Bent leaf spring...

[irbob]

Lets say one of your leafs were bent and you wanted to straighten it out. What kind of heating and cooling, if any would be the best way to do it or would you just put it in a bender and fix it that way without heat.

Curious minds need to know...

Lets also say that this could be the main leaf right near the bushing.

[turtle jim]

I wouldn't heat it.I'd probably first lay it across 2 solid supports and hit it with a hammer.Move it a little bit each time you hit it.Will take a lot of hits to notice any change.Hydraulic press used carefully will work.
I have "re-arched" springs with a hammer.

[scotty]

i had a bent leaf spring,and it eventually broke where the the bend was. i think you will have to completely and totally elminate the crease,or bend,if not it will break sooner or later. best bet methinks is to replace the bent leaf(s)

[jeepguzzi]

The heating and cooling is pretty specific on springs. I believe that if you have a bent one, you can't really fix it without heating it. The molecules in the metal "line up" to retain the bend. That means to bend it back without heating, using hammering, you won't quite bend it at the same place. You might also be work hardening it with the hammer blows, which would make the steel more brittle and that's when it breaks.

After springs are made, they are heat treated (tempered) which is what allows them to bend and return to their arched shape. You can't really do that with a torch very well, and I wouldn't want to ride on the "fixed" spring if you did.

I'm not a metalurgist, but I have worked with steel for many years.

[dnixon]

I think if you have no other options then to heat it, try to keep it as cool as possible while still being able to do somthing with it and the rate of cool down plays a huge factor with steel. SO if you can some how slow the cooling process down your steel won't be AS brittle.. when you heat it up the carbon molecules in the steel move around and get "out of position" the faster you cool it the less of a chance that the carbon can get back into position... The more disorder in the steel the stronger it is but it's also more brittle... However it will never be the same and will always be a weak spot... Cooled too fast and its hard and brittle; cooled to slow and its very malleable and easy to bend, again... This is all based on untreated steel so results may very with the amount of tempering done from factory.... good luck... I would start looking for new spring...

[ October 11, 2002, 06:06 PM: Message edited by: Mr. Toad's Wild Ride A.K.A dnixon ]

[andy d]

you can use plain old motor oil to anneal hot steel. it doesnt cool down as fast as water

[Tad]

Bob, when I had my front springs rearched the main springs were heated in a forge and then run through a roller setup to straighten the side to side warpage. Not sure how they deal with a large part like that but in the welding shop we bury them in sand after parts are heated to allow them to cool slowly and equally, we pull the parts out the next day. Sorry, don't have a forge that big.

I used Neil at Southwest Springs, midtown, near Ft. Lowell & Alveron, 520-323-3680

[irbob]

Kewl guys or is it HOT...I don't know what I'm going to do with it yet. I think there is some kind of a spring outfit business here somewhere. I may task them to fix it. Depends on how it actually looks after I remove it. Never the less I will need to remove the bushing b4 working on it and I know those are not fun. The future will tell.

[Heimeken]

Bob, if it's the main leaf and the others are fine I would take it down to the spring shop and just have that one leaf replaced, should be pretty cheap. Taking the bushing out of stock springs can be a big pain,not fun, best thing to do is to heat them up first. Of course you'll need new ones. Cool thing about after market springs is the bushings are usually poly.

later

[will e]

I just ordered a 4" rusty lift for my 81 wag. It has 130K miles on it but if you need any of the stock springs they are yours for free. I live in Mesa and figure I will get the new lift on in about a month. Let me know.....

[irbob]

Heimeken...good to here from you. I'm going to end up doing something even if it's wrong. It is the main leaf on the right rear near the front bushing. It had to hit really hard on that side to do that kind of bend. The right side hangs down about 3" lower. Turned my 6" lift into a 3" lift. Hey what if I put a 6" block on that side to even it out. <NOT> :D Later bud.

will e...sounds good and thanks for the offer but the problem would be that this is a Rusty's 6" lift spring that is bent. You don't have one of those laying around anywhere by any chance do yea? ;)

[will e]

No Rusty 6" springs laying around.... Sorry I couldn't help.

[irbob]

Thought I would bring this back up to see if any of the new folks had some input here. I still havn' t touched it yet but the time is getting closer. TIA

[kyjman]

Springs are made of Spring steel. That allows them to return to they're original position. It like it has a memory. If you heat it or bang it with a big hammer you will totally ruin it. My advise is to go to a spring shop and have it replaced. I've worked with steel all my life(53 now) and I would never even consider heating any kind of spring steel to shape it. It not going to work. Its the same type of steel that is in frames and you never heat the frame else when it flexes it dont know where to return to and you have a bent frame.

[krob725]

bob
i think you should send the spring back to rusty to be repaired or take it to a spring shop to be re-arched. the metal it is made from is "spring" steel. it is different than regular steel. if you try to bend it back or heat it, it will either crack or lose it's tension and go flat.
good luck
krob725