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Workshop => Engine and Bottom End => Topic started by: JoePA on May 23, 2014, 10:04:10 AM

Title: LT50 crank rebuild??
Post by: JoePA on May 23, 2014, 10:04:10 AM

The kids LT50 decided after 30 years and 8,000 laps around yards the crank bearing decided to call it quits. This seems like an easy fix with a press. Only thing I'm worried about is getting the crank trued. Any tips or advice before I attempt to take on this task?

Title: LT50 crank rebuild??
Post by: Jerry Hall on May 23, 2014, 10:24:22 AM

Quote from: JoePA;34637

The kids LT50 decided after 30 years and 8,000 laps around yards the crank bearing decided to call it quits. This seems like an easy fix with a press. Only thing I'm worried about is getting the crank trued. Any tips or advice before I attempt to take on this task?

Do not press the crank-pin from one side all of the way through the other side.  The crank-pin is damaged where the connection rod and bearing makes contact with the crank-pin.  The damaged crank pin will damage the precision hole in the crank-web when a damaged crank-pin is pressed through it.

Crank shafts are sent to us every week where someone was trying to save us some time and themselves a few dollars by pressing their cranks apart without having the fixtures to press the cranks apart.  We have to throw most of these cranks in the scrap pipe because a damaged crank pin hole will not true up to spec and or will decrease the interference fit.

Title: LT50 crank rebuild??
Post by: Bowtie316 on May 23, 2014, 10:30:23 AM

I like to do everything myself, but this is one job I send off to have done.  I have seen a few messed up by friends trying to do it themselves.

Title: LT50 crank rebuild??
Post by: JoePA on May 23, 2014, 10:42:42 AM

So what does it usually cost to have something like this fixed?

Title: LT50 crank rebuild??
Post by: Bowtie316 on May 23, 2014, 11:29:23 AM

I had to do a lt80 crank a few months back, was quoted $75 labor to install new rod and bearing.  I ended up just buying a new crank because mine was rusted badly.

Title: LT50 crank rebuild??
Post by: JoePA on May 23, 2014, 11:43:02 AM

hmmm. I think I'm going to try and rebuild this crank. If I mess it up...oh well I learned something but I'm pretty sure this is doable. don't learn unless you try.

Title: LT50 crank rebuild??
Post by: Bowtie316 on May 23, 2014, 12:00:00 PM

It would be helpful to know what the jig looks like. I haven't spent any time on google looking but would assume it would be a round sleeve or something to keep the counter balancers square and in line while you press together.  Might be able to use some sheet metal and some clamps, idk.  Definately check the runout and don't put it back in the motor until it's right.

Title: LT50 crank rebuild??
Post by: JoePA on May 23, 2014, 12:29:15 PM

As long as I don't mess it up like Jerry said I should be OK. The runout is where I'm worried as if I remember correctly on that crank you can hit it with a deadblow to move it. I could be wrong. If it fails...Oh well I'm out $18 and looking for a good used crank. Ken OConner has some great video's on the rebuild process for crankshafts.