Unofficial Royal Enfield Community Forum
Royal Enfield Motorcycles => Bullet with the UCE engine => Topic started by: Wombat on September 08, 2021, 03:06:10 am
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Hi everyone.
I'm a new RE Classic 500 owner (2018) and new to this forum. Last week my bike was knocked over and laid on the left side. The gear shift lever obviously took a knock, as the next time I used it the lever flopped down by the foot-peg.
I've found a previous thread with the exact same issue. The final fix was to realign a bent piece (I don't know which) via gentle use of a hammer. That thread is:
https://forum.classicmotorworks.com/index.php?topic=8796.msg99245#msg99245 (https://forum.classicmotorworks.com/index.php?topic=8796.msg99245#msg99245)
I'm not keen on taking a hammer to my bike (at least not yet), so would love some advice/recommendations on what the issue may be.
I've removed the RH crank case cover, and the first issue was obvious. The end of the gear shift shaft that slots into the bottom of the rocker shaft was disengaged. See photo attached which shows the gear shift shaft (1) disengaged from rocker shaft (2).
I put them back together, but the angle of the rocker shaft doesn't look right to me, and the protrusion on the gear shift shaft is angled. I would think this should be vertical? See second photo attached.
My questions are:
1. Should the rocker shaft have that angle?
2. Could something higher up be bent, such as the gear change striker or the rocker shaft stop pin?
I have also attached some diagrams of the gear shift assembly and RH crank case in case it gives anyone any ideas.
After I initially put the shaft end/rocker back together, I put the bike together again and went for a ride. Shifting was off, and after a few minutes the pieces disengaged again and the level dropped back down by the foot peg. I've now got it pulled apart again, but am scratching my head as to what could be damaged and what to do next.
Thanks in advance.
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I don't know about whether it could be bent and if this could cause your problem. But, have you ruled out the disengagement being due to additional lateral movement of the shift shaft, as a consequence of the impact? Could a blow from the left side affect the spacer or the 'bearing' on the right side? Has the left side housing been pushed in, giving more play?
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Yes, the finger on the shaft should be a straight 90°. Not bent or leaning over at all.
Has the weld broken?
https://www.sparezo.com/royal-enfield-gear-change-shaft-uc-classic
In normal use the finger should not be able to come out of the fork. The black plastic spacer that keeps them together may be damaged?
Possibly bent something further up on the selector mechanism?
Might mean you have too much travel on the gearchange shaft allowing the finger to disengage?
PS, make sure you replace that oil pump output seal...........
Just had another look at your photos.
And yes, the finger should be pointing vertically.
Yours is leaning forwards, something is bent.
(https://i.ibb.co/pPLfmXp/Oil-flow-1.jpg) (https://ibb.co/6ZWHds5)
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It looks like the rocker shaft may have somehow come out of the upper or lower pivot bearing. I'll be very interested to see what you find.
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What Haggis said!
PS, make sure you replace that oil pump output seal.
What gear is your bike in? The fork moves the shaft back and forth. That's normal. Have you tried shifting and getting into neutral?
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Thanks everyone for your replies.
@Ove I don't think the issue is due to additional lateral movement of the shift shaft. The left hand case is good, and the black spacer bearing on the end of the shaft appears undamaged.
@Haggis Thanks for confirming the finger on the shaft should be 90°. That is what I thought. The black plastic spacer seems fine, and the weld has not broken - the shaft looks quite normal, but has just rotated a few degrees which is the root of the problem. As you suggest, the issue is possibly something further up on the selector mechanism. I was hoping to not have to go there, but will try looking at that this evening.
Just to confirm, the missing oil pump seal goes where I've shown in the attached image? (sorry, I can't figure out how to paste images in line).
@ozpacman I think you may be right. I suspect the issue may be with the upper pivot bearing. Fingers crossed. I'll keep you posted.
@Guaire The bike is currently in neutral. I've tried moving the shaft back and forth as it would do when driven by the gear shaft. The range of motion looks normal, it's just rotated too far to the front.
I have one more question - the manual mentions use of special tool ST 25123-4 Extractor for 5 speed gear box pivot pin. It looks like a bolt with a handle threaded onto it. Does anyone know of an alternative for this (just a regular bolt and some pliers/vice grips?) If so, does anyone happen to know the bolt type?
Thanks again everyone for your help with this. I really do appreciate it.
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You need to remove the starter motor first.
Yes, a normal bolt will screw in fine and pull up with a pair of pliers. It's not held very tight. 🔧🔧👍
Be aware that the alloy block that supports the bottom end of the shaft has to be fitted the correct way up.
Hope you find something otherwise it may be a bent selector fork.??
(https://i.ibb.co/60D807g/Screenshot-20210908-181305-Drive.jpg)
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You need to remove the starter motor first.
Yes, a normal bolt will screw in fine and pull up with a pair of pliers. It's not held very tight. 🔧🔧👍
Be aware that the alloy block that supports the bottom end of the shaft has to be fitted the correct way up.
