ES2 Clutch/main-shaft

I've heard tell of differing mainshafts but not personally seen the evidence. The most likely cause of chain alignment problems is the crank sprocket off-set. If you have a look at George Cohen's website, he shows at least three different types.

I struggled to fit a later AMC clutch into a WD16H chaincase (the later clutch with bonded back plate is a little deeper) and I was told at the time that mainshaft lengths do differ. The distance on a Doll's head box between the end of the sleeve gear and the clutch locating shoulder is 1 3/8" - How does yours compare ? I haven't got a Laydown box here but I can get someone to measure a mainshaft for you.

I've got a doll's head mainshaft here in front of me but I can't get my brother-in-law on the phone to ask him to measure a twin Laydown shaft so that I can compare.

The mounting bosses on the single engines are equidistant on each side of the crankcase centre line. I don't know about the earlier twins (I don't have one) but on the Commando the engine doesn't sit on the centreline of the frame - it's offset to the right by about 5/8" - Bearing in mind that the twin crank may be longer, this offset might result in the need for a shorter mainshaft rather than the longer one that one might expect.

I'm just thinking aloud here really but a twin mainshaft might be the explanation. With a bit of luck, someone with both types will be able to give the definitive answer.

Previously wrote:

I have a dilemma with the location of the clutch on the main-shaft of my 1950 ES2. The problem is that the clutch locates too far in (towards the gearbox) causing issues with the inner-primary case (someone has hacked this away to clear the clutch!) also, the engine and clutch sprockets are out of line by about 5/16". The gearbox appears to be mounted in the right place, so my initial conclusion is that the main-shaft is about 5/16" too short! Do they make main-shafts of different lengths (I can't imagine why they would)? Does anyone have any other ideas as to how this might have come about and how it might be sorted? My first thoughts were to make a 5/16" spacer to bring the clutch out a bit on the main-shaft, whilst this might work I don't think it's the way things were intended.

If it's of any help, the gearbox number is: GT101 1102

Gordon

Gordon- Hi- Unfortunately I've just recently mounted my inner chaincase on my 1950 ES 2 with laydown gearbox so I cannot check the lengths relative to the sleeve gear but as I do not have the clutch on as yet, perhaps these may be of some help. The distance from the outboard end of the mainshaft to the shoulder where the splines begin measures 1.071". The distance from the outboard end of the shoulder where the splines begin to the recessed face of the tin sliding disc that fits around the mainshaft measures .815"-I also have a 1956 Dommie 99 in large lumps and I can dig the gearbox out of storage and check it's mainshaft if this becomes needed- Hope this helps- Richard

Previously wrote:

Correction, that should be (1.06" and 0.80")

Gordon- I've just measured the distance from the backside (inboard) face of the clutch hub (center) along the splines to the stops on the outboard ends of said splines and came up with a distance of .765" plus or minus - if yours is greater this may explain the clutch seating in too far- I should also say that I have not had my clutch drawn all the way home by it's nut since my rebuild and therefor cannot vouch for my sprocket alignment as well but prior to rebuild the alignment was fine and I have not replaced any of the components in question. It seems a spacer turned up on the lathe that seats between the shoulder on the mainshaft and the stops on the clutch hub splines would solve the alignment issue but this would lesson the amount of spline engagement and thread engagement on the clutch nut and frankly I am not knowledgeable enough to say if this would become a weakening issue-perhaps some other member could answer this. Again I hope this will be of some help- keep me posted-Richard

Previously gordon_smith wrote:

Richard,

Thanks for the information on your clutch. Just measured the equivalent distance on my clutch and came up with 0.71". So, I'm now inclined to think that the main-shaft is too short by about 1/4" or so. However, it looks as if I could still get a full-nut on the shaft with a 1/4"spacer fitted, so I may take that option. The alternative would be to fit a replacement main-shaft and I guess that could prove expensive (assuming I could find one)!

Gordon

Hi Richard.

I have a similar issue where I am attempting to marry up a dollshead gearbox on a 1936 ES2 with a later engine from a 1958 ES2. The problem is that the clutch goes too far in on the gearbox mainshaft meaning that the clutch sprocket does not line up with the engine sprocket.

I was wondering if you did solve this issue with a longer mainshaft in your gearbox? I don't think the spacer option behind the clutch would work for me as I wouldn't have enough thread left for the nut that holds the clutch in place.

Any advice would be welcomed.

Thanks

Peter