[mweisdorfer]

I was wondering what people thought of using an air gun to take the bolts off the various suspension parts and if you thought it was necessary to have one, or is it a luxury item?

I was thinking of this one on amazon.

http://www.amazon.com/dp/B00OK3TL8A/...I3942DLRMSRF84

I know the parts are made with aluminum or bolts that have some sort of special coating on them so they don't rust. However, I live in Michigan and we use salt on the roads in the winter. So, I am not sure.

A buddy of mine changed out shocks and struts on his Ford Taurus a couple of years ago and he spend $$$ on cobalt drill bits drilling out the bolts that snapped off as a result of rust and corrosion.

I know BMW uses better parts than FORD but I just have that experience in the back of my mind. UGH.

True the air gun would just snap them off anyhow.

What are your thoughts and experiences??

Please Advise...

[PhaseP]

In my experience air or other impact guns are less likely to break off frozen bolt heads than using breaker or cheater bars.

The impact hits shock the corrosion and cause it to shatter and allowing the bolt to unfreeze eventually. Corrosion and rust is like ceramic, they are brittle. The steel bolt has some elasticity to it, so it absorbs the impact hit to some level while rust breaks.

But if you load the bolt with constant increasing torque like using a breaker bar and leaning on it constantly, it yields and then breaks.

This is not to say impact guns won't break off bolts, they can. One should use judgement.

BMW bolts and hardware has a special coating, looks like the Geomet coating used on some the brake disks to me. It slows down corrosion but doesn't completely stop it.

The impact gun is a good thing to have, especially working on big rusty bolts on the suspension!

I have an Aircat 1000th, more powerful than the Dewalt you linked, used it without a problem on my car's suspension. Before this I was using breaker bar and a dead blow hammer for stubborn bolts, and what it used to take me half an hour to free them with the air gun started to take a few seconds.

Penetrating oil like PB Blaster is good help too.

And most importantly patience!!!

For smaller bolts I usually use a small 10 inch breaker bar and my palm as the hammer, or just a hammer if needed. For badly rusted smaller bolts that need more persuasion I use a 1/4" Dewalt 18V battery impact driver, has max 110 ftlb torque. A 3/8 smaller air impact would do same work, but cordless is much more convenient to use.

These days there are cordless 1/2 inch impact guns that have torque specs similar to 1/2 inch air guns. They are longer and bulkier than air guns though, but has the convenience of just carrying with you with nothing attached. They are also more expensive.

[PhaseP]

or is it a luxury item?

You decide based on this:

Badly rusted bolt needs to be taken out without breaking.
Without air gun, you take your breaker bar and biggest dead blow hammer, and start hitting the breaker bar to get it to rotate while the rust breaks away. You can swing one hit with the hammer every other 2 seconds, and the bolt will need 100 hits to free. It will take you 200 seconds if you work on it nonstop without rest.

If you had an air gun instead, it would be hitting 10 times per second on the same bolt. With it same bolt will come out in 10 seconds.
20 fold productivity increase!

In reality the difference will be like spending half an hour vs 10 seconds on that bolt, because you won't be as effective as hitting the bolt like the air gun does with your hammer and breaker bar.

[Efthreeoh]

Trust me, an impact gun whether air or electric, is far better than hand tools. They speed up disassembly tremendously. For example, breaking down the E90 thrust arms, with an air impact, you need not to hold the ball joint stud with a torx and use a wrench.

Also, as PhaseP has been saying, a constant torque load on bolt will break it. For example, exhaust bolts. Taking the pipe off of manifold flanges will usually end up with a snapped stud. With an impact, even the most stubborn nuts come off. Penetrating oil works well here to assist. I use Kroil; good stuff.

Go air my friend.

[Efthreeoh]

Do yourself a favor. Once you go air, get a butterfly impact wrench. You'll thank me later. Once you use it, you'll understand.