Replacing fork bushings

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Thanks, Auburn. I'll keep that in mind in the future.
I know that the red is pretty tenacious stuff, and that you have to use heat to release it. I try not to use the red stuff on anything that isn't a permanent connection, that I want to disassemble nondestructively in the future.

Plus I've never got in the habit if just slathering everything with loctite, just because. If it doesn't specifically call for it in the service manual I don't use it. And as you pointed out, it doesn't call for it on the Allen bolt that holds the cartridge in the lower fork leg.
I should clarify, it is the Honda red locktite (not sure if it equates to red Locktite brand or not) It is not supposed to need heat to remove.

 
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The threadlocker symbol is shown on the fork internal parts diagram in both the '03 and '06 Yamaha Service Manuals that I have.
An arrow from the symbol is pointing to the damper rod bolt.

Maybe it's an error but it appeared in at least two manuals three years apart.
Good catch. The FSM does say to use loctite on that bolt, and to replace the copper sealing washer each time.

Searching through the manual I can't find which specific form of loctite they want you to use, but I would suspect they mean the blue 242 threadlocker, which is medium strength and should not require heat to release it.

Here's the spiel for the 242 from Loctite's web site:

Loctite Threadlocker Blue 242 is designed for the locking and sealing of threaded fasteners which require normal disassembly with standard hand tools. The product cures when confined in the absence of air between close fitting metal surfaces. It protects threads from rust and corrosion and prevents loosening from shock and vibration. Loctite® Threadlocker Blue 242 is particularly suited for applications on less active substrates such as stainless steel and plated surfaces, where disassembly is required for servicing.
 
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One or two more questions before I attempt this. I'll be installing new bushings too.

Does the upper bushing need to be driven down any lower than what the washer above it requires? Is there supposed to be some space between the upper edge of the bushing and the washer?

Is it OK to drive the upper bushing down as far as possible with the PVC pipe and then stack the old removed bushing atop the new bushing and then drive the new bushing down a bit farther to its final position?

I assume if I did this I could easily remove the old bushing before installing the washer.

Finally is it acceptable to use a crescent wrench rather than an open end wrench to loosen and tighten the cap bolt up top? I don't have a 24 mm open end wrench. Don't see all that much difference between an open end wrench and a crescent wrench. Both only interface with two of the six sides of the head or nut. Also, I don't have a 17 mm open end wrench for adjusting the spring preload up top. As I recall I used a crescent here too to make adjustments.

 
When you drive the upper bushing into the lower fork leg you will want to drive it as far in as it will go. You'll be able to feel the difference when it is down all the way. Yes, you can (and should) use the old upper bushing to drive the new one in the last bit. When it is all the way in the upper edge of the bushing will be slightly below the upper edge of the bore in the leg. That upper edge of the fork leg is chamfered a bit and the bushing will be below the chamfering. Then the washer goes on and the seal pressed in all the way. You'll know the seal is far enough when you can get the expansion clip back into the groove above the seal.

 
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When you drive the upper bushing into the lower fork leg you will want to drive it as far in as it will go. You'll be able to feel the difference when it is down all the way.
You can hear the difference as you drive it in. It goes from sounding loose as you drive it down and changes tone to sound really solid like you are pounding on the fork leg directly.

One or two more questions before I attempt this. I'll be installing new bushings too.
Does the upper bushing need to be driven down any lower than what the washer above it requires? Is there supposed to be some space between the upper edge of the bushing and the washer?

Is it OK to drive the upper bushing down as far as possible with the PVC pipe and then stack the old removed bushing atop the new bushing and then drive the new bushing down a bit farther to its final position?

I assume if I did this I could easily remove the old bushing before installing the washer.

Finally is it acceptable to use a crescent wrench rather than an open end wrench to loosen and tighten the cap bolt up top? I don't have a 24 mm open end wrench. Don't see all that much difference between an open end wrench and a crescent wrench. Both only interface with two of the six sides of the head or nut. Also, I don't have a 17 mm open end wrench for adjusting the spring preload up top. As I recall I used a crescent here too to make adjustments.
I use the metal pipe to drive the bushing in place as it fits over your upper fork tube, but is thinner than the bushing so it doesn't hit the lower fork tube. I use it like a slide hammer to drive the bushing in place. It does take some force to drive it down.

