BB Clutch Assembly - new title

[Scout63]

I’m almost done with my G5 restoration and have hit a wall. I did a full engine and gearbox rebuild, rewire, and, well, everything.  I’m to the point of adjusting the points, installing the carbs and a first start attempt. The gearbox shifts fine, and the engine spins freely on the starter BUT... ...I can’t turn the engine using the rear wheel (with the plugs removed). The wheel will only spin in neutral.  Also, I can’t get the clutch to adjust. If I take up all of the slack in the cable and push rod adjuster, I can pull the clutch lever in with difficulty but it doesn’t feel right. I should have checked this when I first installed the gearbox and then rear wheel.  Pretty sure I’m going to have to crab the frame, which is ok, but if anyone has any thoughts I’d love to read them. It seems to me the problem has to be at transmission input shaft.

[guzzisteve]

Sometimes it it difficult to roll the motor over using back wheel while in gear, especially if fresh. Try using clutch with motor cranking & see if it works easier. I would continue with getting it going first.

[huub]

Just a idea, sounds Like the like the clutch plates are fitted wrong way round. ( dont ask... )

[Old Jock]

Really stupid suggestion but you are trying to rotate the engine in 5th gear and not 1st

I'm guessing you have tried in a few different gears and the rear wheel is completely solid.

If it was the clutch either binding or not engaging you'd still be able to either turn the engine with the rear wheel or the wheel would just spin and not turn the engine. Either way the rear wheel would would spin.

In the past I've had my share of the clutch dragging and making neutral difficult and getting the rear wheel to disengage from the engine but never had the rear wheel locked

Perhaps it is the clutch, but I'm leaning towards something locking up the gearbox, as I've never heard of the clutch locking up the drive train.

Then again I don't what happens when you install the plates wrongly.

I assume you rotated and changed up down the box after final assembly of the gearbox

I'm at a loss sorry

John

[Scout63]

Really stupid suggestion but you are trying to rotate the engine in 5th gear and not 1st

I'm guessing you have tried in a few different gears and the rear wheel is completely solid.

If it was the clutch either binding or not engaging you'd still be able to either turn the engine with the rear wheel or the wheel would just spin and not turn the engine. Either way the rear wheel would would spin.

In the past I've had my share of the clutch dragging and making neutral difficult and getting the rear wheel to disengage from the engine but never had the rear wheel locked

Perhaps it is the clutch, but I'm leaning towards something locking up the gearbox, as I've never heard of the clutch locking up the drive train.

Then again I don't what happens when you install the plates wrongly.

I assume you rotated and changed up down the box after final assembly of the gearbox

I'm at a loss sorry

John

Thanks John and all.  I ran the gearbox through the gears on the bench and it was fine.  I’ve tried rolling the engine using the wheel in all gears with the plugs out.  It is definitely locked, not a compression thing. Since the clutch also won’t adjust I have to assume it’s a clutch to gearbox problem. I’ll just disassemble back to the transmission/clutch and check everything. 

[Kiwi_Roy]

It's not easy to spin by rotating the back wheel, you just sort of inch it over using the play in the gears to give some momentum.
Before you pull it apart again try rolling the bike forward then dropping the clutch (plugs out of course)
I leave my bikes in 1st gear and roll them out of the garage using the clutch as a brake.

[lucian]

Always make sure that the clutch plates actually fit over the splined center hub smoothly before assembling the clutch to the flywheel. I recently got an SD friction plate that would not fit over the hub, a manufacturing flaw. As mentioned, the friction plates go in with the protruding center ring facing the gearbox.  After  bolting the clutch together with the centering tool,  check that the hub will pass through the plates again. Then I'll will install the hub onto the trans input shaft and then assemble the  trans. onto clutch housing. You can use the two long starter bolts as guide bolts screwed into the clutch housing through two of the top the trans bolt holes.   Go easy here as the slightest nudge to the plates can knock them off center. Use the rear drive shaft as a tool to rotate the transmission on the output side until the hub splines engage. After things are bolted up  , with the tranny in gear I test that the clutch releases properly before going any further. I found that a welders vice grip works great for pulling the clutch arm in and holding it there. One side of the clamp fits nicely in the cable end of the clutch arm , the other around the front  of the cable purchase , If the clutch releases as it should you are good to proceed.
Looking forward to some pics of your finished restore. b I have been looking for a G5 , they are beautiful bikes , and hard to come by, congrats.

