G2 Clutch hub rebuild or alternative assembly?
-
- Posts: 14
- Joined: Thu Aug 10, 2017 2:16 pm
- Location: Jockland
G2 Clutch hub rebuild or alternative assembly?
1961 G2 Clutch basket assembly centre in knacked.
The bearing/rollers are complete and showing little wear but a helluva lot of play when all assembled. All the play is in the centre both outer and inner of the bearing.
Has anyone successfully rebuilt one of these or come up with an alternative? as obviously other than the rollers no parts are avail.
The bearing/rollers are complete and showing little wear but a helluva lot of play when all assembled. All the play is in the centre both outer and inner of the bearing.
Has anyone successfully rebuilt one of these or come up with an alternative? as obviously other than the rollers no parts are avail.
- Rob Harknett
- Member
- Posts: 11211
- Joined: Mon Jan 01, 1990 12:00 am
- Location: ESSEX UK
Re: G2 Clutch hub rebuild or alternative assembly?
The play you refer may be quite normal on the clutch.
- Ozmadman
- Posts: 2651
- Joined: Wed Dec 14, 2011 1:02 am
- Location: ESSEX UK
Re: G2 Clutch hub rebuild or alternative assembly?
Thought you could still get a clutch centre? Bit expensive though I seem to remember. You need to be sure you get the correct one as there are two different main shafts, the original and a modded one which is dependant on the age of the gearbox. Also, make sure it has the G2 clutch (determined by the amount of plates and whether any have a single sided frictions surface or not.) Also, as virtually all the gearboxes are interchangeable between the 350 and 250 there is a possibility you may have a 350 clutch and gearbox fitted and again two different main shafts with two different clutch centres. The gearbox numbers won't be any guarantee either as internal parts are generally interchangeable too. I have a spare G2 250 box which had a 350 main shafts in it.
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
-
- Posts: 14
- Joined: Thu Aug 10, 2017 2:16 pm
- Location: Jockland
Re: G2 Clutch hub rebuild or alternative assembly?
Gee - that makes me feel much better now! LOL.
So question now is how do I know what I have? Are there measurements for makeshift Tec?
So question now is how do I know what I have? Are there measurements for makeshift Tec?
- Ozmadman
- Posts: 2651
- Joined: Wed Dec 14, 2011 1:02 am
- Location: ESSEX UK
Re: G2 Clutch hub rebuild or alternative assembly?
Go here and look at page 55. http://archives.jampot.dk/book/Workshop ... models.pdf This will give you all the main shafts measurements then check what clutch you have by looking in the owners manuals here.
http://archives.jampot.dk/book/ Be aware that the workshop manual above is for all models so just make sure you are on the right section if you need to check anything else out.
http://archives.jampot.dk/book/ Be aware that the workshop manual above is for all models so just make sure you are on the right section if you need to check anything else out.
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
-
- Posts: 14
- Joined: Thu Aug 10, 2017 2:16 pm
- Location: Jockland
Re: G2 Clutch hub rebuild or alternative assembly?
Thanks for the info. If I use the roller cage as a starting point - the outer circumferance is 1mm smaller then the basket housing and the inner is 0.7smaller than the iner hub. The rollers themselves should be 1/4 (6.35mm) mine are 6.25 - but without knowing the tolerances it dont mean much.
The output shaft is 18.4mm and the clutch is 7 plates total with 2 x steel outers and 3 friction all in good nick.
The output shaft is 18.4mm and the clutch is 7 plates total with 2 x steel outers and 3 friction all in good nick.
-
- Member
- Posts: 15
- Joined: Fri Mar 18, 2011 2:16 pm
- Location: NEW SOUTH WALES AUSTRALIA
Re: G2 Clutch hub rebuild or alternative assembly?
Hi, What I did was mic the bore of the basket and the outside diameter of the hub and then calculator the clerance, the rollers are 1/4 x 1/4 and
then used oversize rollers, you can get •001" or •002". Remember that •001" oversize roller is •002" on diameter.
Cheers Wayne
then used oversize rollers, you can get •001" or •002". Remember that •001" oversize roller is •002" on diameter.
Cheers Wayne
-
- Posts: 14
- Joined: Thu Aug 10, 2017 2:16 pm
- Location: Jockland
Re: G2 Clutch hub rebuild or alternative assembly?
Good idea for the rollers - where did you get the oversizeds ones?
However - main problem is - if you imagine the clutch assy inner & outer face doen on bench with rear retaining place facing upwards - ok? Lift of the plate and you now have 3 different heights this plate must deal with - the inner hub the the roller cage sits on - the outer hub that then sits on the inner and the rollers themselves.
Thats whats happened here - all 3 are different heights due to crap design and wear. This appears to be the original hub and never been dissassembled either as all punch markings were still in position.
So - being a genious I took this along to my machinist after having to fing a piece of plate to machine then buying him tooltips - great so far. 4 days later - he screwed the whole damn thing up including the oem retaining plate!
So now totally screwed.
However - main problem is - if you imagine the clutch assy inner & outer face doen on bench with rear retaining place facing upwards - ok? Lift of the plate and you now have 3 different heights this plate must deal with - the inner hub the the roller cage sits on - the outer hub that then sits on the inner and the rollers themselves.
Thats whats happened here - all 3 are different heights due to crap design and wear. This appears to be the original hub and never been dissassembled either as all punch markings were still in position.
So - being a genious I took this along to my machinist after having to fing a piece of plate to machine then buying him tooltips - great so far. 4 days later - he screwed the whole damn thing up including the oem retaining plate!
So now totally screwed.
- Ozmadman
- Posts: 2651
- Joined: Wed Dec 14, 2011 1:02 am
- Location: ESSEX UK
Re: G2 Clutch hub rebuild or alternative assembly?
I think you are over thinking the whole thing, as Rob mentioned earlier, some play is normal and the clutch does wobble a little bit. That was certainly the case with mine but assembled it and put it back as it was and it has been fine with no problems.
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
-
- Member
- Posts: 8594
- Joined: Wed Sep 01, 2004 1:00 am
- Location: WEST SUSSEX UK
Re: G2 Clutch hub rebuild or alternative assembly?
Agreed.Ozmadman wrote:I think you are over thinking the whole thing, as Rob mentioned earlier, some play is normal and the clutch does wobble a little bit.
I'm not especially familiar with the Lightweight clutch with the cush inserts but in the H/W clutch the clutch rollers only roll when the clutch is free (disengaged). At all other times the whole assembly is turning due to the springs clamping the mainshaft, hub, plates and basket tightly together as one unit.
'There is a tide in the affairs of men
Which taken at the flood............'
Which taken at the flood............'