Hope you find something otherwise it may be a bent selector fork.??
Thanks very much Haggis. I've removed the starter and the rocker shaft return spring pivot pin (was easy with bolt and pliers as you said).
The rocker shaft sits straight with the pivot pin removed. However, in that position the left arm of the return spring impedes replacement of the pivot pin. The only way to get the pivot pin back in is to rotate the rocker shaft back to the out of alignment position - back to square one.
I'd like to remove the assembly to see if the arm of the return spring could be bent, or to trace it further up the line to see what else may be bent. Problem is, I can't figure out how to remove the striker, or disengage the striker from the cam plate assembly. The manual says to simply "Remove the rocker shaft assembly by gently tilting and twisting out". It doesn't seem to want to just tilt and twist out for me.
Any advice on how to remove the rocker shaft assembly would be very much appreciated.
Thanks again.
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Just as it says, a bit of wiggling and a twist to unhook it from the cam plate.
(https://i.ibb.co/5MnbNj5/Screenshot-20210908-200655-Drive.jpg)
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Just as it says, a bit of wiggling and a twist to unhook it from the cam plate.
Alright, I got it out! Thanks for the advice. Everything in this assembly looks good to me, except for one thing. When looking down on the rocker shaft assembly vertically, the forked receptor at the bottom of the shaft doesn't appear to line up with the primary axis of the upper section.
See the attached photo. The red line is approximately the center axis of the upper plate that takes the bearings and springs. The green line is the approximate axis of the forked receptor at the bottom. The angle difference is pretty much the same as that causing the primary issue when it is assembled (and caused the finger on the gear change shaft to fall out).
Overall, it looks as though either the top or bottom plates on the rocker shaft may have bent/twisted. However, it's a pretty beefy unit.
Questions:
1. Is it likely that it could have bent/twisted despite being such a solid unit?
2. Is it worth trying to bend the bottom forked plate back so it aligns with the center line of the upper plate? I would use a length of pipe on the fork for leverage, and hold the body in a vice.
Ultimately, I'd like to replace the rocker shaft with a new one. But, it will probably take weeks to get the part and the window for riding in Canada is closing down fast...
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Is this it? This is from Hitchcock's Parts Book Online, 2018 Classic. Looks to be in-stock. Most items I get are 4-7 days door-to-door. Order today and you'll likely have it Tuesday. - ACR -
https://accessories.hitchcocksmotorcycles.com/30915?qty=1&continue_url=https%3A%2F%2Fwww.hitchcocksmotorcycles.com%2Fpartsbook-pages%2F5394
PART No. 570643 ; GEAR CHANGER ASSY. ; £21.01
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Is this it? This is from Hitchcock's Parts Book Online, 2018 Classic. Looks to be in-stock. Most items I get are 4-7 days door-to-door. Order today and you'll likely have it Tuesday. - ACR -
https://accessories.hitchcocksmotorcycles.com/30915?qty=1&continue_url=https%3A%2F%2Fwww.hitchcocksmotorcycles.com%2Fpartsbook-pages%2F5394
PART No. 570643 ; GEAR CHANGER ASSY. ; £21.01
Yep, that's it. Good to know the shipping times can be that quick. Their estimate is 10 to 20 working days. I'll go ahead and order it.
As an update though, I bent the fork on the bottom of the rocker shaft back into alignment and have put the bike back together. It now sits at 900 to the bike as it should, and at least in the garage it's shifting through the range of gears both ways. It's all pretty much ready to go (I need a touch more oil), so will take it for a spin tomorrow and see if the shifting works as expected. Once the new shaft arrives, I'll put that in just to be sure.
Thanks everyone for your help with this (especially Haggis). I'll post another update once I know how it runs.
Cheers
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Well done.
Was it easy to bend back?
Or was it the shaft that was twisting?
As you say, it looks a sturdy bit of metal.👍
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It took quite a bit of force to bend it back. I used a piece of pipe about a foot long and had to apply a generous amount of force to bend it back. The forked piece on the bottom is so short and compact I suspect it was actually the shaft itself that was twisted. The fork itself is too stubby to bend and the weld is solid. I'm kind of surprised there was enough force applied in the lay over to twist the shaft in the first place, but that seems to be what has happened.
Anyway, it went right back to where it was meant to be so hopefully all will be good. I'm hoping that the way the pivot pin inserts into the upper plate on the rocker shaft, it would have prevented any excess travel further up the line and therefore all will be okay up there. I really don't want to deal with bent shift forks etc.
Fingers crossed the test ride goes well today!
Thanks again.
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So the bike is running well, except it now finds neutral when downshifting from 3rd to 2nd gear (pretty much every time). Does anyone have any ideas on what may be causing that?