[moto-uno]

 First of all , have you tried to turn the motor with a screw driver through the timing hole on the case ?
 If the clutch plates are " bound up" , how perchance does that stop the motor from turning ? There
 seems to be a bit of confusion here on what goes on in the bell housing .
 Try #1 first before anyone suggests you waste your time on their speculation . And fresh motors are
 very hard to turn with the rear wheel , hence the suggestion about the timing hole and screwdriver :) .
 Peter

[lucian]

If your clutch lever doesn't feel right and the clutch isn't disengaging, something isn't right.  I would play it safe and run through it again as much of a pain as it is . Make sure to check all of the plates for flatness or distortion. if the stack was bound and force was applied to the lever, or by drawing the gearbox in with the bolts,   the plates could be cupped or damaged. The gearbox should push right on to the clutch housing with little effort once the splines align. Under no circumstances should you need to draw the two together with the bolts . Also , make sure all of the springs are in there sockets when assembling the clutch, stick your pinky finger in there and confirm before bolting everything up tight.

[Huzo]

First of all , have you tried to turn the motor with a screw driver through the timing hole on the case ?
 If the clutch plates are " bound up" , how perchance does that stop the motor from turning ? There
 seems to be a bit of confusion here on what goes on in the bell housing .
 Try #1 first before anyone suggests you waste your time on their speculation . And fresh motors are
 very hard to turn with the rear wheel , hence the suggestion about the timing hole and screwdriver :) .
 Peter

Correct..
Even if you have rooted up the installation, it would not preclude the engine from turning over. You would more likely find that the cutch would not “free” on command.
As mentioned, is there not a nut or something on the front that you can rotate the crank with ?
Notwithstanding all the previous stuff, you’ll be surprised how (relatively) little time it takes to just go back in....

[Scout63]

Really great feedback. The motor spins fine on the starter so I know it is free. During assembly, I triple checked that the clutch plates were installed with the shoulders back to the gearbox.  I used a centering tool and the gearbox mated to the input shaft nicely.  What I didn’t do was check clutch action as Lucian noted before installing the engine/gearbox into the frame.  I’m not going to take any chances and will crab it this week.  Now I’m so glad I took the time to use good Apex electrical connectors when wiring the bike.

[LesP]

Did you try to rotate the rear wheel in gear with the clutch lever pulled in ?

[Old Jock]

I made the point about early in the thread that no matter the position of the clutch the wheel should turn, for it to bind a rotating section has to be contacting a stationary part or something is seriously misaligned

As I've never installed the plates backward I don't know what that does, it's not beyond reason that the plates could foul the casing but it'd moot as Scout has ruled it out

I remember being in similar position with a Daytona, turned out the UJ cage was on the wrong way and the UJ was contacting the cage 

I'd do as Scout is about to and that is tear it down, but before doing that I'd also pull the pushrod and check all was well there.

It wouldn't be the first time I've had 2 separate problems and thought I was diagnosing 1

John

[Scout63]

Did you try to rotate the rear wheel in gear with the clutch lever pulled in ?

Hi Les.  The clutch lever doesn’t feel right. Lever pull is very hard.  Wheel won’t rotate when I pull it. 

[LesP]

Hi Les.  The clutch lever doesn’t feel right. Lever pull is very hard.  Wheel won’t rotate when I pull it.

Greetings Ben.
Can a plate be installed the wrong way round I do not know, perhaps it would fit but end up with the springs compressed more, that might make for a hard lever action but would imagine there would be next to no adjustment left in the cable if the Loop cables are anything to go by (Near all gone on a new cable)
The clutch action on my bike is very light (stock weight springs) and I removed the plugs today to see, turns fairly easy in gear and disengages when the lever is pulled in for easy freewheeling.

The travel of the clutch pushrod is very basic only pushing on the spring plate so should be smooth and light action (unless the seated spring pressure was excessive)

The gearbox solid in gear is odd at best if it shifted through the gears rotating the input and output shafts.
You could check the crankshaft for end float via the hole in the bellhousing to check it is not under preload to the front bearing thrust face.

[LesP]

I fit a new 99 link plus the joiner IWIS drive chain to the Commando yesterday (with the primary chain off ! and the gearbox had moved ) and cut two links off it giving no thought to the primary.
I then found out I needed a 100 link total chain which it was before cutting. 

