Author Topic: Disassembling front forks - K1 750  (Read 2259 times)

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Online ZTatZAU

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Disassembling front forks - K1 750
« on: January 19, 2024, 12:56:39 PM »
I'm in the process of disassembling my K1 750's front end to rebuild the forks with new fork seals and booties, install a new steering stem/lower bridge and replace the original ball steering bearings with an All Balls tapered bearing set.  I've never done any of this before!

I've removed the front wheel, (+ the fender), and caliper... and loosened the upper and lower fork pipe bolts as described in the FSM.

1) Is there anything else that needs to be done before I... "Pull the fork(s) 'gentle' out the bottom." ?

2)  I've released the top end of the original booties but can the chrome top bolts (filler caps?) remain in place and simply slide out through the triple trees/bridges?

3)  Do the fork covers and headlight assembly all remain in place until I start disassembling the steering stem?

Thanks!  ZT

Offline bryanj

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Re: Disassembling front forks - K1 750
« Reply #1 on: January 19, 2024, 01:11:51 PM »
BEFORE loosening the fonks in the trees loosen the allen key headed bolt that goes upwards from the bottom
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Offline 69cb750

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Re: Disassembling front forks - K1 750
« Reply #2 on: January 19, 2024, 01:19:13 PM »
1) Is there anything else that needs to be done before I... "Pull the fork(s) 'gentle' out the bottom." ?

Quote
2)  I've released the top end of the original booties but can the chrome top bolts (filler caps?) remain in place and simply slide out through the triple trees/bridges?
Leave chrome bolts in place they pull through the tree.

Quote
3)  Do the fork covers and headlight assembly all remain in place until I start disassembling the steering stem?
Yes, remove fork tubes, remove light brackets.

Online ZTatZAU

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Re: Disassembling front forks - K1 750
« Reply #3 on: January 19, 2024, 01:25:19 PM »
BEFORE loosening the fonks in the trees loosen the allen key headed bolt that goes upwards from the bottom

Thanks for that Brian!  I assume that's because the tree bolts will prevent the fork assembly from turning, while removing that bottom hex bolt, better than anything else after the fork is removed.  Correct?
ZT

EDIT!  WELL, it looks like it might have been better to loosen that bottom hex bolt before removing the fender... because, even with the bridge bolts tight, the bottom fork leg rotates freely on the inner fork tube.

What do you suggest now!
Thanks!  ZT
« Last Edit: January 19, 2024, 01:36:21 PM by ZTatZAU »

Online ZTatZAU

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Re: Disassembling front forks - K1 750
« Reply #4 on: January 19, 2024, 01:27:22 PM »

Leave chrome bolts in place they pull through the tree.

Yes, remove fork tubes, remove light brackets.

Thank you sir!
ZT

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Re: Disassembling front forks - K1 750
« Reply #5 on: January 19, 2024, 01:28:57 PM »
Actually the Allen head screw is into a seperate part inside the fork. Leaving every thing assembled, and the internal spring pressure inside makes it easier to remove that bolt. Get the correct size, deep reach Allen socket in there and hit it with an impact gun.

Offline Medyo Bastos

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Re: Disassembling front forks - K1 750
« Reply #6 on: January 19, 2024, 01:41:36 PM »
Actually the Allen head screw is into a seperate part inside the fork. Leaving every thing assembled, and the internal spring pressure inside makes it easier to remove that bolt. Get the correct size, deep reach Allen socket in there and hit it with an impact gun.
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Offline Tim2005

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Re: Disassembling front forks - K1 750
« Reply #7 on: January 19, 2024, 02:13:15 PM »
Leave the chrome top bolts ("fillers") in place but first tighten the lower clamp so the tube is held in place, loosen the upper clamp, then just start to undo the chrome top bolts- it's so much easier to get them loose like that instead of when they are off the bike

Online ZTatZAU

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Re: Disassembling front forks - K1 750
« Reply #8 on: January 19, 2024, 02:17:01 PM »
Actually the Allen head screw is into a seperate part inside the fork. Leaving every thing assembled, and the internal spring pressure inside makes it easier to remove that bolt. Get the correct size, deep reach Allen socket in there and hit it with an impact gun.
Thanks for your reply, John!  But, just so I'm sure, by "leaving every thing assembled"  do you mean both bridge bolts tight, fender installed... everything but the front wheel installed?

