Hi guys
My bsa a65 1967 cases I've tried to install crank but when I go to secure the case together the crank won't turn, I've measured the old timing bush which is 96thou flange and my new bush is 109 thou my thrust washer is 62 thou all new parts , this is installed without any shims in, only the shim cup is in place any ideas
Do you think I should milk the new bush down to the original bush or is the new thrust washer to thick
firstly, is the roller bearing pushed right in to the shoulder.
then as you have measured , you have a 13thou difference between old and new flanges. When I rebuilt the B40 the timing side locked the crank up on assembly of the middle case. skimming by 4 thou made a small difference so another 4 thou skimmed off the face gave sufficient clearence and crank rotates free now. bearing in mind , there would have been some wear from use I would not go straight for the 13 thou but take a bit at a time.
can you measure across crank faces? then measure depths from case faces to bearing and bush face. this will give the base dimensions.
one other thing, was the timing side bush pressed in square?
It would be interesting to know what shim thickness was used previously, if you still have them. Best approach is to check the LH bearing and the RH bush are fully inserted and then work out the current free play (probably -ve) via the measurements suggested although these can be hard to carry out to the required accuracy (1 thou) without the right equipment.
Otherwise a good starting point is probably to skim off 109 - 96 = 13 thou - thickness of original shims.
Yes the shims should be 13 thou if you go by the numbers on crank and cases, but obviously cannot be fitted at this stage, I don't have accurate equipment to the crankcase distance, I'll make another check to see if the bush is in correctly, might drive it out again and refit it
I did see a you tube post were the guy had the same problem and he refitted the old thrust washer back in and he go the correct play but I don't have the old washer so can't do that
Is that a coincidence that the original shims were 13 thou and the new bush flange is 13 thou wider than the original? Assuming both bearings are fully inserted into the crankcases, it looks as though 5 thou off the bush flange should give you roughly the correct 5 thou free play on the crankshaft?
Just looking into this a bit deeper, it's possible you have an earlier bush (68-0015) which has a wider flange than the later 1966+ bush (68-0657). It seems that a good way of measuring the end float of the assembled crankcases is by putting a dial gauge on the end of the crankshaft and then levering the shaft sideways to measure total movement. It looks as though the ideal end float should be 3 thou although this needs to be double checked.
Hi guys
I knocked the new bush out and noticed that it didn't go in square so I adjusted it and got a clearance
Now the camshaft is tight so have to ream it with a 13/16 reamer but still tight, so have to investigate