How The Hell Do You Remove The Fork Bottom Allen Bolt?

What kind of design is this where there's a bolted joint, but no way of holding both sides of the joint? The bolt is slightly loose but the whole cartridge inside the fork is just spinning. I tried using an allen wrench onto a drill and all it does is spin. Never backs out. I don't have access to an impact, although every impact I've ever used has required a wrench on the other side to actually do anything. What a stupid design.

If you put an allen wrench into it then hit it very sharply with something metal, ie a mid sized wrench, sometimes the inertia of the inside piece will be enough to overcome the friction of the threads. Essentially, you want to duplicate the action of the impact. This may take several hits to do the job.

Put the springs back in and put the top cap back on, and hit it with an impact wrench. Hopefully having the internals in place will put enough tension on the cartridge to allow the impact wrench to back the screw out.

It sounds like you have removed the fork cap?

If you replace the spring and fork cap, this should provide enough resistance for you to remove the bolt after it has been loosened.

I went through this recently. Thought I had loosened it enough before taking fork apart, but had not. I reassembled the tube with the spring and cap and still couldn't get it out, even with an impact gun. Disassembled it again and cut a taper into an old broom handle. Was able to wedge the broom handle between the cartridge and the tube and then was able to break it free with the impact gun.

Conedodger

I went through this recently. Thought I had loosened it enough before taking fork apart, but had not. I reassembled the tube with the spring and cap and still couldn't get it out, even with an impact gun. Disassembled it again and cut a taper into an old broom handle. Was able to wedge the broom handle between the cartridge and the tube and then was able to break it free with the impact gun.

This is about the only thing I can see working. To everyone else, tried it tried it tried it and tried it. I have stiffer springs, I put the cap back on, put preload on max, put a jack UNDERNEATH the bottom of the fork tube to get as much force onto that cartridge as possible, and no luck. What a piece of shit design. I had an old Yamaha YZF-600R that was easy to remove with a lock nut on the end of some all thread that you put inside the fork and onto the cartridge. This design, no such accomodations.

I guess I'll try a broom handle and take it into work tomorrow where there is an impact. What a waste of a day off because of a shitty design.

Showa had been building forks of such design for ages and Honda never found it neccesary to request for any changes all those years to make it easy for the home mechanic to remove that lower bolt........ I guess Honda Motor Corporation just assumes all buyers of their bikes just go to their dealership service departments for everything that needs servicing on their bikes. I suspect service departments will be quite ticked off if all the "special tool" notations on the Honda Service manuals dissapear too....... Customers, what the hell do they know anyway........blehhhh.

Beck

Showa had been building forks of such design for ages and Honda never found it neccesary to request for any changes all those years to make it easy for the home mechanic to remove that lower bolt........ I guess Honda Motor Corporation just assumes all buyers of their bikes just go to their dealership service departments for everything that needs servicing on their bikes. I suspect service departments will be quite ticked off if all the "special tool" notations on the Honda Service manuals dissapear too....... Customers, what the hell do they know anyway........blehhhh.

I was going to suggest a special tool to do this job. This doesn't even have the option for a special tool!

I shaved down the end of some wood round stock I had and stuck it between the end of the cartridge and the inside wall, ala Conedodger. When I turn the socket head screw, I don't see the cartridge rotating inside the fork anymore. And yet, the bolt doesn't come out. Last option is an impact or I throw this bike in the trash.

Sometimes it just gets worse. When working on a friends '95 VFR750 forks, the allen head stripped out and we had to drill out the head off of the bolt to remove it. On my '09, I left the forks in the triple clams, tightened the preload all the way and the bolt came right out, this BTW was the same procedure we used on the 750. I attribute the difference in ease of removal to time...I'm 99.99% sure the VFR750 forks were never serviced (not my friends doing, he bought it used) and that my '09 were a lot "fresher" not having time for the bolt to "seize" up.

joeystalin

Beck

Showa had been building forks of such design for ages and Honda never found it neccesary to request for any changes all those years to make it easy for the home mechanic to remove that lower bolt........ I guess Honda Motor Corporation just assumes all buyers of their bikes just go to their dealership service departments for everything that needs servicing on their bikes. I suspect service departments will be quite ticked off if all the "special tool" notations on the Honda Service manuals dissapear too....... Customers, what the hell do they know anyway........blehhhh.

