Grubee Clutch Slipping with Wet GB

I

Irish John

Guest
Today I finally abandoned the wet 50/50 gear oil/engine honey GB. I gave it over 100 kms but it was a heartbreaking experience and the clutch slip got so bad I was down to 12 mph at high revs on hills and pedalling my guts out. It slipped on the flat as well and probably slipped going down hill too. I've taken the cluch out to look at it and include pics below.
I think it looks OK although I'm sure the clutch pads are impregnated with oil mix and wonder if it will work again. I'm going back to my white lithium grease and I hope the bike gets back to speed. I think I'll be happy if it chatters on hills like it used to and I'll probably be tempted to add a few squirts of oil and cause the slipping to start again.
The pads are jet black but they look intact. I've forgotten what colour they were originally and I hope I'm not responsible for burning them black as coal!
The wet GB has worked for others but it didn't for me. If a solution is found I can always return to a wet gearbox. The clutch was getting so hot that you couldn't touch the gearbox casing. If anyone notices anything from the attached pics and can tell me if my cluch looks OK i'd be most gratefull.
I nearly tried replacing the 50/50 mix with pure 20/50 AMSOIL as per a recent suggestion but couldn't get it here and I'm over experimenting for the time being.
The desire to improve on good enough has got me into a fix and I'm suffering a blow to my mechanical confidence.
I wonder if I should lightly sand the pads to give them some grip?
 

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I also have this gearbox, and it is getting hot, SEEMS to slip a bit on steep hills, but not too bad, but it does get hot. I have synthetic grease on the gears, no oil. Sure gets hot. I weigh about 180 and there is the Honda 4 stroke 50 cc engine running the bike. I wonder what to do to make it run cooler and hopefully better. It seems too hot to last very long like this.
 
I used lithium grease because the kit instructions said it was probably the best if you aren't going with a wet box. How much grease have you got in there? I put in plenty and then add more.
 
Clutch Slip and gearbox heat

I only have the gears coated with grease. Next I am going to pack the gearbox with white lithium grease and see how that goes. I live in hilly country. This Honda 4 stroke is working, I'm peddling, and the motor is not putting out enough. Also I plan to drill a hole in the exhaust, that may help too. When starting off I peddle and then engage the clutch and it always chatters, then it will catch and start speeding off, but I can feel the slipping going on too, and especially if there is any stress on the motor, like a hill.
 
I only have the gears coated with grease. Next I am going to pack the gearbox with white lithium grease and see how that goes. I live in hilly country. This Honda 4 stroke is working, I'm peddling, and the motor is not putting out enough. Also I plan to drill a hole in the exhaust, that may help too. When starting off I peddle and then engage the clutch and it always chatters, then it will catch and start speeding off, but I can feel the slipping going on too, and especially if there is any stress on the motor, like a hill.

That's not what I wanted to hear Acronn cos I was hoping my bike would go back to fast cruising & no slipping and even on hills I'd rather it laboured & juddered when it gets down to 25 km\hr than revving up and slipping. I take it you have a 48T sprocket and a freewheel drive sprocket. At present I have just greased the gears. I think I remember from the last time that too much grease isn't necessarily that good. The 5/16" hole in the silencer I think has improved accelleration a bit and it sounds better out the back. I'll report back tonight when I take it over the mountain and back. I'm expecting to have to sweat on the big hills but if it starts slipping I won't be pleased.

Where can I get a 52T sprocket supplied to Australia by express post?
 
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Upon further inspection

I pulled off the gearbox cover, and the only thing I can see that is out of the ordinary is the unusual wear on the inside gearbox cover from the spinning of the clutch, just touching the cover and lightly grinding into it, so I wanted to stop that from happening at all, and I have to learn how to remove the clutch. There is a blade screwdriver groove at the end of the spindle - and what looks like about a 1.25 inch fender washer also attached to that heavy-duty screw that holds the clutch flywheel into place, and this is just a bit sloppy loose to hold the clutch assembly into place, so I feel like that should either be bushed or the screw tightened, but when I tried to tighten - just tried with no real hope to get it to move, and had the motor switch off, well the whole spindle wants to move so there has to be a method to remove this flywheel/clutch. I have been searching the posts but can't find the approriate instructions. Oh well, it's just a fun hobby for me but I sure would like my bike to haul *me* up the hill.
 
I pulled off the gearbox cover, and the only thing I can see that is out of the ordinary is the unusual wear on the inside gearbox cover from the spinning of the clutch, just touching the cover and lightly grinding into it, so I wanted to stop that from happening at all, and I have to learn how to remove the clutch. There is a blade screwdriver groove at the end of the spindle - and what looks like about a 1.25 inch fender washer also attached to that heavy-duty screw that holds the clutch flywheel into place, and this is just a bit sloppy loose to hold the clutch assembly into place, so I feel like that should either be bushed or the screw tightened, but when I tried to tighten - just tried with no real hope to get it to move, and had the motor switch off, well the whole spindle wants to move so there has to be a method to remove this flywheel/clutch. I have been searching the posts but can't find the approriate instructions. Oh well, it's just a fun hobby for me but I sure would like my bike to haul *me* up the hill.

Acronn, Taking the clutch out is easy. I've attached 2 photos with instructions to help you. The clutch & bell housing have a bit of movement even with the bolt fully tightened so that is normal. They make a clanking noise if you push or pull them and that's normal too.
First you hold a screwdriver through the hole on the bell housing and that will lock up against the gear wheels and allow you to turn the nut so it comes undone. The keyed flange will then prise out easily with a screwdriver blade underneath it. When that slides off the shaft the bell housing and clutch will also slide off. You can get all the oil off the cluch and it will work again.
To reassemble you do it all in reverse order and Robert is your Mother's brother!
Hope this helps you.
My bike is back to form with a light greasing of the gears and no slipping clutch. I am so pleased and it goes nicely at about 28 mph. There's a bit more vibration which might be because the wet gearbox caused a bit of stress to the motor but no terrible rattles. I have to work hard on big hills but that is just what these engines are like with a 48T sprocket. With a 52T my max speed would probably be about 25 mph and I might be able to bear that.
 

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Pleased to say that going back to grease has totally solved my clutch slipping and the bike runs as normal again. It's no noisier and it only gets warm now and not hot to touch.
 
Hi John, i agree the grease works good enough, i weigh about 95kg and i'm using a 56 tooth sprocket, hills are no problem and the g/box is quiet at 50 kpm, however i think if i can get my sturmey archer hub idea to work that should fix the grabbing at low speeds.
 
I pulled off the gearbox cover, and the only thing I can see that is out of the ordinary is the unusual wear on the inside gearbox cover from the spinning of the clutch, just touching the cover and lightly grinding into it, so I wanted to stop that from happening at all,.

Acronn, are you sure the grinding mark on inside cover of GB isn't from yhe bolt that holds the first gear wheel on. That is a very common problem and you may need to use a thinner washer or replace the bolt with one that has a thinner head or file off the head of the bolt or at least two of the above. Sound very much like this is the case.
Incidentally I cannot belive that you can do 50 km\hr with a 56T sprocket. Your front drive sprocket must have less teeth than mine. I weigh 84 kg and I cannot get that speed out of a 56T - no way.
Sorry Acronn it's Cheap Ride that gets that speed not you - I muddled the messages up.
 
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