Cutting a coil spring

[rocketman]

Does anybody know when cutting a coil spring,is 1/2 coils equal 1/2 inch,and so on,is there a method to figuiring it out.thanks

[Musclecar]

I cut off half of a coil and it dropped it about 1 inch. Keep in mind this was a big block coil spring.

[chicane]

There is no set measure for cutting a spring.

There is only one guideline... cut as little as needed. You can always remove more, but you can never put it back.

Knowing that a spring will 'settle'... its a good idea to cut about three quarters to an inch longer from your desired ride height. That way you can compensate for the 'settling' and not go too low.

I normally dont cut more than one quarter of an coil at a time when trimming for ride height. On my 6041's that were in my 67, I did an initial cut of two and a quarter... drove it around for 30 days to let them settle and then made my final trim cuts. The first quarter dropped about a half inch, the second about a half inch and the third dropped about an inch and a quarter. So... it goes to show that there is no set drop when cutting specific amounts.

But from a known freelength or a known 'new' spring... you can sometimes make a gross cut to get to your desired freelength a little quicker. For example, a MOOG 6041 right out of the box can take an initial cut of two and a quarter coils off to get it in the ball park for further ride height trimming.

The only other thing that needs some peticular attention, is how you cut the spring itself. Basically, hot and fast... and not to allow the material to heat soak. A perfered method is to get a five gallon bucket, put the spring into it and fill it with sand. The sand will soak up excess heat and it also holds the spring steady for you while you cut. And... MOST IMPORTANTLY... let it air cool.

[rocketman]

I didn't think you wanted to actually use a torch,I was going to use cut off or band saw to do it,is this right,never cut a coil before

[Slow Ride]

I just cut some down over the weekend. I used a cutoff wheel in my angle grinder. I cut 1.5 coils out and will probably go another 1/2 coil after I see how it sits with all of the sheetmetal and do a little driving. For my car 1.5 coils was good for 3.5" of drop

[chicane]

Originally Posted by rocketman

I didn't think you wanted to actually use a torch,I was going to use cut off or band saw to do it,is this right,never cut a coil before

A torch, if used correctly is the best way to go about it. Grinders, chop saws or sawzall will transfer too much heat into the spring itself... and that is what you are trying to stay away from all together... as that is what causes spring failures.

There are however, many ways to accomplish cutting a coil spring... and this, to my knowledge and understanding is the 'more' correct way to do it. I learned this from the old school cats wilst under their tutelage... aka Mr Guldstrand and Mr Moody. They have been cutting open coil springs like this for 50+ years with excellent results... and since learning this, so have I.

Like I said, a torch... if used correctly... is the way to go. You just gotta know how to cut "hot and fast" to minimize heat transfer/saturation into the material.

[pdq67]

I wrapped my springs w/ a damp wash rag when I cut them w/ my cheap 4.5" HFT angle grinder fine!! Steam is 212 degrees so go from there about affecting heat treat, imho..

Just keep the old rag good and wet is all.......

Chicane, did you ever check out that proto-type 2-speed '69 Mercury Cougar Eliminator rearend over on Team Camaro?? I want to say Dennis said no problem for you to check it out..

http://www.camaros.net/forums/showth...-speed+rearend

I have money I would invest in to make it to sell!!

pdq67

[Serpa69]

I cut 2 coils off of mine and this is hhow it sits