The Dodge Challenger Message Board

Is it worth it to re-arch the leaf springs, or is it better to just replace them? Any comments welcome.

I don't have any experiance with new off the shelf springs.

I have had some re-arched in the past and it worked out fine. They looked a little too high at first but then settled down after a few weeks.

Same thing when I had my existing springs made up from scratch to my own spec. Except they settled a little too low. I took them back and had a bit more arch put in and they are fine now.

Didn't someone on here get some new springs and found they were too long?

I think the best idea is to replace them. I plan to do so when it comes to my old pair of springs.
I believe that it is more likely that you will get springs that are up to specification if you buy them new. (If it is very cheap to re-arch them, I would probably give it a try....)

It is pretty cheap to get them re-arched. Maybe a third or the price of new springs??

It's also a good idear to get an extra leaf added as well.

www.espo.com for new springs

I second that. They are the best company I have dealt with for ANY suspension parts.

me 3rd. Unless you want to pull them off again just get new ones. alot of places re-arch springs by heating them up and that weakens the metal. Hydraulic bending is better but I would still get new ones.

You are wrong about that Von. Controled rate of heating and cooling is how the springs are made to start with. This has to be done by a spring manufacturer. Doing it right will make the spring like new. It is what puts the streangth into the metal. Cold bending is what weakens metal.

Indeed I am. I spoke with another guy 2 days ago and he too told me I was wrong. sorry. shows how much I know.

My leaf springs are rather sad (springs sit totally flat without any load), and the rear seems to sit too low for my liking (actually hits the bump stop with 4 passengers). I've read your comments about re-shaping the springs and have also read articles about shot-peening to provide strength etc. I also noticed in one of the posts that Hans has installed air-shocks to lift his rear end a little. As a stop-gap, would this assist my low rear end? (running 14"x7" rims all round)

Got the springs re-arched Monday. Brought the rear up 1.25 inch, then lowered the front 1 inch. Makes the car look a whole lot nicer. My shackles were almost worn through, could have lost the rear end the hard way!

Air shocks can get you by OK but for not much more hassle or money you can get the springs re-ached. I would only use the shocks if there was a good reason that I could not get the springs done.

If you don't need these air shocks for any special reason don't buy them. They suck; it gives a bad traction these things. The more you inflate them, the less traction you have. Go for the re-arching process I would suggest, it won't be more expensive I guess.

Advice noted and will be followed in regard to re-arching the springs. i checked out www.espo.com to see what they have to offer too. At US$140-160 a pair (if memory serves) they are not too expensive to replace anyway. Many after-market spring & suspension parts suppliers here are importing cheap Korean spring steel and these are absolute crap. In many cases the springs sag again within months due to the poor quality steel in them.

I've removed the leaf springs and will be taking them to the city this weekend to have them re-set (re-arched) by a professional spring makers. Removal was not as easy as I thought. The nuts securing the U-bolts were almost like they were welded on (are they designed to be undone or cut with an oxy and replaced with new ones?). Anyway, my question is: how the hell do you get the shackle rubber out of the rear section of subframe (burn it out?). Next question: how do you get the new ones in? As they're flared on both sides, it seems to me like it's going to be a not too easy task. Any suggestions from those who have done this would be appreciated.

I don't remember having any problem getting them out. I think I just hammered/poked them with a screwdriver or something.

I would never replace them with new rubber bushes. I always use polygraphite bushes. They just work so much better. Plus they are easy to fit becase they come in two halves that you just insert from each side.

Thanks for the advice Dave. I've had the springs re-set and new straps fitted too (the strap that holds the springs together in two places). They've re-set to give me 2 1/2" lift, but will sag to only 2" with time. The poly bushes they supplied are ever so slightly different in inner diameter as they're metric and for an early model Toyota Landcruiser, but seem to fit well. I'll be putting the springs back on today, god willing, and hope that the U-bolts aren't as hard to get back on as they were to remove (every turn of the ratchet handle with a helper pipe was agonisingly painful and loud and nuts were too hot to touch from friction when finally off).
The whole exercise set me back only A$160 - or about US$80

This is where a tap and die set comes in VERY handy. I did without one for years because they were so expensive but these days you can get them quite cheap. I use mine all the time now I have one and can't understand how I managed before. I run a die down just about any bolt that comes off the car that looks dirty or dry and rusty.

Any play in your spring bushes will cause sideways axle movement and you want as little of that as possible. This is why I personally don't like to use rubber bushes.