Be careful with the crescent wrench so that it fits snugly and you don't round off the hex on the cap. Might be worth a trip to get a 24mm box end wrench from Lowes or harbor freight. The caps are really soft and it is easy the round them. The 17 mm crescent wrench may not be thin enough to fit securely on the preload adjuster, but there is a lot less force need to turn that then the 24mm fork cap.

 
I would not trust a cresent wrench to this task.

Either the closed end of a combination wrench, or a 6-point socket.

 
OK, thanks. That 24 mm nut is quite shallow, certainly not as robust as a standard 24 mm steel nut.

After looking at it a bit more I'll just use a 24 mm socket to loosen and tighten the cap bolt. I have this socket in my kit, although a 12 point one. According to the manual the cap bolt is not all that tight at 18 lbf-ft.

My bike is almost 14 years old. Not terribly concerned about aesthetics at this point. I can always use a pipe wrench!

I'm too cheap to buy a new wrench for this application. But I'll check my local vendor of Chinese tools and see if they offer 24 mm and 17 mm combination wrenches for a few dollars. Box end wrenches are typically 12 point, aren't they?

Got lots of wrenches just not the two I need in this situation.

I won't loosen the cap bolt until I drop the inner tube down a bit below the upper steering head bracket. One pinch bolt in the lower bracket should hold the tube while I loosen the cap bolt with the socket. I'll stabilize the tube with my left hand and wrench with my right. I shouldn't damage the lower bracket if I'm careful.

Looks like you are almost forced to use an open end wrench to adjust the spring preload unless you remove the black plastic knob. The knob appears to have a larger diameter than the preload nut so a closed end wrench is out.

Should be fun! Gotta change the front tire and some brake pads too! May be time for new brake fluid also.

My dealer in Alabama says he just replaces the fluid in the MC reservoir periodically. Doesn't remove at the calipers. Just trying to reduce the moisture content of the fluid. The water in the old fluid quickly disperses throughout the new fluid leaving a lower overall moisture content. That's the goal. Raise the boiling point and prevent corrosion.

 
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OK, thanks. That 24 mm nut is quite shallow, certainly not as robust as a standard 24 mm steel nut.
After looking at it a bit more I'll just use a 24 mm socket to loosen and tighten the cap bolt. I have this socket in my kit, although a 12 point one. According to the manual the cap bolt is not all that tight at 18 lbf-ft.

My bike is almost 14 years old. Not terribly concerned about aesthetics at this point. I can always use a pipe wrench!

I'm too cheap to buy a new wrench for this application. But I'll check my local vendor of Chinese tools and see if they offer 24 mm and 17 mm combination wrenches for a few dollars. Box end wrenches are typically 12 point, aren't they?

Got lots of wrenches just not the two I need in this situation.

I won't loosen the cap bolt until I drop the inner tube down a bit below the upper steering head bracket. One pinch bolt in the lower bracket should hold the tube while I loosen the cap bolt with the socket. I'll stabilize the tube with my left hand and wrench with my right. I shouldn't damage the lower bracket if I'm careful.

Looks like you are almost forced to use an open end wrench to adjust the spring preload unless you remove the black plastic knob. The knob appears to have a larger diameter than the preload nut so a closed end wrench is out.

Should be fun! Gotta change the front tire and some brake pads too! May be time for new brake fluid also.

My dealer in Alabama says he just replaces the fluid in the MC reservoir periodically. Doesn't remove at the calipers. Just trying to reduce the moisture content of the fluid. The water in the old fluid quickly disperses throughout the new fluid leaving a lower overall moisture content. That's the goal. Raise the boiling point and prevent corrosion.
yes correct on the 17mm to adjust, Doesn't take much force to adjust.

