Author Topic: Trip Knob Removal (Read 5248 times)

jakec · « **on:** July 23, 2018, 11:39:38 AM »

I'm working on the gauges for my Honda CB400F. I was planning to buy a set of faces, as well as replace my broken odometer. I was wondering if you guys might be able to help me, I cannot get the trip knob off. I read in multiple threads that it's left hand threaded. However now that the gauge housing is apart, I've had pliers around the shaft of the knob, and turning the cap clockwise with all my might (to loosen) isn't getting me anywhere. There is no set screw on the knob.

If you have any info that could help me, I'd appreciate it. Thank you!

Bankerdanny · « **Reply #1 on:** July 23, 2018, 02:40:54 PM »

The shaft is very thin, so I would caution against twisting on it with all your might.

jakec · « **Reply #2 on:** July 24, 2018, 08:38:08 AM »

Quote from: Bankerdanny on July 23, 2018, 02:40:54 PM

The shaft is very thin, so I would caution against twisting on it with all your might.

The shaft is probably 3/16" diameter. It seemed pretty robust as I was cranking away at it! I do see some circlips on the shaft but I think if I take them off I will have to slide the whole shaft out, meaning I would need to then reassemble the whole trip meter.

awrawr · « **Reply #3 on:** July 24, 2018, 12:16:53 PM »

Same bike same problem, same day. I tried heat I tried Force. Nothing worked. The heat started to melt it. I ended up cutting it off and the shaft has axial splines at the end. Well stuck. Wouldn't have come off without pulling the mechanism inside. I'll get a new similar knob from radiospares when I reassemble. Hope that helps.

jakec · « **Reply #4 on:** July 24, 2018, 02:43:31 PM »

Are you saying it's barbed in there like a harpoon? Wont come out unless I trash the knob?

Sorry but I tried looking up "axial splines" and I don't quite get what you mean.

Bodi · « **Reply #5 on:** July 24, 2018, 04:19:02 PM »

Just a splined shaft pressed into the knob hole. I can't imagine a radial spline... "axial" is redundant
i think.

awrawr · « **Reply #6 on:** July 24, 2018, 11:01:29 PM »

Yes. Exactly that. Straight spines, all parallel to the axis of the shaft. I used the word axial to emphasise that there is no hint of any turn, bend, curve or other deviation from straight spines, identical to the ones you will see on your rear brake pedal shaft. (On a much smaller scale!)

awrawr · « **Reply #7 on:** July 24, 2018, 11:15:41 PM »

The feeling i got was that if i pulled hard enough to remove the knob it would distort the internals and cause the mechanism to become misaligned. Much better to trash the knob. Lots of very similar looking knobs available on eBay which can be made to fit with bit of epoxy.

jakec · « **Reply #8 on:** July 25, 2018, 12:24:08 PM »

Gotcha. Thanks for the info and pic! I will try and yank on it a bit more, but I guess I'm probably going to have to cut it off in the end.

jakec · « **Reply #9 on:** July 30, 2018, 08:26:31 AM »

I got the knob off of my donor gauge this weekend. I decided to take some small shears and cut if off and it was still incredibly hard to remove, even when I was resigned to destroy it in the process.

I finally got the odometer assembly out of the shell. The odometer on the donor gauge shows 7,000mi whereas my bike is about 12,000. I was hoping to turn the mileage up on this new gauge. A member on the honda twins forum said you can just force the numbers over, but I gently tried that and it didn't seem possible. I can see how I would remove the number roll. There is a piece of the metal housing that is bent down over the number roll shaft and I would have to bend that out of the way. I would hate to mess up this assembly as I am using it to replace another odometer that has stopped working.

awrawr · « **Reply #10 on:** August 02, 2018, 11:39:45 PM »

A long time ago (1984 i think) I zeroed my odometer during a restoration. I painted the original mileage on the internals for future reference. Now I am restoring it again I have decided to reinstate the original mileage and add that to the odometer reading. Both these adjustments have been achieved without disassembly by firm persuasion. I wouldn't call it force exactly. Neither adjustment caused any damage.

jakec · « **Reply #11 on:** August 03, 2018, 10:34:18 AM »

Quote from: awrawr on August 02, 2018, 11:39:45 PM

A long time ago (1984 i think) I zeroed my odometer during a restoration. I painted the original mileage on the internals for future reference. Now I am restoring it again I have decided to reinstate the original mileage and add that to the odometer reading. Both these adjustments have been achieved without disassembly by firm persuasion. I wouldn't call it force exactly. Neither adjustment caused any damage.