For full disclosure, I must admit that, I actually tapped one fork leg down a bit from the top bridge with a piece of wood and a mallet to where the chrome top bolt is now flush with the top of the top bridge.  Then after reading Brian's suggestion, I then retightened the bottom bridge fork bolt and tried to loosen the bottom hex bolt with a regular 6mm L shaped hex key.  The result, as you likely already surmise, was that the bottom fork leg rotated freely as I tried to loosen the hex bolt.

At this point, would you suggest I try to raise the fork leg back up to where I can reinstall the fender, retighten both bridge bolts, and hit it with a hex key socket on an impact gun?  Or just leave everything as it is, and try the impact gun while trying to hole the lower leg from turning?

I am learning and I'll know better the next time!
ZT 

Offline bryanj

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Re: Disassembling front forks - K1 750
« Reply #9 on: January 19, 2024, 03:04:44 PM »
I have in the past stopped the alloy slider rotating using an adjustable spanner, NOT A PIPEWRENCH, on the bottom of the slider where the half circle vuttout is for the axle
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Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Online ZTatZAU

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Re: Disassembling front forks - K1 750
« Reply #10 on: January 19, 2024, 03:31:34 PM »
I have in the past stopped the alloy slider rotating using an adjustable spanner, NOT A PIPEWRENCH, on the bottom of the slider where the half circle vuttout is for the axle
Thanks for the suggestion Brian!
I was thinking of drilling a couple of holes in a length of 1x4 to match the threaded fender attach holes on the bottom slider.  Then hang on to that.  But your idea would be much quicker and should work just as well... whether the fork is on or off the bike.
I'll give that a try.

I did loosen the chrome top caps as Tim2005 suggested and they broke loose quite easily by hand.  So I'm hoping the bottom hex bolts won't be as tight as I've heard others describe.  Thanks Tim!

ZT

Online denward17

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Re: Disassembling front forks - K1 750
« Reply #11 on: January 19, 2024, 03:54:43 PM »
I recently went through this on a CB550, same concept I guess.

Do you have a bench vise?  If so, you can open it wide and place wood blocks on both sides, then put your lower fork leg in between the wood and tighten down as a holder.  I used an impact driver to those pesky 8mm (6mm) allen bolts out of the bottom.
If you use a bench vise, make sure to point the lower leg fork bolt holes (brake caliper holes)  away from wood.

I actually rounded one out, that's a story I 'll save you from, but I did get it out.

Online ZTatZAU

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Re: Disassembling front forks - K1 750
« Reply #12 on: January 19, 2024, 04:39:25 PM »
I recently went through this on a CB550, same concept I guess.

Do you have a bench vise?  If so, you can open it wide and place wood blocks on both sides, then put your lower fork leg in between the wood and tighten down as a holder.  I used an impact driver to those pesky 8mm (6mm) allen bolts out of the bottom.
If you use a bench vise, make sure to point the lower leg fork bolt holes (brake caliper holes)  away from wood.

I actually rounded one out, that's a story I 'll save you from, but I did get it out.

I appreciate your reply, denward17... but in this case, it much ado about nothing.  I hunted in all the corners of the shop but couldn't find my largest crescent wrench with jaws long enough to get a good even bite on the lower sliders as Brian suggested.

So I rigged up a 20" 1x4 bolted on the inside of the lower slider with the other end braced up against the other fork leg.  I hope ya'll can picture that?

One short hit with impact hex socket and the bottom hex bolt came right out and then screwed back in by hand.  I never switched the 1x4 around to the other fork leg and just held on to it with my bare hand and the impact hex socket did the same quick job on the other side.

