What do i need to split a crankshaft? How hard is it?

so i bought a 1978 yz400 and i would like to re-build the crankshaft.  ive done a little research and i need a

 

press and some other stuff.  i dont need like a walk through on how to do it, i would like to know just HOW hard

 

is it to rebuild a crank, what are some things i should look out for and any other general tips i should know.

 

how much would a press be, and would it be really tedious?? i know from what the manual says it is really hard, should be 100% aligned and not even 1% off   but i would like to attempt to try and rebuild it.

 

i know there is a machine that will somehow press the crankshaft apart, how much would it be??  

 

could this machine (im not quite sure what its called other than a crank press) also press it back together??

 

What is the likelihood that i will mess it up and ruin the entire engine?? 

 

:thumbsup:   i am mechanically minded, and i have a manual for it, so i will make an attempt on it...maybe   :p   and i dont want to bring it up to a shop cause they would charge me probably 6 to 700 $$$$  WAYYYY more than i want to spend! 

 

 

thanks!!

  

 

Edited by kyle5647

A mechanically minded person knows that you obviously can't split a crankshaft without ruining it. I think what you mean is splitting CASES...as in case halves. The crankshaft merely needs new bearings installed. There are 1000 topics on this, as well as videos on youtube. Not really a terribly difficult job.

And if you do mean split the crank, then that is definitely best left to the professionals. You would need a truing stand with two dial indicators, and years & years of knowledge to be abe to get a crank "trued".

A mechanically minded person knows that you obviously can't split a crankshaft without ruining it. I think what you mean is splitting CASES...as in case halves. The crankshaft merely needs new bearings installed. There are 1000 topics on this, as well as videos on youtube. Not really a terribly difficult job.

You do split crankshafts. How else can you change the rod and rod bearing?

As said, huge amount of skill in doing this. Requires a press, truing stand, dial indicators, dead blow, and a lot of skill and patience. I worked in a shop that would rebuild cranks, it is not a simple job.

Prices for crank rebuilds arent bad. I've found most places charge less than $100 labor. Trick is to find a local one so you aren't shipping

I'm not sure what need trued with your crankshaft....do you know its bent?

Edited by 97wr250

I'm not sure what need trued with your crankshaft....do you know its bent?

When you change the lower rod bearing and rod you must true the crank after pressing it back together. You aren't bending anything, just getting the pin and webs aligned.

I see what you mean now, sorry. Just a terminology difference. Sounded like something totally different to me.

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