Firm persuasion, so just pushing the roll until it clicks over?

awrawr · « **Reply #12 on:** August 03, 2018, 11:37:06 PM »

Yes. That's it really. I found the left hand-most digit easiest to move so have a go with that one to get a feel for what is required. Grip the rest of the digits with one hand and rotate the ring youre trying to move with the other. It might be my imagination but i think it went easier in one direction than the other - pushing the number away from you. It requires a little force and it does feel horrible. I'm sure if you did it too often something would wear out or snap but this is the second time I've done it to my odo with no problem.

jakec · « **Reply #13 on:** December 07, 2019, 03:58:54 PM »

Anyone have a good suggestion for a replacement knob? I wouldlike it to be as close to the original as possible. Just not sure what search terms to use and what website to look at. I found this site which seems right but I can't find anything that looks right.

https://www.mouser.com/Electromechanical/Knobs-Dials/_/N-5g22

awrawr · « **Reply #14 on:** December 08, 2019, 12:23:52 AM »

I think I searched for "miniature potentiometer knobs" and specified the shaft diameter (3mm ? - can't remember). I selected the "images" option rather than site address listings to home in on the likely candidates. I don't recall exactly where they came from in the end, somewhere in china I think, but I had to buy a packet of 10, so if you are struggling, let me know and I'll post you a few. (...if I can find them...!)

tlbranth · « **Reply #15 on:** December 08, 2019, 11:29:53 AM »

If it's like a GL1000 gauge, and I think it is, I've removed one with heat and one other just plumb had to be destroyed to get it off. However, Pistol Pete has a technique for disassembly and reassembly without removing the knob: https://www.ngwclub.com/forum/viewtopic.php?f=1&t=48713

jakec · « **Reply #16 on:** December 08, 2019, 11:30:29 AM »

Would you mind posting a photo of yours? I couldn't find anything searching images using those terms. If what you have is accurate I would certainly buy a couple from you.

Mine knob is already, via the total destruction method.

tlbranth · « **Reply #17 on:** December 08, 2019, 05:05:28 PM »

I don't have any available. You may need to sign up on NGW to see the pictures but I think it'll be worth it.

awrawr · « **Reply #18 on:** December 09, 2019, 01:47:56 PM »

I will try to find them. I know I haven't chucked them out because I need one for another project. Whatch this space ......

jakec · « **Reply #19 on:** December 19, 2019, 02:37:02 PM »

Any luck on that? Thanks

awrawr · « **Reply #20 on:** December 31, 2019, 02:30:14 AM »

Replacement pot knobs off Ebay.

pjlogue · « **Reply #21 on:** December 31, 2019, 04:43:15 AM »

Does the metal shaft that connects to the black knob go to a thinner shaft farther inside the gauge? I seem to remember this being the case in an old gauge I rebuilt 40 years ago. If this is the case, use a good set of needle nose pliers with serations on the jaws to get a good purchase on the thin rod, heat the end of the larger rod where it connects to the thinner rod with a soldering iron and then twist clockwise. The thin rod part is inside the "caged" area of the gauge.

-P.

Don R · « **Reply #22 on:** December 31, 2019, 01:57:53 PM »

Some are backwards threaded and some have a set screw. This is new to me.

jakec · « **Reply #23 on:** December 31, 2019, 02:39:44 PM »

Quote from: awrawr on July 24, 2018, 11:15:41 PM

The feeling i got was that if i pulled hard enough to remove the knob it would distort the internals and cause the mechanism to become misaligned. Much better to trash the knob. Lots of very similar looking knobs available on eBay which can be made to fit with bit of epoxy.

If you look at this message, that's what the 400 knob is like. the knob is a press fit with some glue. Unfortunate, it'd be nice if it was reverse thread.

The Lone Builder · « **Reply #24 on:** July 08, 2020, 04:01:02 PM »

+1 on the above.

Destruction with a Dremel was the only option.

bryanj · « **Reply #25 on:** July 08, 2020, 11:31:09 PM »

A gauge restorer on the UK site says to use the thinnest dremel wheel you can get to cut along the knob then gently lever open to remove, refit using epoxy in the groove to fill the slot

The Lone Builder · « **Reply #26 on:** July 10, 2020, 04:09:08 PM »

I tried that Bryan.

The one half split as I was trying to lever it off and the second half wouldn’t budge, so I had to cut it!

Now looking for potentiometer, or pot, knobs or a suitable glue tube top.

The problem is most of the above knobs are 6mm and the shaft on the speedo, at least mine, is 5mm.

That was on my practice gauge; the real ones are going to a gauge rebuilder!

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Author Topic: Trip Knob Removal (Read 5248 times)