I re-fitted the springs last night (I'm about a day in front of the rest of most members) and had an easier time of it than removal. The poly bushes fitted well and there's little to no play in them. The U-bolt nuts were easier to put back on than remove and I noticed that the more turns, the hotter the nuts became and the easier they were to screw back on. Once I had a break for a smoke and when going back to the same nut, it had almost seized. I wonder if this is a design to stop the nuts ever coming loose or something? I noticed three identical 'scores' running the length of the thread on the inside of each nut. Very hard to see, but there from factory. Perhaps this is designed to dig into the thread of the U-bolts to secure them fast?
The re-set springs certainly give the whole car a more aggresive stance. Feels like a completely different car to drive (from my 5 minute drive last night dodging 'roos everywhere). I would recommend this to anyone who has a sagging arse-end.

I still have to do the wheel rotation thing again to determine the gears and will try all combination of turns to determine ratios and report back again. Yes - I plan to buy/get given a tap & die set soon. I know how handy these are and the kit is on my wish list for fathers day.

Nice one, Roger! I recently replaced the springs on my Chally with some re-arched SS type (5 1/2 leaf) springs. Not driven it yet but the car sits an easy few inches higher (better for when I fit some 275/60-15's) and is very firm when bounced. Can't wait to see if the car hooks up firmer. The old u-bolt nuts were so stiff that I ended up grinding the u-bolts off. I was putting so much force on the nuts that the u-bolts were twisting out of shape anyway! Luckily, convertible Chally owner Chris sold me a spare set of new u-bolts.

The original u-bolts do seem to be a tight fit and I suspect they were indeed made like that. The replacements I got have an ordinary thread but after a couple of years they were getting hot coming off a bit like the old ones so maybe it is just age and corrosion.

A nut does not come loose if it is tightened correctly. That is what torque settings are for. The nut has to be tight enough to make the bolt stretch slightly. This is what stops it working loose.

If the nut is a tight fit on the thread then the torque setting you get will be false. The bolt will not be stretched and even though it was tight going on it may in fact now come loose.

An older mechanic friend of mine once told me to use the FT (F* Tight) setting for tightening most bolts. I don't ever recall anything on his car coming loose.

My dad never used a torque wrench in his life. When I was a young lad helping him and wanted to know how tight a nut or bolt should be he used to say "Tight is right. Too tight is knackered." However he never built anything more complicated than an old Ford Crossflow 1300.

I have three torque wrenches of increasing size and I use them all the time on anything I consider 'critical'. If you have a load applied to a part that is bolted in place it does not 'feel' the load until it surpasses the load applied in the opposite direction by the bolt. So anything that has a load applied is in danger of failing if not at the correct torque.

So in other words if your u-bolts are not at the correct torque not only can the nut come loose but the bolt could fail (snap) under heavy stress.

As Dave has already mentioned Phil, the car will settle down a fair bit with time. This arvo, I took the family for lunch (5 of us for a 50 kms trip) and the car handles much better now with the 'new' springs. No more slowing down for dips and feels so much firmer around corners too. Upon my return home, I noticed that the springs have settled about 1/4" - 1/2" already, - what I was expecting and hoping for because it was a little too high before.
After the first hour of effort to remove only 3 of the 8 nuts securing the U-bolts and bending my helper pipe, I very nearly took to them with a grinder I can assure you. Not having replacements was the only thing stopping me.

I appreciate your comments and agree entirely Dave. Not having a torque wrench myself, I applied as much pressure when re-fitting the nuts, as it took to undo them, which was a great deal i can assure you.
After yesterday's little cruise, I will jack the car up and check all underneath to make sure everything's okay. I'd hate to have "rear wheel steering" all of a sudden

You know how one small job leads to another.....?

Swapped on the new KYB gas shox at the weekend, then realised how badly flat my leaf springs had gone when the tyres were hard up against the arches. Found a place locally that does the heat treatment re- arching process. Do I need to give them spring rates, etc, or will the process automatically return them to their original state?

The KYB's are a vast imrovement on the old air shox, if you ignore all the smoke and grinding noises.}

The spring rate is fixed by the number of leaves and the physical size of each leaf as well as the material used. That does not change.

You can measure your spring rate by first measuring your own weight and then, after removing the spring, stand on the spring in the middle and measure how far it deflects under your weight. You can then divide the measurement into your weight to get the lbs/in spring rate.

What does change over the years is the static shape of the spring. It gets flatter.

The heat process allows them to re-arch the spring to the correct shape so the car sits at the right height.

When I had my springs made to my own spec (uprated 30%) I did a whole load of complicated sums to work out what the static arch height should be. I still got it wrong and had to have it done again!

So, unless someone on here knows a sure fire way of working out how much extra bend in the spring equates to how much extra lift you get, you are going to have to just have a guess at it. Bear in mind you are better off if it looks too high at first because it will settle a little after a short period of road use.

Thanks for the advice Dave. I'll go with plenty of arching to start with, and see how they settle back. Hopefully, with improved springs, new shox and the cage, my 60ft times will come down a bit now. Fingers crossed!