So I guess my hex bolts were nowhere near as tight as others have described... with or without locktite or threadseal.  It was "Easy Peasy!"

Thanks for the tutelage guys!  I'll have the forks out this evening but I don't know about coming gently out the bottom as the FSM describes.  Is it normal to have to tap them out from the top with a mallet after everything is loosened up?
ZT

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Re: Disassembling front forks - K1 750
« Reply #13 on: January 19, 2024, 04:46:53 PM »
Well done!

Perfectly normal. Does your top clamp have a “D” washer in the gap? It’s there to prevent over torquing the bolt and cracking the yoke.

Online ZTatZAU

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Re: Disassembling front forks - K1 750
« Reply #14 on: January 19, 2024, 05:35:05 PM »
Well done!

Perfectly normal. Does your top clamp have a “D” washer in the gap? It’s there to prevent over torquing the bolt and cracking the yoke.
Thanks John! 

No "D" washer that I can see in the openings on the outboard edges of the upper bridge. 
I'm just now back at it after a bite to eat.  Should I be able to see the D washer before the forks have been removed?
ZT

Online denward17

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Re: Disassembling front forks - K1 750
« Reply #15 on: January 19, 2024, 07:13:07 PM »
One of mine just about fell out, the other I had to beat it almost all the way out.

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Re: Disassembling front forks - K1 750
« Reply #16 on: January 19, 2024, 08:11:42 PM »
Well done!

Perfectly normal. Does your top clamp have a “D” washer in the gap? It’s there to prevent over torquing the bolt and cracking the yoke.
Thanks John! 

No "D" washer that I can see in the openings on the outboard edges of the upper bridge. 
I'm just now back at it after a bite to eat.  Should I be able to see the D washer before the forks have been removed?
ZT

You should be able to see them in the split. If missing, get a set.

Online ZTatZAU

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Re: Disassembling front forks - K1 750
« Reply #17 on: January 20, 2024, 08:13:57 PM »
Well done!
Perfectly normal. Does your top clamp have a “D” washer in the gap? It’s there to prevent over torquing the bolt and cracking the yoke.
Thanks John! 

No "D" washer that I can see in the openings on the outboard edges of the upper bridge. 
I'm just now back at it after a bite to eat.  Should I be able to see the D washer before the forks have been removed?
ZT

You should be able to see them in the split. If missing, get a set.
Thanks John!

Both of my forks are now out and on the bench!  And based on how nice my fork tubes looked, while still on the bike when I first pulled the booties down from the fork covers, I was quite surprised at how much rust I saw on the upper portion of the fork tubes between the upper and lower triple trees, once I got them out.  Is it typical to find a significant amount of rust on the top 8" - 9" of the fork tubes that are normally hidden by the fork covers?

There were no D washers in my top bridge!  But I did look them up in my Honda parts manual and your description above fully explains why it's a good idea to have them in there.  Do you happen to know if they are still available from Honda or do you normally cobble the D shape out of plain washers?  If the latter can you tell me how thick the OEM D shape washers were?

I'm also wondering if there is some trick, (other than a utility knife), to release the lower end of the booties from the brushed aluminum lower sliders.  I've warmed them up with a heat gun but still can't seem to slide anything in under the rubber lip to remove them.

I do appreciate all your helpful replies!  ZT

Offline The Lone Builder

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Re: Disassembling front forks - K1 750
« Reply #18 on: January 21, 2024, 12:57:48 AM »
You mean like this?

Whilst it looks awful, this rust is not important in terms of function; the important part of the stanchion is the bit that slides in and out of of the lower leg.
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Offline The Lone Builder

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Re: Disassembling front forks - K1 750
« Reply #19 on: January 21, 2024, 01:17:40 AM »
Well done!
Perfectly normal. Does your top clamp have a “D” washer in the gap? It’s there to prevent over torquing the bolt and cracking the yoke.
Thanks John! 