I was going to suggest a special tool to do this job. This doesn't even have the option for a special tool!

I shaved down the end of some wood round stock I had and stuck it between the end of the cartridge and the inside wall, ala Conedodger. When I turn the socket head screw, I don't see the cartridge rotating inside the fork anymore. And yet, the bolt doesn't come out. Last option is an impact or I throw this bike in the trash.

I had the same frustrations. Take a breath, try again, repeat. You'll get it eventually.

joeystalin

Beck

Showa had been building forks of such design for ages and Honda never found it neccesary to request for any changes all those years to make it easy for the home mechanic to remove that lower bolt........ I guess Honda Motor Corporation just assumes all buyers of their bikes just go to their dealership service departments for everything that needs servicing on their bikes. I suspect service departments will be quite ticked off if all the "special tool" notations on the Honda Service manuals dissapear too....... Customers, what the hell do they know anyway........blehhhh.

I was going to suggest a special tool to do this job. This doesn't even have the option for a special tool!

I shaved down the end of some wood round stock I had and stuck it between the end of the cartridge and the inside wall, ala Conedodger. When I turn the socket head screw, I don't see the cartridge rotating inside the fork anymore. And yet, the bolt doesn't come out. Last option is an impact or I throw this bike in the trash.

Does the bolt move up and down at all?

This is pure theory. The bushing is loose and is just spinning in the cartridge now. Holding the cartridge in place isn't going to do anything anymore. If the circlip is still in place, you could try using the damping rod to hammer the bushing back on to the circlip to jam it up again.

Worse case try drilling it out. It's just a standard 8mm bolt.

Yeah, I will try an impact and then drilling tomorrow. But I really hate drilling out bolts. There's always the danger of damaging surrounding material.

The bolt doesn't move up and down at all.

Here's a little drawing of a the major components of a cartridge fork:

[image: post-362-0-24116800-1380831615.gif]

Note that the Bottom Bolt threads into the Compression Valve Body, which sits inside the Cartridge Tube. The Compression Valve Body is not attached to the Fork Cartridge. The Compression Valve Body is free to spin within the Cartridge Tube.

When you try to remove the Bottom Bolt and it just spins, what is happening is that the Bottom Bolt and the Compression Valve Body are spinning together.

How can you stop the Compression Valve Body from spinning?

If you press down on the Fork Cap, the Stanchion Tube moves down and the Fork Spring puts pressure on the top of the Cartridge Tube. Press down hard enough and the Cartridge Tube will be firmly seated against the bottom of the Lower Fork Tube.

Which does nothing, because the Compression Valve Body is still free to spin within the Cartridge Tube, and no amount of additional pressure on the Cartridge Tube will change that...

So, what can you do?

Two options:

1. Try pulling the forks apart, rather than compressing them. I have not shown it in the drawing, but there is (on most bikes) a Top Out Spring located on the outside of the Cartridge Tube. There is also an Oil Lock Piece at the bottom of the Fork Stanchion, which catches on the Top Out Spring at full extension of the forks (the spring is there to soften the blow), and by putting the fork under tension, the Oil Lock Piece at the bottom of the Stanchion Tube compresses the Top Out Spring, which in turn pulls upward on the Cartridge Tube. Pulling the Cartridge Tube upward causes it to pull upward on the Compression Valve Body via the Internal Circlip (again, not shown--sorry!) that holds the Compression Valve Body into the Cartridge Tube. If you're very lucky, and put enough tension on the fork assembly, enough friction will be generated between the Compression Valve Body and the Internal Circlip to stop the Compression Valve Body from spinning freely, and then you can remove the Bottom Bolt.