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I'm hoping someone may have an idea of what is going on with this? Downshifting was all good before the rocker shaft got bent, so presumably something else may have been bent further up the line. Pretty sure the bike was in first gear when it fell over, but could possibly have been second. If something else was damaged up the line from the rocker shaft, and ideas on what the most likely candidate could be to cause false neutrals downshifting from 3rd to 2nd gear? Could it be the neutral finder cam plate or shifting forks?
Thanks in advance for any advice or suggestions.
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It must have taken quite a hit to bend the assembly as it did. It's possible that another less robust stamped part of the assembly where the springs attach could also be bent or misaligned, but you'd have to take it apart once again to inspect the entire assembly, and even then there are no guarantees. If it were me, and mind you I'm cheap as hell, I'd order the new gear change assembly and replace it as suggested by others. But that's just me. It's a touchy mechanism.
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I have a sneaky feeling it could be a bent selector fork.
Difficult to tell without a full strip down and split the cases to visualise the actual parts.
The only bits you can get to from the outside, you have already been there.
When you shift from 3 to 2, are you going past 2 and into neutral proper or are you finding a false neutral between 3 and 2?
Meaning 2 is not being fully selected.
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Thank you both for your replies. As I always I am very grateful.
I've ordered a new gear change assembly and will install as soon as it arrives. I guess there is a chance that alone will make a difference, but I suspect something more will also be required.
Symptoms are:
It appears to be shifting from third past second to actual neutral. If I stop at that point, the neutral light is on and the bike rolls with the clutch out.
If I shift up again from that neutral position it engages second.
When the bike goes into neutral after downshift from 3rd to 2nd, the bike will not shift down to first from there. It will however shift easily back up to 2nd, after which it will shift down to 1st normally.
My workaround while riding for now is to downshift from 3rd to neutral, and them immediately up to 2nd and then back to 1st when stopping or otherwise requiring 1st gear.
Neutral can be a bit difficult to find from 1st gear. It's easier to go up to second and then move back down to neutral
Haggis, your suspicion regarding the selector forks is probably correct. Based on the symptoms do you still have that sneaky feeling? If so, do you have a hunch about which fork is most likely to be bent?
Cheers
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This the bit you can get to from the outside, that you straightened.
I would hope that your replacement part will fix your problem as there may be other twists or bend on the damaged one.
(https://i.ibb.co/z40FZVS/RE-UCE-Gear-shifting-Mech.jpg)
The rest is on the inside and requires a full engine strip to get at it.
(https://i.ibb.co/Ny6MvjY/RE-UCE-Gearbox.jpg)
(https://i.ibb.co/WB1WzVV/s-l1600-9.jpg)
(https://i.ibb.co/tPNDL8k/s-l1600-8.jpg)
The notches in the camplate are each gear position.
A bent selector fork would move the gear more/less than it should.
Do you still have a positive click from gearbox as each gear selects.
Engine off is fine but you might need to jiggle the back wheel a little .
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Here's a video that offers a rare insight into the gearbox and its actuation. I believe this will be of interest to anyone who is trying to help you solve your problem. It's very enlightening. Enjoy.
https://www.youtube.com/watch?v=4xgvtWbPviA
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Another possibility is that some other bend or misalignment in the overall shifter assembly may be resulting in a slight over-rotation of the shift cam plate when shifting from 3rd to 2nd. As a result, the spring-loaded anti-skip mechanism shown in pink may not be fully seating as intended in the detent on the outer profile of the shift cam plate. All speculation mind you, but you'll know soon enough when you replace the shifter assembly.
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Thanks again guys. Your responses are GOLD, and that video is great. Provides nice insight.
Haggis, yes I get a positive click when I select gears.
Mad4Bullets, thanks for your advice. I wasn't aware of the anti-skip mechanism and I like the idea of what you're suggesting. I'm not confident enough to strip down the engine to get to the shift forks etc, so if it gets to that point it will be a trip to a dealer. The nearest is quite some way from here, and cost may be prohibitive so definitely hoping not to have to need that.
I'm hoping that as you both suggest, replacing the damaged shift mechanism will take care of the problem. I think the best thing now is to just wait for that to arrive and reassess once I have that installed. Fingers crossed that takes care of it. I'll update here once I get to that point and know either way.
Thanks so much.
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Yes, fingers crossed. Looking forward to a positive result.
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Have you ruled out any denying of the cover around the Bush area?
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Have you ruled out any denying of the cover around the Bush area?
I'm not quite sure what you mean by this. Are you suggesting the housing around the black spacer on the end of the gear change shaft could be damaged? If so, no I've not considered that. I'll check when I pull it apart to install the new rocker shaft. If that's not what you meant would you mind clarifying a little please. I'm open and grateful for any and all suggestions and possibilities. Thanks.
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Sorry, auto correct got the better of me. "Denting", not "denying". I was wondering if the gearshift side could be pushed in allowing the opposite force to rearrange the Bush end? Just a thought.
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Aha. Now I get it. I don't think that has happened. The gear lever side all looks good. Worth checking though. Thanks.