'C Notch' How to Do It Yourself!
The C Notch...
Ok, so you want to lower your ride way low, but your rear axle is gonna hit your frame... No problem, we will just make a c notch in it. You can either do it yourself or buy a kit.
There are about a thousand different c notch kits on the market, and probably one to fit your ride. They are very affordable, and are easy to put on.
However, if one isn't available for your specific model, or you just want to do it yourself, congratulations! You're the kind of person we're looking for!
First you want to get your frame up where you can work on it. Jack it up, get it on GOOD jackstands, and level it side to side at the front and at the back. You can use flat pieces of metal to shim the jackstands if you need to. It's good to have a jackstand on each side of the c notch you're going to make. (Just in front and just in back). This will support the frame as you cut it and will keep it from moving...
Now then you want to grab a plumb bob (a weight on the end of a string that will show you a perfectly vertical line) and mark where the center of the axle will come in contact with the frame. If you don't have one, just tie a steel nut to the end of a string.
Ok, now that we know where we want it, you will have to scrounge up some steel pipe. You want it larger than the diameter of your axle. If you axle is about 3 inches in diameter, then get some pipe 4-5 inches in diameter and 3/16" 1/4" thick to use. This will give you room for the axle to move around.
Note: DO NOT USE: Black pipe, water pipe, or cast iron pipe! If you saw or drill it and the chips are like powder, the pipe is iron. Don't use it.
You need STEEL pipe. Go to a steel supplier and get some steel pipe. You only need about a foot, so try to get some scrap or have them cut you a foot of it...
Now cut a chunk of that pipe the same width as the frame.
Now you need to figure out just how much you want to go into the frame. If you need to go just into it a few inches or less than half the thickness of the frame, the following will show you how.
Hold the pipe up to the frame centered on the line and as high as you want the c notch to be. Now draw a line around it to show you where to cut.
If you need to go more than halfway through the frame, you need to do some more work. We will cover that at the end of this article.
Now cut that part out. Don't cut on the line, but cut just below it. You can use a torch, cutoff wheel, sawzall, plasma cutter, etc. Now finish grinding and cleaning up your cut up to the line. That way your pipe will fit nice without lots of slop.
So far we've done this:
Now hold that piece of pipe up into the cutout and mark where you need to cut the pipe so it will be flush...
Ok, now hold your chunk of pipe in the cutout nice and square and weld it in.
If your frame is a boxed frame, you're done. If it's a 'c' channel frame, you need to box it in for strength. Just cut out a cardboard pattern of the side going down the length of it about a foot either way. Now transfer it to some 3/16" or 1/4" steel, and weld it in...
What do I do if I have to notch more than half the frame?
Well, as long as it's not too severe, you can just use that other piece of pipe you cut in half...
Note: If you have to go almost through the frame, you are going to have to do a monster notch. You can see how to do that here:
The Monster Notch! How to Lay Frame...
Set the extra piece of pipe on top of the frame, and weld it on.
Now you need to box it in. Just cut some cardboard templates, transfer to your metal, and weld it in...
If your frame is already boxed, weld the piece of pipe on top, but make some templates like the ones pictured. That way everything is tied in nice and solid.
Return from C Notch to Suspension
Return from C Notch to How-To-Build-Hotrods