2. Forget everything I've written above and get yourself a long 6mm Allen bit and an air wrench. Not an impact driver; not an electric hammer drill; an air wrench. Carefully and fully seat the Allen bit into the head of the Bottom Bolt and BRRRRRRRRRAAAAAAAAAAPPPPPP--it'll be out in less than a second.

Ciao,

...and once you do get it out and complete the service, continue to service it on a regular basis do you or the next guy don't go through the same crap again.

JZH

2. Forget everything I've written above and get yourself a long 6mm Allen bit and an air wrench. Not an impact driver; not an electric hammer drill; an air wrench. Carefully and fully seat the Allen bit into the head of the Bottom Bolt and BRRRRRRRRRAAAAAAAAAAPPPPPP--it'll be out in less than a second.

Ciao,

Thanks for the great post JZH. I did try pulling on it, but it's a bit awkward so I'll try that again with a helper. But regarding the air wrench - how is this different than a simple cordless drill? Not an impact or hammer cordless, just a regular drill motor. Cause I've had no luck with that.

I'm 99% sure that the compression valve is spinning inside of the cartridge as you say.

SEBSPEED

...and once you do get it out and complete the service, continue to service it on a regular basis do you or the next guy don't go through the same crap again.

Bike only has 12,000 miles on it. Fork oil doesn't even smell. Right fork bolt came out fine.

joeystalin

Beck

Showa had been building forks of such design for ages and Honda never found it neccesary to request for any changes all those years to make it easy for the home mechanic to remove that lower bolt........ I guess Honda Motor Corporation just assumes all buyers of their bikes just go to their dealership service departments for everything that needs servicing on their bikes. I suspect service departments will be quite ticked off if all the "special tool" notations on the Honda Service manuals dissapear too....... Customers, what the hell do they know anyway........blehhhh.

I was going to suggest a special tool to do this job. This doesn't even have the option for a special tool!

I shaved down the end of some wood round stock I had and stuck it between the end of the cartridge and the inside wall, ala Conedodger. When I turn the socket head screw, I don't see the cartridge rotating inside the fork anymore. And yet, the bolt doesn't come out. Last option is an impact or I throw this bike in the trash.

Problem is, for most of us, an air impact wrench, which pretty much is universally known as the best tool to use to remove these bolts, qualifies as a special tool..... Last time I looked in my tool boxes, I sure did not have one, same with an air compressor needed to run one......

Air impact wrench delivers hammer blows that overcome slipping parts and then spin it out pronto. Much more effective than an electric impact wrench, or drill.Worth it to buy one or track one down.

GL

Jeff

As I have had this issue a few times and I must say it is extremely easy to drill out the head of the allen bolt and replace.....Much more efficient then running around trying things :wink: I realized this on the second set of forks I had to put on :unsure:

Good Luck

V-FORE

As I have had this issue a few times and I must say it is extremely easy to drill out the head of the allen bolt and replace.....Much more efficient then running around trying things :wink: I realized this on the second set of forks I had to put on :unsure:

Good Luck

In the case of the 750 forks, we had no choice but to drill out the head. Oddly, once the head of the bolt was removed and we got the forks apart, the remainder of the bolt unscrewed by hand! Telling me that the bolt was somehow seized to the fork slider.

The only thing that has worked for me without fail is an 1/2" drive air impact wrench. And used before the legs are disassembled i.e., the springs removed.

BBBBBBBRRRRRRRRRRRRRAAAAAAAAAAAPPPPPPPPPPPPPPPP

[image: post-8974-0-86225700-1380873004.jpg]

All very interesting stuff gents. I'm thinking about getting Jamie D to send me one of his modified CBR929 shocks and valves/springs for the forks. This is exactly what I need to know for a problem I could face with the forks. Very nice to know what to look out for in advance!

