Best onboard impact wrench

1/2" with 1200 ft lbs would work well. Anything 1000 ft lbs or better would work good on big truck lug nuts. The only problem is you would have to take it slow for your air compressor and tanks to keep up with repeated use. So a 1/2" would be a good choice because of the lower scfm compared to the big boys. You can find alot of good deals on air tools at pawn shops. It seems like everyone pawns air tools. If you never dealt with pawn shops, always ask their bottom dollar and you can get the marked priced knocked way down. I like Northern Tool also.

 

I use 1" IR impact wrench with a 1/2 hose. It works very well. 3/8 hose restricts air flow and your tool is not going to work properly. Make sure you use a right size quick connector at your air tank so there is no air flow restriction there.

 

I wouldnt use anything less than a 3/4 drive impact. 1/2 hose preferrably but you can use 3/8 if absolutely necessary. Dont mess around and try to shortcut though. I have seen a couple sets of duals come off already and dont care to see anymore

 

You need an impact that uses the least amount of air in volume with the highest torque rating possible. I use an Ingersoll Rand 2141 3/4" drive

This impact wrench uses a small volume of air(CFM) for the breaking strength it has in reverse. If you plan on using your air supply on the truck, you'll also need to buy 1/2" diameter air hose to supply enough volume(CFM) at the gun to have the driving force to remove lug nuts. You'll have to have a 1/2" fitting in the tanks to hook the hose up to. The gun I listed has a titanium impeller for the extra torque strength and low air volume usage...........it's not a cheap gun, try tooltopia.com for the best price on it.

If you purchase a cheaper gun with a standard impeller, it will use more air in volume and may not work well doing lug nuts while using the truck for an air source.


http://www.tooltopia.com/ingersoll-rand-2141.aspx

 

Good advise on using a larger hose. The best gun is worthless if it can't get the proper amount of air.

Here is the gun I use and have been very impressed with. For not being a high dollar gun it has performed as well as our 3/4" when taking my wheels off.

http://www.northerntool.com/shop/tools/product_200400363_200400363?cm_ite=100107&cm_pla=Air