QuestionFirst of all good morning(or evening), thank you in advance for your answer and excuse me for my English.I have a problem with fitting the crankshaft in the crankcases(Honda c50).(I will use the termin 'nests' meaning the place of the crankcases where the bearings of the crankshaft must enter).Well, the nest are a bit small so in order to fit the crankshaft in the crankcase(the bearings into the nests) I must hit the crankshaft with a hammer. But doing so, the bearings are a little bit ,let's say, 'destroyed' and the cranshaft has a small play(very small)but existable, which results vibrations. What can I do to fit the crankshaft into the crankcases whithout using a hammer? Should i warm the crankcases, and maybe freeze the crancshaft?
May be I should tell you that the problem appeared after 'reconstruction' of nests in specialized shop ofcourse, which had as a result the nests to become a little (very-very little) smaller.
AnswerHi Panagiotis.
The problem is the new bearings are the wrong size. The bearings that go in there are designed to fit tight. Thousandths of an inch tight. They are very precisely measured and if they are not exact with the original parts then you will have problems.
In this case, using anything other than OEM (Original Equipment from Manufacturer) parts could result in problems later. It may be years later, but the parts should still not be anything but OEM. In this case, you should be okay with what you have in there.
You will need to heat up the bearings and the case around them to about 300-400 degrees (Farenheit) and freeze the shaft.
If it moves like it should after everything is assembled and at room temperature, then you should be okay with it.
By the way, most tight fitting parts, like that are press-fit using machines, but can be done, in the manner that I previously described, by hand.
Good luck.
FALCON
