Straightening a 2011 BMW Z4 N54B30 Crankshaft

This video shows the straightening process using the peening method. Crankshaft was bent approximately .013 from two failed rod bearings on cyl #1 and #2. This needs to be done before grinding.

[@davidwiggins3451]

When you said you were going to use a chisel on the crank, I thought for sure you'd be striking a counterweight and not the rod journal. Amazing process.

[@kirkc5823]

Very interesting, my learning moment for the day.

[@robfrost1]

Great video, thank-you for demonstrating. Why do you only hit it on the left hand side of centre?

[@Gregstukey]

this is great. would love to see one on cold straightening a propshaft. we normally send them out but would be better to be able to do in house.

[@gabrielh5937]

Would 3 thousandths TIR cause binding on main bearings. Clearances seen ok

[@LakelandAutoMarine]

Probably not. .003 bent isn’t huge. Maybe the main bores themselves are too tight or not in alignment?

[@jorisdeckers2270]

Nice job ,why do you not use hydraulic press?

[@LakelandAutoMarine]

Peening stress relieves it. If you use a press it will spring right back like you never hit it.

[@jorisdeckers2270]

@@LakelandAutoMarine also I have seen that the push the shift and tapping it then?

[@robfrost1]

Where he hits it down, he's making it come up.

[@gabrielh5937]

How much do you charge to straighten a crank.

[@LakelandAutoMarine]

Depends on how bad it is and how far out it is. It’s time and materials.

[@jorisdeckers2270]

Also don t you heat the shaft

[@LakelandAutoMarine]

Nope.

[@jorisdeckers2270]

@@LakelandAutoMarine I read a article from caterpillar ,they say you should heat the crank to about 100 to 200graden Celsius before making it straight?