Air impact wrench - how much CFM for axle nuts?
#1
Registered User
Thread Starter
Air impact wrench - how much CFM for axle nuts?
I started the axle replacement tonight but didn't get too far. I can't get the axle nuts to break loose. I tried w/ a 25" breaker bar (3/4" drive) and couldn't get them to loosen so it looks like I'll have to rent an air impact wrench. What CFM in the compressor and the wrench will I need to get the nuts loose? My compressor is a 3HP 20 gal that puts out 8.1 CFM at 40 and 6.1 CFM at 90. Wondering if I'll need to rent a compressor too.
#2
Registered User
Yea you will need some serious balls, I too just did the axle change (left side) I broke 2 breaker bars and 2 ratchets. Then I decided to apply my torch to it and hooked it up to my compressor 8 gallon and it wasn't enough with my brand new craftsman air impact. I then pushed MY00 down the street to my buddies house, hes got an huge industrial air compressor and it too struggled, its got to be at least 40 gallons. I reheated the 36mm nut and put my impact gun back on and it came right off but let me tell you it was a mission for me..
#4
Registered User
Thread Starter
i might put the handle of my floor jack over the breaker bar and try that. If that doesn't work, I'll try to rent an air impact wrench. The rental looks cheaper than buying a 4ft 3/4" breaker bar, esp. since that's the only use I have for a bar of that size.
#5
Wow it sounds like those were really on there if those breaker bars didn't work. 4ft sounds a bit too much.
Anyway to bust those off it sounds like your compressor is already good, 8.4 CFM is really good. I was looking to order a strong impact gun also from Matco. The one I looked at has 780 ft/lbs @ 5 CFM. So obviously your compressor will work just fine. Just remember to put a couple drops of tool oil down your air lines so it doesn't mess up your tool.
Anyway to bust those off it sounds like your compressor is already good, 8.4 CFM is really good. I was looking to order a strong impact gun also from Matco. The one I looked at has 780 ft/lbs @ 5 CFM. So obviously your compressor will work just fine. Just remember to put a couple drops of tool oil down your air lines so it doesn't mess up your tool.
#6
My ingersol-rand gun zaps them off with ease and my compressor is rated lower than yours, so your compressor is fine. Buy a good gun and keep it for life, something that is rated well above the axle nut torque setting in order to remove them easily. I run it at 90-100 psi. hth.
#7
Banned
take the center cap off the wheels, bolt the wheel back on and put the car on the ground.. makes it a little easier to get the axle nut on/off than pushing the suspension around
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#8
yep. A solid length of pipe will work too. I basically got a 3-4' extension like billman was saying...and jumped around on it til it came off.
#10
Registered User
When the tank is filled to full pressure, your tank will provide enough air to the impact wrench for a few seconds. The compressor itself cannot keep up with the demand if you use the impact gun continuously, but if you run the compressor until it shuts off before starting to use the impact, you can probably get the nut off. If the compressor motor kicks in, quit using the impact until the compressor fills the tank and shuts off. I use an IR 231 on a compressor with a smaller tank and about the same air production; I have to wait but can get the job done for anything I've encountered.
If you remove the center cap, you can access the axle nut through the center of the wheel. With the wheel on the ground, the e-brake set, and maybe the wheels chocked, you get a solid platform to work with if you put the jack handle on the breaker. But be careful: you don't want to be injured if the breaker snaps.
If you remove the center cap, you can access the axle nut through the center of the wheel. With the wheel on the ground, the e-brake set, and maybe the wheels chocked, you get a solid platform to work with if you put the jack handle on the breaker. But be careful: you don't want to be injured if the breaker snaps.