I remove the old bushes with a suitable shouldered drift as Ron describes...That and a hammer as I don't have a press at home...
If the bushes that are being supplied are bronze they may well need reaming to size after fitting....
One problem you may also encounter is the drilling of the lubrication holes in the inner bush..These are a small diameter and at an angle to the axis of the bush..There is a high chance therefore that the drill will snap when it breaks through, particularly if you are using a hand held pistol drill...
Another consideration is the amount of wear you have on the main shaft...Many are undersize but they can be reground to provide a clean, true surface as they are hardened all the way through. In some cases stoning is enough to remove irregularities...Undersize bushes will then be required...
Generally, for that reason, I manufacture my own bushes to suit the shaft condition but that aside the procedure I use is as follows...
First remove the old bushes..Next, using a suitable drift fit the inner bush (the one furthest from the clutch)..Now, using a suitable size drill, drill slightly into the surface of the bush using the lubrication holes in the gear as a guide..Then remove the bush and drill each of the (now) marked holes through with a larger drill...say 3/16" diameter...Refit the bush to the gear taking care to correctly align the oil holes...Then fit the outer bush to the gear and finally ream/bore both bushes to the finished size as required..
The main shaft diameter when new should be .872"-.873"...Finished bush clearance should be .0015"-.0035"...I try to aim for the lower figure..If you choose to manufacture bushes a bushing bronze such as PB1 is a suitable choice....Ian
I have always prefferred LG2 to Phos bronze because it is too hard for my liking.
Replacing the bushes more often is the lesser evil of doing a bushing and a main shaft less often.
Apart from that I have a good supply of 85-5-5-5 in a few sizes and it machines a lot better than any PB .
Thank you so much for all this valuable information - I don't know any other place I could possibly have found such expertise. I know you've saved me from making some very silly errors! I can now proceed with more confidence, and I hope more competence.
