I'm considering buying an impact wrench. The one I'm looking at says it has 250 ft. lbs at 90 PSI. My question is whether the cheapo compressors (e.g., Home Depot has one now for $99 bucks that purportedly will go up to 135 psi) will really do the trick. Anyone have any experience with this? I rarely need an impact wrench, but would like to have one for small jobs. At the moment, I'm trying to get that pinion nut off the differential.

A compressor with a motor that that can be wired to run off 110 or 220 volts single phase is good. A 1 HP, 3450 RPM motor pulls around 18 amps on 110 volts. This pretty well loads up a 20 amp circuit and will dim the lights when fully loaded. On 220, the amp load is cut in half. I'm not so sure the 250 ft-lb impact wrenches have that much torque in reverse and that's where it counts. Mine takes forever to break loose a 90 ft-lb lug nut. WW Granger offers decent compressors at a reasonable price (good price to quality ratio). They have an on line catalog that shows all the specs on the different models. Replacement parts are always available but the only thing I've needed in 15 years is a filter. It takes more volume (CMF or SCFM) to run a spray gun than an impact wrench. Sooner or later, you will spray paint something (car body, fence, deck, garage). You don't want to stand around waiting for the compressor to pump back up. jp

I would just get a good quality electric impact wrench. For the occasional mechanic this is a valuable tool. After I saw a old Volvo Master tech use an ancient Rockwell electric impact wrench to remove the pinion nut on a 140 in a nanosecond, I borrowed his and to do my own 140. Later when I needed to do the 245, I bought a Dewalt 1/2" drive at Home Depot for $125. Done much faster than air tool set-up.
In order to do this right with air impact you need a sizeable investment in a large capacity compressor and air tank.
--
'89 245 Sportwagon, '04 V70 2.5T Sportwagon

I will have to agree with vvpete. The cheap bottom line air impact drivers are rated VERY optimistically. A quality electric impact ( Dewalt, Makita, Millwaukee, Porter Cable) for the occasional user is a better deal, and a better tool.

I beg to differ.

Before I got my compressor, I bought the top of the line, 250lb/ft DeWalt. Wouldn't even remove lug nuts.

My 250 lb/ft Craftsman air impact does it just fine.
--
'73 142, '75 242, '75 245, '80 245, '83 244, '86 244, '87 745T, 92 244 (for sale)

It'll work fine. For taking off four tires you don't really need that much volume. If you were in business to do this it would be a different story.

DEWFPO
--
1998 S90 070,050 and 1995 964 153,010

The $99 compressor will work fine with an impact wrench. However, I wouldn't recommend buying one of those compressors with the little 1.5 gallon tank. You will soon get addicted to pneumatic power. I bought a compressor to mostly to inflate tires, but I now have an impact wrench, air hammer, cut-off wheel, air ratchet, sheet metal shear, recip saw, two angle die grinders, and two paint spray guns. Air tools are much cheaper than their electrical counterparts.

If you're on a TIGHT budget, you may want to check Harbor Freight for their prices.
--
'88 244GL, '89 244GL, '90 244DL, '91 244, '92 244

Hello. My name is Art. I have an air compressor.
--
Art Benstein near Baltimore

Actually, I can quit anytime I want. Yeah, anytime. It's just that, well, I choose not to. The hum, the hiss, the BUZZ of those little tools helps me to relax, and... socialize. I can quit anytime I want, I tell you...
--
'88 244GL, '89 244GL, '90 244DL, '91 244, '92 244

Oooh, the BUZZZZ! Yes. So much better than electricity.
--
Art Benstein near Baltimore

A cheaper alternative is to make a third hand. A long piece of 1/4"x2 1/2"x2 1/2" angle iron with two holes drilled for two of the bolts on the flange. You may need to grind a little clearance for the socket depending on where on the angle iron you place the holes. Buy a piece about 4' long and it can be used for many many jobs depending on the size and placement of holes.

Bolt it to the flange and use a Looong cheater bar on your 1/2" breaker bar.

I've punched loose 250+ lb-ft assemblies this way (using a 3/4" breaker bar... the 1/2" twisted off!).

Mike!

It's not only the pressure, it's also the volume of air the compressor puts out. The cheapo compressors just don't have the SCFM@90lbs to do the job. For occasional jobs I'd look at a good quality electric unit.

If you can swing the ~$375 for a good 5.5-6hp upright unit you will find many uses for it and wonder how you ever lived without it.
--
Dave Shannon
Spring Valley, California
'84-245T 190K+
'88-240 190K+
'65 1800S ????K
'73 1800ES 117K
'92 745Ti 150K
Jeep Wrangler Sahara 10K
my pages

I agree with that. I have set up a shrine and leave offerings to my compressor.
--
Simon 80 240 300k 17 years. 'White Lightning'

A 1/2" drive impact gun is a real toy. I don't use mine all that much but I invested ina good one.

Also The Tank size on the compressor is what is important. Most Compressors with Tanks will be able to get to 135lbs. If you have a compressor with a small tank (13gallons for example) you wont be able to take off a tire without waiting for the compressor to catch up.

I just bought a 60 gallon, Oil type compressor and the Snap on IM6100.
I hope some of this helps.
Listed below is MAnufacturer,Part number, Ft lbs of torque in foward and FtLbs of torque in reverse.


½” Impact Drivers


Ingersoll Rand IR2135TI 625ftlbs Forward 700ftlbs reverse approx $250

SNAP ON IM6500 575/650 (there best new gun)
SNAP ON IM6100 550/625 8500/1300blows $160

SNAP ON IMC500 525/620


Ingersoll Rand IR232-tgsl (thunder gun) 600/700 10000/1200 approx $126

Ingersoll Rand IR 2131 450/600 $184

Ingersoll Rand IR 231-H 450 $118

Ingersoll Rand IR 244 500/500 $180

SNAP ON (Blue Point) AW525

Chicago Pneumatics CP741 600 $170

Chicago Pneumatics CP749K 625 $174

Chicago Pneumatics CP7750 650 $199

Mac Tools AW4400 625/800 $270

Mac tools AW434 ?????

Blue Point AT650 550/600 (746/813)

Blue Point Blue Point AT555A 474/550 (644/745)

AIRCAT 1404BG 640/640 7000/1100blows (shelby_clemons@hotmail.com) $110 shipping included

3/8 impact wrenches

Snap on FAR720 65lbs
Ingersoll rand IR109XP 70lbs


--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

It is not so much the compressor as the actual wrench. the higher priced wrenches will have much higher torque ratings. Up to 450 Ft/lbs The cheap 250 ft/lb wrench I have will do the job most of the time.
--
Simon 80 240 300k 17 years. 'White Lightning'

Thanks for all the info. I won't be going with the cheapo compressor, although I do think a 250 lb. wrench is all I'll need.

from experience I can tell you that even a 350 lb torque impact wrench is not always up to the job. That's what I have and on occasion i need to borrow the 450 from the garage across the street. As far as compressors go it is really about how hard you are going to use it. A cheap one with a small tank is going to cycle on and off alot but 90 psi is 90 psi and for the short burts needed to loosen a nut the cfm doesn't really matter. CFM is about running air tools non stop, like painting etc... That being said I have a big compressor wiht a big tank and enjoy using it for many different tasks, for example, if you are using it to tighten a spring comppressor the extra volume is a real benifit, as this requires constant running of the impact wrench.