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

[sclark]

Hello

I was

Topic

[sclark]

he was saying taking a bolt out to he told me DON’T do it i don’t know it don’t make sense BUT on the other hand if there is not enough oil on those bearings i could see it hurting them so i dont know..lol

what yall think??

[Trcustoms719]

That does not really make sense to me.
It is not a good idea to just run the bolt in with a impact without using a torque wrench but ,removing the bolt with one should be fine.

[3SheetsDiesel]

I take crank bolts out with an impact all the time. You can’t really spin a crankshaft using an impact gun, at least not by the crank bolt. There’s no feasible way that I can think of to damage the connecting rod bearings by spinning the crank with the engine off. Besides, if turning the crankshaft with the engine off would damage the bearings, how would you ever line up the timing marks? Would you just take off the timing covers and have a helper keep bumping the starter until it kicked the engine around until the marks lined up? That could take forever and a day to get right, if it ever happened.

[college man]

no harm will happen taking the crank bolt out with an impact gun.

[TexasCoder]

Hmmm, interesting question.

I have always used an impact to remove them, but to put one on, always use a torque wrench.

Heck, there have been times that without an impact and blow torch, I would NEVER have gotten some bolts removed…I have nightmares about my cousins Pontiac Bonneville SC. 🙂

Putting one on with an impact could damage the hydraulic dampened pulleys out there, but I am more concerned about what the mechanic was trying to convey.

Can you ask this mechanic to explain a little more in detail? Was he referring to taking one off or putting one on?

[sclark]

taking it off he said it will make the connecting rod bearing failure Prematurely and this is because there is not enough oil on those bearing cause of course the engine is not running to make oil pressure…

it kinda makes sense but it dont if that make sense…lol

[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.

[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

[Matt]

The engine is free to turn when a car is in park. The torque converter is a fluid coupler. It will not engage the transmission with only a few hundred rpms. Otherwise, how would you start the engine? You don’t put it in neutral. That’s why you have to push in the clutch or put the car in neutral on older model standard trans cars/trucks that don’t have a NSS.

[dreamer2355]

I don’t think your friend understands how an impact gun works unfortunately S:(

You will be fine removing the bolt with an impact gun. Just make sure you torque the bolt down to specifications as suggested already.

[TexasCoder]

Quoted From Beefy:

The engine is free to turn when a car is in park. The torque converter is a fluid coupler. It will not engage the transmission with only a few hundred rpms. Otherwise, how would you start the engine? You don’t put it in neutral. That’s why you have to push in the clutch or put the car in neutral on older model standard trans cars/trucks that don’t have a NSS.

And that is why this forum is AWESOME! Thanks Beefy, very very good point…there you go again with stating the obvious for me 🙂

[Bad_dude]

I wish I could use the impact gun. I have an electric one but I can’t use as I don’t have a garage. If I use an extension it would extend all the way across and when a car drives by, the cord gets rip off. So I can use impact hands.
Every one has their own preferred methods, but the ones that get the job done easier are the ones we should all use.

[EricTheCarGuy]

I’ve never heard of that or experienced any problems in taking crank bolts off with an impact so I would have to disagree with that statement. I believe I understand the logic behind that claim but as far as I know it’s never caused a problem with any of the crank bolts that I’ve ever removed.

[sclark]

thanks guys you all have made good points so with that said the finally answer is:

its ok to take the bolt off with impact gun of course dont uses one to put the bolt on cuase it has to be torque to spec

thanks guys

[Author]

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