Before I had my own air wrench, I used to drop by one of the local bike shops with my forks in hand. Like I said, it takes just a few seconds to do it using the proper tool, so I don't think I ever had to pay.

Btw, I would never try to do this with the forks still on the bike. It doesn't take much effort to remove the forks, and given that the bottom bolts are special, shallow head Allens (to clear the thick side of the axle), they are very easy to strip out. You also cannot really clean the forks properly without removing them.

Ciao,

Bolt came out yesterday at work with....an impact wrench. I was almost hoping it wouldn't work so that everyone would agree with me that its a shitty design and we would all march together to Showa's doorsteps with pickaxes and torches and demand a redesign. Instead I guess I'll just continue rebuilding my shocks. Thanks everyone!

Excellent news!

Ah, but we all still agree that it's a shitty design. :beer:

She strikes again - trying to put the forks back together without an impact. Compression valve assembly just spinning inside the tube. Guess I'll take it back to work and try an impact again.

Question for those in the know: What would happen if I machined a retaining screw or two through the cartridge tube and into the aluminum portion of the compression valve assembly, to keep it from spinning inside of the cartridge? a small 2-56 machine screw would probably do it.

I see this in my shop from time to time. There is some finesse that can be used, but that is a learned skill. Once the bolt just spins you often have to drill it out.

On reinstall you need to chase the M8 threads on the compression base holder or you will run into exactly what you found - the screw won't go back in. Normally you can impact it back out and start over.

A word of advice: go ahead and remove the forks from the motorcycle. It take 5 minutes and saves a lot of grief.

Air impact wrench for removal and install.. As always run a tap and dye over male and female threads to clean them up before reassembly.

Been there, done that.

joeystalin

She strikes again - trying to put the forks back together without an impact. Compression valve assembly just spinning inside the tube. Guess I'll take it back to work and try an impact again.

Question for those in the know: What would happen if I machined a retaining screw or two through the cartridge tube and into the aluminum portion of the compression valve assembly, to keep it from spinning inside of the cartridge? a small 2-56 machine screw would probably do it.

I'm wondering if one can instead, add something like a "star washer" where the cartridge contacts the bottom of the fork tube and the allen bolt goes through..... Would that grip the cartridge tube end enough to keep it from spinning when you initially turn the allen head bolt to loosen it?.....

Beck

I'm wondering if one can instead, add something like a "star washer" where the cartridge contacts the bottom of the fork tube and the allen bolt goes through..... Would that grip the cartridge tube end enough to keep it from spinning when you initially turn the allen head bolt to loosen it?.....

Wouldn't that push on the damping shims, potentially causing the fork to hydraulic lock?

joeystalin

She strikes again - trying to put the forks back together without an impact. Compression valve assembly just spinning inside the tube. Guess I'll take it back to work and try an impact again.

Question for those in the know: What would happen if I machined a retaining screw or two through the cartridge tube and into the aluminum portion of the compression valve assembly, to keep it from spinning inside of the cartridge? a small 2-56 machine screw would probably do it.

Sorry, if I knew why it was engineered the way it was, I might have a more definitive answer...but I don't really see why the compression valve body has to be free to spin. Your solution might just work--or it might have serious unintended consequences!

I don't have a cartridge assembly to hand, but I think the valve body is recessed within the cartridge, which would not allow a single lockwasher to function. Maybe a stack of them? There is also the alloy cap-thing that the bottom of the cartridge sits in, so both would have to be immobilised by lock washers, methinks...

Ciao,

If it didn't damage anything, then the whole cartridge would spin. So you would need to make another tool to hold that in place. The big question would be whether the cartridge would handle the radial force without deforming.

Maybe if you find some cheap forks to experiment on it would be worth looking into. Or just a cartridge for that matter. I would think a pin would do the job just as well, as that small of a thread in aluminum may not be the best idea. With a pin, the oil cap would keep it from coming out.