No "D" washer that I can see in the openings on the outboard edges of the upper bridge. 
I'm just now back at it after a bite to eat.  Should I be able to see the D washer before the forks have been removed?
ZT

You should be able to see them in the split. If missing, get a set.
Thanks John!

Both of my forks are now out and on the bench!  And based on how nice my fork tubes looked, while still on the bike when I first pulled the booties down from the fork covers, I was quite surprised at how much rust I saw on the upper portion of the fork tubes between the upper and lower triple trees, once I got them out.  Is it typical to find a significant amount of rust on the top 8" - 9" of the fork tubes that are normally hidden by the fork covers?

There were no D washers in my top bridge!  But I did look them up in my Honda parts manual and your description above fully explains why it's a good idea to have them in there.  Do you happen to know if they are still available from Honda or do you normally cobble the D shape out of plain washers?  If the latter can you tell me how thick the OEM D shape washers were?

I'm also wondering if there is some trick, (other than a utility knife), to release the lower end of the booties from the brushed aluminum lower sliders.  I've warmed them up with a heat gun but still can't seem to slide anything in under the rubber lip to remove them.
If you look at the parts book, Item no 20 rotates a bit and when you turn it the boot is free(er) to come out.

When I did my forks I struggled to find a diagram of what I found inside; then I cam across this in an old issue of Classic Motorcycle Mechanics. Maybe it'll help.

I do appreciate all your helpful replies!  ZT
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Re: Disassembling front forks - K1 750
« Reply #20 on: January 21, 2024, 05:58:12 AM »
Check out page two of the FOR SALE Section. “Johnie” sells them.

Those rubber boots are just stuck. Shouldn’t be glued.

The rust at the top is totally typical. Unless they are dangerously pitted, smooth them down so they slip back more easily. Should be fine.

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Re: Disassembling front forks - K1 750
« Reply #21 on: January 21, 2024, 10:55:26 AM »
Well, I finally wrestled the booties off of my lower fork sliders with a little more heating/softening with my heat gun and several small plastic pry bar/levers.

You mean like this?

Whilst it looks awful, this rust is not important in terms of function; the important part of the stanchion is the bit that slides in and out of of the lower leg.
Thanks much Lone Builder!  You've made me feel a lot better.
Mine look like this...

Relatively speaking, I guess the tops of my fork pipes don't look so bad after all.  And despite the dark shadows in my picture, the bottoms of the fork pipes are nice, smooth, shiny chrome.

Thanks too for the pictures in your follow-up post!

Check out page two of the FOR SALE Section. “Johnie” sells them
.Thanks again John D, I appreciate your helpful replies.  I just PM'd Johnie reference his D washers.  I hope to hear back from him soon!

Those rubber boots are just stuck. Shouldn’t be glued.
My booties weren't stuck or glued, John.  I could rotate them around the lower sliders quite freely but they were definitely old and stiff.  I finally got them off as described above.

The rust at the top is totally typical. Unless they are dangerously pitted, smooth them down so they slip back more easily. Should be fine.
As I replied to The Lone Builder above, and as you can see in my picture, my fork pipes really don't look so bad!

Would you suggest I clean these up with a bit of chrome cleaner/polish and fine steel wool by hand; or run them across a wire wheel on my bench grinder?

I still consider myself a SOHC apprentice and appreciate everyone's help on my K1 resurrection.
ZT

Offline newday777

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Re: Disassembling front forks - K1 750
« Reply #22 on: January 21, 2024, 11:29:36 AM »
This is what works on the rusted tops. Spray on, wrap with plastic wrap and let sit. Then a brass brush  and rinse off, dry.

Stu
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My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline newday777

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Re: Disassembling front forks - K1 750
« Reply #23 on: January 21, 2024, 12:02:53 PM »
Wrapping with plastic wrap keeps it from drying out.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Online BenelliSEI

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Re: Disassembling front forks - K1 750
« Reply #24 on: January 21, 2024, 12:04:25 PM »
I have a bucket of a phosphoric acid/ water solution. I usually just stand them in that over night. Stud’s solution looks good!