4G T-Belt Transmission (Honda)

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Irish John

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I have a few queries regarding the 4G Honda gearbox:
1. I notice the clutch bell has a bushing and not the bearing as per the HuaSheng model. Does this mean the bushing will wear out very quickly like on the older Gruibee GBs and will require a new bell housing and bushing every 2 - 4 thousand kilometers?
2. Does the 11T freewheel break under increased torque through the shaft?
3. Is this GB geared to work with a 48T rear sprocket? If not what size is the best sprocket and will it cruise at 30 mph like the older GBs?
4. Can it take a 1 piece wide crank or must it have the 3 piece crank with the short crank arms?
Thanks.
 
Hi Irish John, you sir, were right on with your assessment of the G4. The gear ratio's wrong. Expensive lesson but I've purchased an EZM to replace mine. I should have heeded your first Review!
 
Hi Irish John, you sir, were right on with your assessment of the G4. The gear ratio's wrong. Expensive lesson but I've purchased an EZM to replace mine. I should have heeded your first Review!

Hi Whizzerd, are you talking about my assessment of the Mark2 4G or the Mark1 about which I was certainly not polite and which I found to be a totally useless gearbox. The Mark2 has been re-engineered and I have no direct experience of it but the advantage in the reduction in the size of the large pulley wheel which was very necessary will be lost to some extent by reducing the drive sprocket from 11 tooth to 10 tooth.
In this thread I am just trying to find out if anyone can tell me whether the 4G for Honda has a bell housing & bushing because if so those have all been problematic on the many old style Mark2 gearboxes I have built and they only last about 2500 kms before they become too loose to work effectively. This is what I'm trying to find out.
These things are important only because I have a lot of customers out there who were supplied with old style Grubee kits for which there are now no spares and they absolutely have to have the bell housing & bearing replaced about every 2500 - 3500 kms and the drive sprockets at about 4000 kms.
The Australian Grubee importer doesn't care about trivia like old models and the need for spare parts when he's busy flogging the new belt drive kits.
I had hopes that someone would produce a trouble-free gearbox by now but it seems to be still in the pipeline.
 
Hi again Irish John,

The Honda unit uses the oilite bearing which initially has to be soaked in oil for several hours before using. The Huasheng box uses the Huasheng supplied clutch and bearing. Honda did not come with this, so 4G made up the bushing thing which will need periodic maintainance.

I also do not like the freewheel mechanism as it is another weak point in the design.

66
 
Yes John, my unit is the Mk. 1. Just a few months after I purchased it upgrade kits were made available through Grubee. The new version is still a 5:1 ratio gearbox if I'm not mistaken. Talking to other mb'ers at the Motorbike Show last week confirmed my experience w/ the G4. Quentin's EZM equipped bike with several thousand miles rides like a Champ! That's why I purchased one.
 
Hi again Irish John,

The Honda unit uses the oilite bearing which initially has to be soaked in oil for several hours before using. The Huasheng box uses the Huasheng supplied clutch and bearing. Honda did not come with this, so 4G made up the bushing thing which will need periodic maintainance.

I also do not like the freewheel mechanism as it is another weak point in the design.

66

The standard grubee gearbox bushing do not require periodic maintenance so much as periodic replacement and the period is relatively short and the availability of replacement bushings and bell housings is zero for the old gearboxes.
I have looked up Oilite bearings and super oilite and super 16 oilite and they look like good stuff. I wonder how long they last given that I have now established that the old Grubee gearbox shaft bushings need replacement between 2500 and 4500 kilometers. After that distance nasty things can happen because the lateral movement of the bell housing can damage the shaft and shaft key and potentially the teeth on the middle gear wheel.
Running a wet gearbox might help but then you have clutch slipping problems.
It's really no big deal because the replacement bushing and bell housing is only $25 or $30 but in Australia the dealer has stopped supplying spares for old gearboxes.
I like the sound of the new 4G Hs kit but I'm not that keen on having to have the HuaSheng that it goes with. Once you have got used to Honda its hard to go back to HS and the difference is very noticeable.
So I guess I'm wanting to know how long the bearings on a 4G Honda gearbox last?
 
On the old Mark 2 Gearboxes I am trying an experiment by putting several bushings and bell housings in a deep oil bath of fairly heavy gear oil after heating them to a high temperature with a Mapgas torch. I'm leaving them in the bath for 3 days to see if the oil impregnates the bushing and housing and thus prolongs their working life. I'll report back in a couple of months when I'll know if it works. I see my queries re the Mark 3 Grubee gearbox have gone unanswered on the other thread I started.
http://www.motoredbikes.com/showthread.php?t=28487
Mustn't be a popular gearbox methinks.
 
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John, How the the three day oil soak on the bushings go? I have a Honda tran and just checked my bushing by putting a torch to it. The bushing was full of oil. I did drop it back in a cup of oil to soak over night. I'll be putting the bike back together tomorrow. Hope the bushings last more than a few hundred miles
 
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