Hello, I posted it a few weeks ago, the clearance of my crankshaft between the main baerings is about 0,5mm (0,019685). I know, that's to much. My question, does exist some distance discs for crankshaft? So that can minimize the clearance? Ask Wolfgang
Wolfgang, The proper name for them is "shims" and yes they can be used. Since you need to go from 0.019 thousanths down to about 0.002 using shims is not an option. If you put shims behind the bearings you move them out of the locking tab and they will turn. The term for this is a "spun bearing" and that is bad news. The way shims were used was to pour a bearing that did not have enough clearance and then use the shims where the main cap mates up to the block till the right clearance was achieved. You could maybe polish 0.001 off of the crankshaft and then use a 0.020 bearing which can be bought from a number of suppliers. It's hard to keep things straight when using a polishing belt so if it were mine I would have the crank mains ground to 0.030 and use that size bearing---also easy to find. On super rare engines we have poured babbit bearings to the thickness needed and then honed to the existing size of the crankshaft. How much is the freight and import duties on a 235 crankshaft? They are easy to find and might be the better way to go.
Yes. I talk about the thrust bearing. And I haven't space between the main bearing cabs and the baerings, rather clearance axially between the thrust bearing and the crankshaft. And its about, so told me the worker of the engine shop, 0,5mm = 0,019" . And if I understand the work shop manual right it must have max. 0,0078". So my question is, is the crank off or does give rings that minimize the clearance?
Have never seen any for a 235. Back then they welded up the worn area and then ground it back to standard size. In my experience one usually had to grind the crank 0.010 after welding due to warpage. If you google "weld thrust bearing surface on crankshaft" there are many crank grinders that still do this.
Evan: A mechanic I knew in a previous life told me that the thrust surface on cranks were worn down more quickly by spending a lot of time with the clutch depressed. He said that if you were waiting for a traffic light to change, you should always put the tranny in neutral and let out the clutch. This would also reduce wear on the throwout bearing and the driver's left leg. Down side would be the idiot behind you honking as soon as the light changed, before you got back into gear. If what he said was true, most of the crank wear would be on only one of the crank's thrust surfaces.
I saw, that rockauto. com sells new crankshafts for this engine. I think, I'll buy one and a new set of main bearings. Wolfgang