YoshiHNS

If it didn't damage anything, then the whole cartridge would spin. So you would need to make another tool to hold that in place. The big question would be whether the cartridge would handle the radial force without deforming.

Maybe if you find some cheap forks to experiment on it would be worth looking into. Or just a cartridge for that matter. I would think a pin would do the job just as well, as that small of a thread in aluminum may not be the best idea. With a pin, the oil cap would keep it from coming out.

I would think that a simple woodruff key would be better than both those options. A pin would be horrible to remove for service. Especially one that has been neglected.

Key could be held in place by the oil lock (aluminum cap) and would be easy to place & remove.

rant on...

Honestly, I haven't had this issue. I think the root of this issue is having the right tools for the job. Showa doesn't expect anyone to service these forks with less than adequate tools, just as Honda would not expect someone to rebuild an engine with a flathead screwdriver and a crescent wrench.

Right tool for the job is KEY. A fork service at the dealer would cost what, $225-300? Fork rebuild parts purchased locally would cost about $80-100? So what is the big deal about using some of that $115 savings to buy a $65 rechargeable impact gun? Immediate return on investment is not always easy to come by, this is a no-brainer to me.

Of course we could write a letter to Showa and see if they will build us some forks that come apart with a butter knife. Bet that would go over well...

/rant

In short.. air impact wrench/gun... has always worked for me... and I used to do it the hard way inventing all sorts of gizmos to keep the thing from turning from the top... but the air impact gun (the one they use to remove wheel lug nuts) work a treat...

Auspañol

In short.. air impact wrench/gun... has always worked for me... and I used to do it the hard way inventing all sorts of gizmos to keep the thing from turning from the top... but the air impact gun (the one they use to remove wheel lug nuts) work a treat...

That doesn't always work - FYI

I use a 4-5" 6mm hex on a 3/8" drive to a 1/2" drive adapter on m y 1/2" air gun while the fork is still on the bike. I have yet to have one argue with me

I got really lucky with the F3 forks. Just used a breaker bar with a mallet with the forks still on the bike. Next time I'm going to just move the forks up the triples and squeeze the impact in.

IIRC, electric impact guns have been said to be insufficient for removing the bottom bolt. Just wondering if that's meant to be battery impact wrenches, impact drivers (the ones that are really only screwdrivers), or do the corded impact wrenches (capable of 200+Nm) also fall into the "not good enough" category?

My corded 1/2" impact wrench is capable of 230Nm and it will undo a properly torqued rear wheel nut in less than a second, without trying to rip itself out of my hands (ie: it is a true impact gun). The only difference between it and an air impact gun that I can tell is the noise of the electric motor. The impact hammers in it sound no different to an air tool.

Any comments/advice?

Personally I don't see any difference between a quality electric impact and a good air impact. They should both work equally as well. JMO of course. The only thing would be if the electric impact didn't hit as quickly as the air. I think that would make a difference.

I've had to use my air impact gun but with the fork mounted upside down in my woodworking vise, clamped on the caliper mount, then a floor jack to compress the fork and create spring compression to break the bolt loose. You all have been there, a 20 year old bike that's never been serviced. Those bolts can test your sanity.

Yes, so much so that I've been forced to charge for this repair. They either come out or they don't - and when not it must be drilled out. The cost of the new bolt is not a big deal, it's the time it takes. Painful!

vfrcapn

Those bolts can test your sanity.

Aren't allen heads grade 5 ?

I've drilled out 2 and they went like butter.

The annoying thing is, after you drill them out the remainder spins freely out of the valve body. Which tells me the bolt was over torqued and/or seized via the crush washer.

SEBSPEED

I've drilled out 2 and they went like butter.

The annoying thing is, after you drill them out the remainder spins freely out of the valve body. Which tells me the bolt was over torqued and/or seized via the crush washer.

Got it Seb. I recently change the fuel pump on 1996 Toyota Tacoma(352,000 miles) and choose to remove the bed instead of dropping the gas tank. 6 bolts and 2 of them had rusted to washer and then the washer also had rusted to the frame, Yeh you guess it snap the heads right off when the air impact started so drilled and replaced with some Allen Heads.