Might put out a call and see if anyone else on the forum lives near you that might have the tools you need as well as a vacuum pump for doing brakes. You can also can do the fluid the old fashioned way, by replacing the fluid in the reservoir and pump the brake lever holding the pressure on while cracking open the bleeder on the brake caliper, and closing before the lever reaches the handlebar so it stays under pressure. Then pump the lever again to get a full lever and repeat again. Do this until you get clean clear fluid. Get a short piece of clear tubing to fit over the bleeder so you can drain into catch bottle. Brake fluid is very harsh on paint.

Best to do this with two people. Takes a little longer, but is very effective.

 
Red loctite requires over 600 degree F to release. That's pretty dam hot. Blue loctite would be better suited. A lot of our medical instruments get red loctite in use. We have to heat the shit out of them to get them apart. We have a hand held induction coil to heat things up in a local area and works great. They aren't cheap but are nice to have.

Dave

 
I would not recommend waiting to loosen the fork cap. You should break it loose (both sides) as the very first step of this project (right after putting the bike on the center stand). Rotate the handlebars all the way to the left so that you can push against the handlebar stop. You might consider soliciting a helper to just hold the handlebars against the stop while you break the cap loose. I do that because it makes me feel better about not wobbling the bike so violently that I would knock it off the center stand.

Once the fork tubes are out of the bike, you can push down on the cap while you loosen it by hand. When the last thread on the cap finally gives, the fork spring will want to push the cap up. Its not enough spring pressure to launch the cap to the ceiling, but if you are not prepared for it, it can surprise you. Keep the palm of your hand over the cap the whole time you are loosening it. Don't put your face within 12" of the fork cap as you are loosening it. Then you will be fine.

Hope this makes sense.

 
Actually, after you get the bike on the centerstand you need to loosen the top clamp pinch bolts BEFORE attempting to loosen the cap. If you don't, there is a very good chance that you will trash the threads on the cap.

 
That has not been my experience. The "line" that forms between the cap and the upper fork tube has always been exposed just (and I mean JUST) above the top of the triple clamp. But if by some chance that line is below the T/C, I agree - loosen that bolt first.

 
Actually, after you get the bike on the centerstand you need to loosen the top clamp pinch bolts BEFORE attempting to loosen the cap. If you don't, there is a very good chance that you will trash the threads on the cap.
it depends on where your forks are set at. If the line between the fork tub and cap is showing above the triple clamp, then the caps will break free. If the caps are even with the top of the triple clamp, then you are correct and need to loosen the top clamp so the cap can turn.

Only had once instance where the cap was even with the top of the triple clamp in all of the forks I have done.

 
In the last few days I replaced the front tire, two of the front brake pads, fork oil seals, dust seals, tube bushings, and fork oil.

Several hours cumulative working alone.

One of the four bushings was worn a bit -- the left inner tube bushing. The other three appeared like new after 88K miles.

One of the oil seals had been leaking but I couldn't see any blemish on it. Don't know why it leaked.

I have never disassembled forks before so a new experience. I had replaced the oil once but had never taken the forks completely apart.

I had to fashion some crude tools to do it.

The first was a wire hook to remove the washer atop the damper rod assembly. The one at the bottom of the spring. I noticed they deleted this washer on the '06 model. Good decision! They made the spring diameter smaller at the bottom. No more need for a washer seat.

I made a tool to hold the damper rod assembly while removing/installing the bottom bolt. I'm not a welder so I looked for an alternative to a socket tool. I don't have an impact wrench which may be the best option. If you use an impact tool you may not have to remove the spring lower washer during disassembly. That would be good. I chose to use two short pieces of pvc pipe instead.

A 1" pipe can be easily modified to grab onto the 26 mm nut on the damper rod assembly. I beveled the inside edge a bit with a dremel to ease the connection to the nut. I made three cuts on the pipe end with a hacksaw spaced 60 degrees apart for the six points of the hex nut. With these mods the pipe would grab the nut but wouldn't hold it securely without some "shoving in" force being applied. Since I was working alone I couldn't adequately apply this force. So I used a second pvc pipe too.

I used a 1-1/4" pipe a bit shorter than the 1" pipe. A 1" pipe fits very nicely inside a 1-1/4" pipe. A 1-1/4" pipe fits snugly inside the 48 mm fork tube.

