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Fork lengths uneven?


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Hey guys, last season I discovered I had a fork seal leaking. I got the All Balls kit to do the bushings and the seals and finally with the weather warming up these last few weeks I managed to get the forks rebuilt (Thanks Kev's Shed!) and leak free. As I was putting it all together though, I found that one fork seemed about 4-5 mm longer than the other. I realized this when I tried to put the axle through and couldn't do it. 

 

Unfortunately, I didn't check where it was positioned in the top clamp when I was taking it apart (Why would I?) so I'm not sure if it was like that before or not.

 

Has anyone seen anything like this before? I'm wondering if I might have done something wrong during reassembly... I was really careful doing it and kept diagrams on hand to ensure it all went back together in the correct order and facing the right direction so I can't imagine that being the case. Could the slotted adjustment at the top of the fork for damping have anything to do with it? The bike rides fine and because the difference is so slight in height I don't really notice it, but in the back of my head I know it's there.

 

Thanks in advance for any thoughts you guys can share on it.

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Are you saying one stanchion is 10mm  longer than the other or that the assembled fork when set to the same position in the yokes  is ?  
 

If the latter then its likely the forks have been assembled incorrectly. This assumes they are at full extension with no free play. Please check the top out springs & all spacers are in place & the same lengths.
 

If the former & you are sure the forks are assembled correctly then it is possible that a replacement stanchion was a different length to OEM.

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10 minutes ago, Mohawk said:

Are you saying one stanchion is 10mm  longer than the other or that the assembled fork when set to the same position in the yokes  is ?  
 

If the latter then its likely the forks have been assembled incorrectly. This assumes they are at full extension with no free play. Please check the top out springs & all spacers are in place & the same lengths.
 

If the former & you are sure the forks are assembled correctly then it is possible that a replacement stanchion was a different length to OEM.

 

First, my apologies I just went out and looked again instead of going by fuzzy memory. 10mm was a gross overestimation on my part. It's 4-5mm at most. 

 

The assembled forks when set to the same position in the top yoke don't line up at the bottom so the axle can pass through. 

 

I can pop the caps off the forks and fish everything out to ensure it is together correctly. As I said I was careful about doing everything in the proper order so I don't think that would be the case. I'll check it though just so there is no question. 

 

Thanks for a very quick response!

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The length of the extended fork is detemined by the engagement of the end of the fork stanchion against the top-out spring on the damper tube. The damper tube position is fixed as it is pulled into the bottom of the leg by the damper bolt, and as V4 says above, the oil-lock piece is sandwiched in there so if it was missing then one damper will sit a few mm lower and the overall assembly will be shorter by the same amount. I would certainly expect the forks to be near enough to exactly the same length normally.

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Guys, I'm so sorry for the slow response. I had to go get my Covid 19 Vaccine this afternoon and got hung up. 

 

Regarding the oil lock piece I never took it off to do the bushes and seals.

 

Just to make sure I'm following you correctly- you are referring to part #16, right?:
image.png.ee12af051551d07aaba99542defe1a2a.png

 

Is it possible I could have driven part# 11 in farther on one side than the other? 
 

 

EDIT: Apologies if I'm asking dumb questions here. It's my first fork seal replacement.

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Its not possible to separate the stanchion from the slider without  removing the bottom bolt holding the cartridge & the oil stop ring on its base. So please explain how you changed seals & bushings without removing it ? 
 

Re part 11 if it is not seated fully home, then the spring clip will not locate in its retention grove above the oil seal. 
 

It is possible to have slightly different length forks if the spacers are not the same length, or one spring is shorter than the other, but that would normally lead to free play when you pull on the fork. 

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20 hours ago, Blackened said:

Guys, I'm so sorry for the slow response. I had to go get my Covid 19 Vaccine this afternoon and got hung up. 

 

Regarding the oil lock piece I never took it off to do the bushes and seals.

 

Just to make sure I'm following you correctly- you are referring to part #16, right?:
image.png.ee12af051551d07aaba99542defe1a2a.png

 

Is it possible I could have driven part# 11 in farther on one side than the other? 
 

 

EDIT: Apologies if I'm asking dumb questions here. It's my first fork seal replacement.

11 is the bushing and usually slips in without a fight, followed by 10 which is the washer then 21 is the seal which does need to be driven home until you can fit the circlip 17 into its groove. However...none of that affects the extended fork length. I assume you have got the fork cap 19 screwed on tight? Otherwise the length of the fork is totally dependent on the length of the stanchion tube 9 with its end pulling up against the underside of the top-out spring 15. Springs and spacers don't affect this either unless there was no preload as a result.

 

It is possible for the bottom-out cone 16 to not fit exactly into the bottom of the leg and stand up a little proud but I'd have thought the bolt 25 would not be long enough to engage with the thread then. You sometimes need to rattle the leg side to side to get the parts to seat down properly. 

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23 hours ago, Terry said:

11 is the bushing and usually slips in without a fight, followed by 10 which is the washer then 21 is the seal which does need to be driven home until you can fit the circlip 17 into its groove. However...none of that affects the extended fork length. I assume you have got the fork cap 19 screwed on tight? Otherwise the length of the fork is totally dependent on the length of the stanchion tube 9 with its end pulling up against the underside of the top-out spring 15. Springs and spacers don't affect this either unless there was no preload as a result.

 

It is possible for the bottom-out cone 16 to not fit exactly into the bottom of the leg and stand up a little proud but I'd have thought the bolt 25 would not be long enough to engage with the thread then. You sometimes need to rattle the leg side to side to get the parts to seat down properly. 

I had to drive part #11 (Upper bush) in followed by the washer and then the Seal. Part 12 (lower bush) slipped in with no issue. 

The fork cap is fully in and all fasteners were torqued to spec per the FSM.

The bottom out cone came out with the damper as I recall. 

 

I kept the parts in order as I took apart and reassembled them and followed a diagram to ensure they went back together properly si I don't think this is an assembly issue. Looking again at the diagram and thinking back over the process for the lower part:

 

The lower bush clicks into place and slides into the fork lower

Drop the upper bush into place and drive in using fork seal driver and Spacer.

Drop fork seal into place and Drive in using fork seal driver. 

Insert snap ring. 

Drive in dust seal

 

At that point, the assembly can be manipulated to it's longest and shortest reach. Given there is no free play in the fork and the only thing that affects the overall length is the Stanchion itself I have to assume one is slightly longer that the other and I just didn't catch it on disassembly. I've ridden it several times since the job was completed and it certainly hasn't affected performance at all. Thanks for all of the responses guys. 

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Engineering like that is VERY un-Honda-like.  I have done a lot of Honda forks and I have never had a properly assembled set of forks be different lengths when being extended by the fork springs.  It's not my bike, but I wouldn't be able to sleep at night.

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I don't disagree with you on Honda, Cap. They are pretty precise with what they do. I bought this bike used and I have NO idea what could have happened to it with the Previous owner. For all I know he had to replace a Stauncion and it wasn't the same length. I verified they were re-assembled in the correct order after the work I did and had been fine for the two seasons prior to that (other than the seal leaking) so I don't think there is too much need for concern. Its likely I just didn't realize they weren't the same height through the top clamp which had me scratching my head.

 

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Unfortunately, the only way to know for sure is to pull the forks apart again and check everything again...

 

Ciao,

 

JZH

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