JamieDaugherty

Auspañol

In short.. air impact wrench/gun... has always worked for me... and I used to do it the hard way inventing all sorts of gizmos to keep the thing from turning from the top... but the air impact gun (the one they use to remove wheel lug nuts) work a treat...

That doesn't always work - FYI

Don't I know it!!! Today, my left fork's bottom bolt came out easily, but my right fork's bottom bolt just kept spinning (even with the impact gun). I tried compressing the fork, but no luck. But then I remembered something Jamie said... The cartridge needs to be put into tension (not compression).

Why? Because putting the cartridge into tension will hold the compression valve hard against the snap ring at the bottom of the cartridge. This gives the best chance of it staying put, and not spinning. So, this is what I did:

Pushed the stancheon into the slider as far as it would go.

Put in a stock spring (I wasn't about to put one of my new springs at potential risk).

Put in the spring retainer, so I could put force through the spring, into the damping rod.

Put a small screwdriver through the spring, then rotated it so it went toward the stancheon. When it reached the stancheon, I kept rotating it to load the spring, putting the cartridge into tension.

At first, I tried to turn the bottom bolt with a ratchet, but the compression valve still spun.

Then I put the impact gun onto it again... Zip twang! Bolt undone, and then all I had to do was find the spring retainer that had disappeared into a darkened corner of the garage...

In the future, If I need to do it again, I'll put a towel over the end of the damping rod, so it won't flick out.

Here's a photo (after I got the bolt out) showing the basics of what I did:

[image: post-28511-13859001010002.jpg]

I hope this helps someone from needing to drill out the bolt head one day. :D

:cheerleader: :cheerleader: :cheerleader: :cheerleader:

Some additional info about the spinning bolt situation that I had:

Before I pulled the forks apart, I noticed that the RH leg (the spinning one) had the bolt countersunk more than the other one. Now that I come to re-assemble it, I find that the sealing washer is missing! Both legs had some sealant goo in the bottom. I'd say that the goo is probably a production solution to leaking forks in the event that the washer is missing. The missing washer means that the bolt sticks up into the comp valve a bit further than it should - into the area where the thread isn't formed so well, at the end of the M8x1.25 thread. This causes the bolt to have more friction than it normally would, resulting in it loosening only a bit with the impact gun, then spinning the comp valve.

Moral of the story: Don't forget to put in the sealing washer!

So you basically need to PULL on the spring with the top end retained or connected to the damping rod via the retainer washer acting as a stopper?

Auspañol

So you basically need to PULL on the spring with the top end retained or connected to the damping rod via the retainer washer acting as a stopper?

You need to pull the damping rod into the fully extended position at the same time as pulling the fork's lower outer tube in the opposite direction.

Dannytb

Don't I know it!!! Today, my left fork's bottom bolt came out easily, but my right fork's bottom bolt just kept spinning (even with the impact gun). I tried compressing the fork, but no luck. But then I remembered something Jamie said... The cartridge needs to be put into tension (not compression).

Why didn't I think of that? :wink:

Ciao,

I had some problems to. Tried to drill the allen bolt out but it took ages. Maybe because of bad drills.

So I bought a simple corded electric impact wrench with the specs 200w/500nm/6000rpm and it worked well!

An air supported impact wrench rocks but an electric alternative may work!

Skickat från min iPhone med Tapatalk

Hi,

Mine are also seized- before I drill them out or attempt to remove does anyone know the size and length of the bolts? I believe they are a M8 but not sure how long.

Thanks

wagzhp

Put the springs back in and put the top cap back on, and hit it with an impact wrench. Hopefully having the internals in place will put enough tension on the cartridge to allow the impact wrench to back the screw out.

Yep, this is what you do. it's the instant hit with the impact and the extra tension when all it's still all together that makes this happen.