Hi,
I'm clearly being really stupid here - as no one else sems to have asked this question:
I have stripped my Dommie 88 engine down, and am trying to split the crankcase halves to check the bearings. The driving side has pulled away nicely from the roller bearing, but I can't remove the driving side crankcase half as the con-rod hits the web. Clearly I need to remove the timing side half first. Trouble is the crank is not coming away from the timing side crankcase half. My Norton manual says "the timing side crankcase can now be removed by levering gently between the crank cheek and the crankcase inner wall using a tyre lever or similar tool"
Is that really how you do it??
Thanks, Aston
The timing side ball bearing…
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Advice
Don't use a lever anywhere inside / outside the cases if you want to avoid bending / breaking something.
My first thought on this issue being that you had not removed the Timing side crankshaft gear and oil thrower. Send a photo of the Timing side please.
Also, you must have an early Model 88 for it to still have the strengthening bar across the top faces. This was a pain in the cases to anybody stripping down or rebuilding a Model 7 or early model 88. It just gets in the way. Later engines do away with this crankcase feature and many engineers just cut it off to help make a rebuild much easier.
Once the Timing side is clear of all the gears and pinions, some heating of the ball bearing housing will allow the crankshaft to be pulled out taking the bearing with it.
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Drive side crankcase removal
I have just rebuilt my Model 7 and early Model 88 engines, both of which had the rib across the drive side crankcase.
If you remove both top crankcase studs first you will find it easy to lift the drive side crankcase over the top of the small end as the roller bearing will clear the drive side crankshaft.
Just clean the stud threads and ensure they tighten up after replacing the drive side crankcase on assembly. (Add a drop of Loctite 243 if you like).
By fitting the crank assembly into the timing side crankcase first there is good supprt for refitting the drive side crankcase.
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Thank you.....
Thank you John; Philip and Ian for your replies and advice. Very much appreciated.
I would firstly like to thank Philip for his post and photos on 4/5/2019 which enabled me to modify my 067524 puller so that it worked and I could remove the half time pinion from the end of the crank. I bought a replacement backing plate and modified the puller "legs" so that they fitted on the plate as you showed in the photos. I found that a good quality draw file was good enough to modify the tool - and with a bit of heat from a heat gun - off came the pinion! Everything is off the timing side - photo is attached. Very interesting - your note on removing the web. As for the "earliness" of the engine - this was a replacement (#36521) fitted in 1960. ??
And yes, thanks Ian. I wondered about removing the two studs, but didn't particularly want to try turning the shanks with mole grips, now the cases are splat in two. The nuts were pretty tight and the studs gave no sign of moving originally.
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The timing side ball bearing is an interference fit both on the crank and into the cases, the driveside has the roller which comes apart easily as shown in your pic. What I have done rather than try and prise the crank out of the ball bearing is to heat the timing side case until water spits on the case and then lifted the driveside case plus crank with ball bearing out of the timing side.
Heat the whole of the timing side case not just around the bearing or the expanded aluminium around the bearing will push against the bearing even tighter as the cold surrounding alloy does not expand.
This also has the benefit of insuring you do not accidentally drive a cold ball bearing out of the case and risk losing the interference fit in the case.