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Oct 19, 2016 6:50 pm
Oct 19, 2016 6:50 pm
Subject: Re: G9 gearbox
Adam, if you are going to strip the gearbox completely I found that there were 2 vital things in my humble opinion. There may be better advice on this Forum from others but ...
1. Renew the bronze bush in the middle of the main shaft (between the output and the input shafts). Any play in this bush is likely to cause the gearbox to jump out of gear on occasions and will also put sideways stress on the helical gears (hence broken teeth)
2. On the mainshaft make sure you get the helical gear off the steel "collar" (for want of a better word) that it has been pressed onto. It was not immediately obvious to me that the "collar" was not in fact part of the gear itself. However after looking at it very carefully I realised that there are various holes into which you need to insert some hardened steel pins in order to push the gear off the collar. Some heat might be needed. When you get the gear off you will find that there are oil holes and pathways hidden underneath which have no doubt accumulated crud and carbon over the 80 years or so. The holes in mine were completely and solidly blocked. The blockage of these holes prevents any real lubrication reaching the bronze bush in the middle of the mainshaft and will cause wear to this important bit of the gearbox.
It is difficult to describe all this accurately but checking how oil can get to this bronze bush in the middle of the mainshaft should be more obvious to you when you get the gearbox apart !
Adam, if you are going to strip the gearbox completely I found that there were 2 vital things in my humble opinion. There may be better advice on this Forum from others but ...
1. Renew the bronze bush in the middle of the main shaft (between the output and the input shafts). Any play in this bush is likely to cause the gearbox to jump out of gear on occasions and will also put sideways stress on the helical gears (hence broken teeth)
2. On the mainshaft make sure you get the helical gear off the steel "collar" (for want of a better word) that it has been pressed onto. It was not immediately obvious to me that the "collar" was not in fact part of the gear itself. However after looking at it very carefully I realised that there are various holes into which you need to insert some hardened steel pins in order to push the gear off the collar. Some heat might be needed. When you get the gear off you will find that there are oil holes and pathways hidden underneath which have no doubt accumulated crud and carbon over the 80 years or so. The holes in mine were completely and solidly blocked. The blockage of these holes prevents any real lubrication reaching the bronze bush in the middle of the mainshaft and will cause wear to this important bit of the gearbox.
It is difficult to describe all this accurately but checking how oil can get to this bronze bush in the middle of the mainshaft should be more obvious to you when you get the gearbox apart !