Okay. I first slid the 1-1/4" pipe into the fork tube with the end just beyond the hex nut on the damper rod assembly. Then, I slid the 1" pipe in and maneuvered the end onto the hex nut. Finally I took a wood block and drove the 1" pipe solidly onto the nut. The pipe tabs I made with the hacksaw bent out ever so slightly until they tightly contacted the 1-1/4" pipe. The resulting pipe sandwich gripped the nut like a socket. No end force on the pipes was necessary now. I grabbed one of the pipes with a small pipe wrench and held fast while I broke loose and removed the bolt with a ratchet.

The small pipe was helpful when re-installing the damper rod assembly and bolt too.

Finally, I used pvc in installing the outer tube bushing and oil seal. A 1-1/2" pvc pipe coupling fits closely around the inner tube. You have to remove a small junction inside the coupling at the center-line but that's very easy with the dremel. This makes good contact with the edge of the outer tube bushing. I drove the bushing down flush using the coupling then stacked the old, removed bushing atop the new bushing and then drove the new bushing down to its final position. I pressed the oil seal into position using a short piece of 2" pvc pipe. I used the 2" pipe in the installation of the bushing too.

Working alone one has to improvise!

Seeing the internals of the forks I now understand how it all works. I didn't realize the small spring on the outside of the damper rod assembly limits how far the fork will extend. Nor did I realize that the oil flow stopper installed at the bottom of the damper rod assembly limits how far the fork can compress. I'm not sure if the fork spring actually stops compression before the inner tube makes contact with the stopper.

All in all a good learning experience.

 
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I'm not proficient at getting photos onto this forum. I don't have an account on a server to do this. Maybe there's a free one available.

The pinching of the lower bracket about the tubes is a bit of a mystery. I used a torque wrench to tighten the pinch bolts so they all should have been equal. I tightened them in stages since there are two in parallel.

Yet the remaining pinch gap on one tube was visibly different from the other. One gap was obviously wider than the other. Must have always been that way. Just hadn't noticed it. I assume both tubes have identical circumferences. No chance for tube misalignment.

Had to remove the horns to get my torque wrench down to the lower pinch bolts. Easy except for fumbling with the two electrical connectors. Hope the polarity isn't important on horns! Seem to work OK.

On the first fork the copper washer stayed on the outer tube. It never came off. On the second the washer came off with the bolt.

Sawed off an ell-shaped 8 mm hex wrench I'd never used so that I could use it with my torque wrench. I've got an 8 mm hex bit socket but it's not long enough to reach the fork bolts. Hex wrenches are made from tough stuff!

Aside --

Whenever you're removing the front tire I'd recommend putting a 2 x 8 chunk of lumber under the center-stand for added elevation. That extra bit of height offers welcomed clearance between tire and fender.

 
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My pvc tools are:

1" pipe with six equally spaced cuts on one end and six equally spaced internal grooves on the other end.

1-1/4" pipe

1-1/2" coupling with center-line stop removed

2" pipe

You can see on the 1" pipe where the six points of the hex nut have deformed the plastic.

https://imgur.com/dwmcJrU

1" pipe inserted into 1-1/4" pipe. This is the configuration for locking onto the hex nut. 1-1/4" pipe extends out over the end of the smaller pipe limiting how far the six cut tabs can bend out when driven onto the nut.

https://imgur.com/lfLLSaR

Other end of 1" pipe. I cut some small grooves for the re-installation of the damper rod assembly. Don't need much gripping ability here. Just enough to get bolt snug. Pipe not required for final torquing. Wanted to ensure that no plastic bits were left in fork. Cut grooves with a triangular cross-section file using the three abrasive edges.

https://imgur.com/IRkunCs

 
I wonder if the wear on the bushings correlates with front brake pad wear?

Would imagine the bushings are loaded most when braking hard. The forks compress and a lot of force is applied to the front of the outer tube. The loading would be significant particularly on the inner tube bushing which has a larger surface area.

Would imagine riders who quickly go through brake pads would also experience significant bushing wear.

In 88K miles I had previously only replaced two front brake pads. I replaced the other two fronts last week. I brake like a granny!

 
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