I was told NOT to uses a impact gun on the crank pully is this true??

[sclark]

Hello

I was

Topic

[johnzcarz]

Quoted From TexasCoder:

Somebody correct me, if I am wrong, but as long as the vehicle is in gear, Park for automatics, or 1st for manuals, nothing is going to spin (ie: connecting rods).

I don’t know what your mechanic is talking about, he must have had a bad experience one time, or a good reason for telling you that.

I agree. The crankshaft is a lot more likely to turn when you have a breaker bar + cheater pipe on there trying to break the bolt free than when using an impact. Seems the impact would actually be a gentler way because it applies and removes force in quick busts – that’s why you can remove bolts in pulleys/idlers so easily whereas the pulley would just spin if you used a wrench.

But even so, you are going to turn the crankshaft anyway to set valve lash, check piston to valve clearances, etc.

[sclark]

hummm good point unless he is thinking it moves alittle bit even when its in park and puts stress on the bearing? hummm iam not sure

[ytram]

I have actually seen this in service repair manuals on some cars. I have used impacts and never had a problem either.
Chances are you will do more damage to other things tugging on a cheater bar and wedging some thing in flywheel ring to break bolt loose.
I have seen Kilmer crank the engine with a breaker bar in place to break it loose. Now that I would recommend against that!

[Author]

Replies