need some help with DIY spring arching/de-arching

[RobSelina]

I'm attempting to de-arch my rear leaf springs to lower the rear of the car.

Jollyroger talks about doing this here:

https://www.britishcarforum.com/ubbthread...true#Post152095

"You can take the spring pack apart. Lay the main leaf(long one) inverted over the anvil or vise. Take a ballpean hammer and hit the spring where it touches the anvil. as you do this slide the spring back and forth while you strike it with the hammer. This will cause the spring to flatten out or uncurl. You can also add arch by turning the spring up(you know where both ends are up rather than down. Only hit the spring where it touches the hard surface. I use a vise and close the jaws. I use the area created by the closed jaws."

Well, I've got my spring pack apart and I've been whacking on a leaf for the last 30 minutes but I'm not getting anywhere. I might have removed 1/16" of the arch (measured by placing the leaf inverted on the work bench and then measuring the 'height' of the spring.

Some specific questions:

1 - hammer - does it have to be a ball pien hammer? I've tried using a ball pien hammer and also a 5 lbs hammer (flat surface) and they both behave the same.

2 - striking surface - I have a flat spot on my vice, am I to strike at the center of the flat spot or am I striking at the edge of the flat spot where the spring contacts the vice? if in the center, how wide should the surface be?

3 - heat - is the use of a torch ok or am I just going to ruin the springs?

Any advice appreciated. I'm not getting very far on my own /ubbthreads/images/graemlins/hammer.gif

 

[regularman]

I took my springs apart when I was doing all the suspension and put more arch in them because I thought the back end was setting a little too low and kept dragging the muffler. I cut sheets of white teflon and put back between the leafs to replace the worn our stuff that was in there. Dont want any squeaks.

 

[RobSelina]

Re: need some help with DIY spring arching/de-arch

Think I've got this one figured out!

I took a look at how the pros do it and it seems they all use a break or what I call a roller-break. Not having access to one at this time of night, I set up a small stand and placed two pieces of 2" square tube about 4" apart on top of it. Striking the spring between the two square tubes seems to do the trick!

 

[aeronca65t]

Rob:

I borrowed a hydraulic tubing bender (the cheapie type that they sell in Harbor Freight). I fashioned some wood blocks from 2X4s to sit between the pipe mandrel areas and bear against the leaf. Then I just cranked the bender until it was de-arched a bit. And I didn't attempt to bend it all in one area.....I kept moving the leaf around so that the "unbending" would be spread out.Once I got a left-side leaf flattened a bit, I bent a right side leaf to match it.
I think I de-arched all but the shortest leaf (which was too short for the bender).
It was a lot of trial and error, but eventually, I got them de-arched about right. I added two extra leafs while I was at it.
By the way, I assembled the leaf packs and put them back on the car at least three times before I was happy with the ride height (so it took quite a while to do). Later, I added spacers between the axle and leaf to get the car even a bit lower.
Always bend these leafs cold....no heat.
When I was a kid, I de-arched some leaf springs by putting them in the crotch of a tree and slipping a long piece of 2" pipe over one end to bend them back.

 

[RobSelina]

Re: need some help with DIY spring arching/de-arch

Thanks Nial,

I have an HF pipe bender and I was considering using it like you mentioned but this seems to be working out just fine with the 5 lb hammer. I feel like I have quite a bit of control. As you said, I'm moving the leaf back and forth to remove arch evenly along their length. I think I have three leafs on the passenger side pretty close. I'm going to move to the drivers side shortly.

As for assembly and disassembly, already pulled the leafs 4 times trying other ideas so I'm getting used to it /ubbthreads/images/graemlins/laugh.gif

Should have her ready for a drive this weekend if all goes well /ubbthreads/images/graemlins/wink.gif

 

[RobSelina]

Re: need some help with DIY spring arching/de-arch

well, I finished my first shot at the passenger side yesterday. I think I'm going to be pretty close, at least I hope so /ubbthreads/images/graemlins/wink.gif

I've got the drivers side started and I'll finish it up this evening if all goes well. Hopefully this won't take too many more tries to get right!

 

[aeronca65t]

Re: need some help with DIY spring arching/de-arch

Sounds good....I may try the "hammer method" next time. (hope you're wearing ear plugs!)

I've pulled the left leaf spring and rear hub off mine yesterday (to fix the crash damage) so I'm working on the same area of my car (and my back is aching from it!)

 

[DrEntropy]

Re: need some help with DIY spring arching/de-arch

Awful to get "old" ain't it?!?! /ubbthreads/images/graemlins/wink.gif

 

[jlaird]

Re: need some help with DIY spring arching/de-arch

No no. Getting old means we have time for more play and hopefully the funds to play more.

 

[RobSelina]

Re: need some help with DIY spring arching/de-arch

Definitely have been wearing ear protection!

Well I finished up both spring packs today and threw them back in. Came out great! I'm about 0.75" taller on the passenger side than I was with the inverted main leaf and 1.25" taller on the drivers side. There used to be about 0.75" differential drivers side to passenger side but I've managed to get that down to 1/4" (sag towards the drivers side still).

I'm now about 1.25" taller in the rear than the front, seems about perfect and of course, I've got my spring rate back!

A few notes on how to get this pretty close the first time:

I measured the height from the rocker to the ground just infront of the rear wheels. Also did the same behind the front wheels. My initial measurements showed me I wanted to be about 2.5" lower than stock, and about 0.75" taller on the drivers side than passenger side (to level her out)

I started with the passenger side. I took the second leaf in the pack, laid it upside down on the work bench and measured the distance from the work bench to the spring bolt hole. I de-arched the spring until I had subtracted 2.5" from this number (ie - I started at 5.5" and stoped at 3").

For some reason I didn't trust myself and only made the drivers side spring about 0.5" taller than the passenger side spring, which is why it's still not level....

Anyway, I haven't torqued everything down yet so I'll have to do a little work on it tomorrow, but I'm looking forward to taking her out for a spin!