lets talk springs

[Shade Tree Welder]

Originally Posted by LKeithR

If you duplicate the diameter of the coil, diameter of the wire, no. of turns and the length of the coil you should be pretty close. You may see some variation due to the metallurgy of the wire but it shouldn't be much and, unless the factory spring is something really special--which I highly doubt--an aftermarket spring should be fine. The trick is to get one as close to the original as possible. Any deviation from the parameters of the original will change the overall spring rate...

Also how the spring was heat treated, can significantly effect spring rate

Originally Posted by slip knot

Already had the CNH part ordered. I’ve got 2 of these early 2000 tractors and an 861 so I’m sure I’ll get a chance to try a generic spring out soon enough.

Take the new spring measure the length of the spring, then add a known weight that will compress the about 1/2 of the usable length. Measure the length compressed with the known weight. You can then calculate the spring rate.

Usable length: if you have a spring that is 3" long unloaded and 1" long completely compressed your usable length is 2". So you want to compress the spring to 2" overall length or 1" of compression.

So if it takes 10 pounds of weight (force, close enough) to compress the spring 7/8" (0.875") you can them calculate the spring weight.

SR = 10/0.875 = 11.4.

Always use a new spring to determine spring rate. Old springs maybe "soft".



So, if your system does not have an adjustment but you can use shims, go with a slightly lower spring rate and get your force higher with shims.

If you system has an adjustment usually a screw system of some type, you can go either higher or lower on the spring rate depending on how much adjustment you have either way, longer or shorter.