Oddly enough I googled to see if there was a IWIS importer and emailed them to see if they had M106SL chain which they did in 5 metre lengths, but had three 100 link chains from an industrial over order.
I couldn't believe my luck given the time one would take from the UK.

On the Eldorado I had taken many pictures and remember the flywheel and clutch which I had done on a Sunday then had dinner forgetting to take a pic of torqueing the ring gear bolts so afterward reset the torque wrench and took a staged pic giving it little thought.
Some time later someone asked the torque setting for the ring gear bolts on the FB Loop page and Charlie M posted the setting, I thought I would add my picture showing the reading anyway.
I then noticed to my horror the setting on the wrench showed that for the flywheel bolts being much higher so deleted the reply pic.
The engine and gearbox were in the frame by then and it played on my mind for a couple of weeks, I was sure they were torqued correctly but that picture cast doubt.
In the end I removed the gearbox to find they were torqued correctly, its the way sometimes.

[Scout63]

Oh that it were my Commando clutch needing work Les.  Remove the primary cover and there it is. I know that it will be something installed wrong when I get in there.  At least everything is shiny and clean.

[Chuck in Indiana]

Maybe something as simple as the springs not seated in the wells?

[Antietam Classic Cycle]

Maybe something as simple as the springs not seated in the wells?

This ^^^. Did you align the dot on the pressure plate with the line on the flywheel?

[LesP]

It does not explain the not rotating in gear though?
It could be tested the other direction, spark plugs removed, manually rotate the engine via the crankshaft snout if possible in both neutral and in gear as a comparison.

[Scout63]

This ^^^. Did you align the dot on the pressure plate with the line on the flywheel?

I did Charlie.

[Scout63]

It does not explain the not rotating in gear though?
It could be tested the other direction, spark plugs removed, manually rotate the engine via the crankshaft snout if possible in both neutral and in gear as a comparison.

I tried it from the front Les. I can turn the engine using the crank bolt on the snout in neutral.  In gear the engine won’t turn and I just keep tightening the bolt, and we all know what happens when you put too much torque on the rotor bolt. I just wasn’t willing to put much on it.

I got a couple of hours into the bike tonight and have it stripped down to the lower frame rails.  Tomorrow I’ll crab it and pull the gearbox.

[Scout63]

This was my first time crabbing a Tonti frame.  Working slowly it took about 2.5 hours. Here it is. If anything looks awry or unsafe, please sing out. I’ll pull the pushrod, gearbox and clutch tonight and hopefully something will be obviously wrong.

[lucian]

I would add a couple of straps to the front . Block the fork bottoms to the table. Straps  around the fork tubes above the lower triple tree, angled slightly rearward down to the lift table opposing the forward angle of you overhead hook.  crank the forks down tight to the blocks. Its a good idea to strap the jugs down either side too.  I would be afraid  the angle of your top hook may nudge the bike forward  when wresting with things.

  My 2cents  Good luck tonight

[Scout63]

I would add a couple of straps to the front . Block the fork bottoms to the table. Straps  around the fork tubes above the lower triple tree, angled slightly rearward down to the lift table opposing the forward angle of you overhead hook.  crank the forks down tight to the blocks. Its a good idea to strap the jugs down either side too.  I would be afraid  the angle of your top hook may nudge the bike forward  when wresting with things.

  My 2cents  Good luck tonight

Thanks Lucian. I will strap down the forks.  It was a little jiggly pulling the gearbox and I would never be able to get it back together with the bike moving around.  The gearbox shifts fine on the bench.  I did reinstall the pushrod orings and checked and regreased the thrust bearing and bodies.

[Chuck in Indiana]

Looks like it's time to pull the flywheel and find that spring that popped out of the spring well when you were assembling it. 

[lucian]

You can give those springs a little pinch in on the end with some pliers and they will hold right on to the clutch plate , still check with your pinky before bolting up tight

[Tom H]

A little Permatex #2 holds the springs to the flywheel nicely.

Also DO NOT FORGET THE PUSH ROD CUP!!!!

Tom

[Scout63]

Clutch looked fine and plates were installed right. Still searching.

[jacksonracingcomau]

Late to the party but
Box changes and turns over on the bench
Engine turns over assembled in neutral
Doesn’t turn over in gear assembled

If it we me, I’d put box back on but nothing behind it
If problem solved, it’s in the rear end
Clutch “feeling” odd may be entirely seperate thing, adjustment or cable issue?