

Stu

Thanks, we'd been playing fast and loose with that 6mm thing, its actually an 8 as you say. My torque table already posted has 8mm at 10-18 ft/lbs. Your 14 ft lbs being halfway. 

I don't doubt that you're correct, but I'm wondering what your "spec" source for the locking agent and 14 ft/lbs is. In early books the damper rod isn't even acknowledged as being in existence (not on any microfishies). I didn't find it in my Clymers (thru 1977) but could have missed it.

[BobbyR]

The torque on that bolt is fairly irrelevant. You want it tight enough to not to leak.Get it tight and give it the two finger torque. It cannot loosen and fall out on the road, the axle is in the way.

The bolt is best removed with the fork tube removed. Once you have the wheel off the tubes come out easily. You can then capture the inner tube with the end of a broom handle. You have ergonomically better access to the bolt with the fork off the bike. You can heat it, penetrate it, and be sure the Allen key is firmly seated and can put a vise grip on the end of the key for more leverage.   

[ekpent]

About half or more of those bolts I have removed, which is quite a few, have required me to put the fork bottom into a soft jaw vise to get them to the first intial break loose point than as Bobby has pointed out ,get the old broom handle for the rest and also snugging back up.

[Nortstudio]

I was able to tighten it up on the vice, with the cap installed. Is that wrong?  I didnt need a broom handle.

[MCRider]

I was able to tighten it up on the vice, with the cap installed. Is that wrong?  I didnt need a broom handle.

No, that's how i do it. With the cap and spring in you don't need the broomstick. Either way.

[chickenman_26]

I was able to tighten it up on the vice, with the cap installed. Is that wrong?

Not wrong. That's the best way to get the damper rod to hold still.

Stu

[chickenman_26]

Thanks, we'd been playing fast and loose with that 6mm thing, its actually an 8 as you say. My torque table already posted has 8mm at 10-18 ft/lbs. Your 14 ft lbs being halfway. 

I don't doubt that you're correct, but I'm wondering what your "spec" source for the locking agent and 14 ft/lbs is. In early books the damper rod isn't even acknowledged as being in existence (not on any microfishies). I didn't find it in my Clymers (thru 1977) but could have missed it.

Where did I get the specs? Early service manuals were notoriously poor on torque specs. But all of the more recent factory service manuals for Hondas and other makes using this same arrangement list the same torque specs (some makes use 16 ft. lbs) for that 8mm damper bolt. You may even find it in the Honda Common Service Manual. As I said above, leakage is not the main issue. The damper rod or cartridge has to be held perfectly centered and very tight to the bottom of the slider. "Snug" won't cut the mustard.

[BobbyR]

I was able to tighten it up on the vice, with the cap installed. Is that wrong?  I didnt need a broom handle.

Nah, unless you break something you did nothing wrong. Most times the springs don;t have enough friction to keep the tube from spinning. Chickenman is right, if it comes loose you lose or your fluid.

In his world he had to check his control tubes, pitch horns, swash plate and Jesus nut.     

[CBNJ74]

I was able to pull this off without the use of a broomstick handle or vice. Luckily for me the pressure of the spring kept the rod in place and the screw untightened and tightened back up nicely. I left the tubes in the trees as well.

[Nortstudio]

I guess i was lucky with this one. Got it tightened no sweat.

Now, if only I could get a definitive answer on the amount of fork oil for year new Progressive springs, I'd be a happy camper. I've heard everything from 130cc to 190cc. I'm just about in the middle, maybe that will work

[CBNJ74]

I used around 7.5oz with stock springs. Your tubes and lower legs are probably a difference size so the amount might be different. It could end up being a preference/body weight thing as well. I'm pretty new to this CB thing so I'm learning as I go.

[scunny]

I'm concerned about BobbyR's facination with broom handles.