FRONT FORKS DISASSEMBLY (A few helpful hints)

FRONT FORKS DISASSEMBLY (A few helpful hints)

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  • On 19th August 2015

Things don’t always go according to plan, do they?  And when they don’t, frustration is the most common and inevitable outcome.  The seemingly simpler the task and the more we fail in performing it the greater the resulting frustration.  Like trying to unscrew a screw that just won’t budge.  It can lead to rage.

There is a very good and instructive video on youtube about HONDA CB550 front forks disassembly and reassembly.  Like all videos on you tube, this one, too, shows a procedure in which everything goes according to plan.  But what if the screw at the bottom of the slider, which must be unscrewed in order for everything to come apart, didn’t come loose?  What then? The fork tubes cannot come out and if the fork tubes didn’t come out, the oil seals could not be removed and replaced.  So, it is crucial to remove that damn screw!

Here is a close-up of it:

View of bolt head

In ultimate frustration, people report resorting to extraordinary measures like heating the screw to the point of melting, drilling it out, using broomsticks, etcetera, etcetera.

Frustration is often a result of failure.  And failure is often the result of ignorance or lack of skill (or also just as often the lack of having the right tool) or all of the above.

Knowing how things work and why they were designed the way they were designed is the key to keeping cool.

The bolt in question, sometimes referred to as “8 mm bolt” or “oil lock bolt” or “Allen bolt” (see item 12 in the drawing below),  screws into what the HONDA manual calls “bottom pipe” (item 6 in the same drawing).

FRONT FORK COMPONENTS CB550

I know, I hear you.  And I agree.  It takes a genius or a lot of experience or, at a minimum, an engineering degree to take a quick look at the above drawing and say, “Yeah, sure, item #12 screws into item #6”.

The “bottom pipe” looks like this:

Bottom pipe view

And here is a view of the bolt screwed into it:

View of bolt screwed into bottom pipe

So, if you can grab hold of the bottom pipe somehow, unscrewing the oil lock bolt should be a piece of cake.  Those who took the time to examine the bottom pipe in detail would notice that there is a pin running from end to end at the very top of it, which looks like this:

View of pin at top of bottom bolt

The curious might even ask the question, “Why is this pin there?  What does it do?”  I personally don’t know.  But I would like to think that the designers put it there for a reason.  I like to think that all designers, HONDA designers from the 1970’s in particular, don’t put extra things in the parts they design for no reason.  Additional “things” increase the complexity, which, in turn, increases the cost.

I’m tempted to assume that this pin in the bottom pipe is there so if the oil lock bolt, made infamous in hundreds of reports in all forums on the web, fails to come unscrewed, a simple tool can be inserted into the fork tube to engage that pin and provide all the needed support to prevent the bottom pipe from spinning, and, thus, allowing for an easy removal of the bolt.  So, if the screw fails to come loose, “keep calm and carry on”. Unscrew the front fork bolt (item #2 in the drawing above) and remove the spring.  Now you will have a direct unrestricted access to the top of the bottom pipe. Insert something that could engage the pin in the bottom pipe (a long flat screwdriver or a small diameter pipe with the right cut in it, or a broomstick if you must) and the rest should be easy.

A few more helpful hints:

1.  The new seals you may have ordered from HONDA (part # 91255-KBH-003) might look different from the seal you removed from your forks.  That’s OK.  The seal designed changed.

2.  The new design seal should be installed with the ID information embossed on the periphery of the seal facing out (upwards).

3. An easy (and the cheapest) way to install the new seal is to use the old seal as a drive tool.  Just place the old seal on top of the new one and carefully hammer the new seal in until it stops and sits square.

I hope this helps.

QUESTIONS?