Refurbishing old leaf springs

[dra890]

This weekend I stripped and refurbished my front leaf springs and I thought I'd write a little guide to show how I did it.

First of all you need to remove the springs from the vehicle. Actually, I removed one, refurbished it and refit it before doing the same at the other side. It is also a good idea to replace the bushes at the same time if they are anything less than impeccable. Here is one of the springs once removed. You can see how the leaves have been blown apart somewhat by rust and dirt.

Before stripping the spring apart I wanted to make sure I could get it back on the vehicle okay, so I checked that my new locating dowels would fit in the axle okay. I got them from Craddocks, although they came without nuts, and cut the slots in them myself with a grinder to help with tightening them up. Here it is compared with the old one still in the spring.

First, the spring clamps need opening up. I used a cold chisel as a wedge to open them. Once you can get a corner of the chisel over the side of the spring you can just use it as a lever to prise them open. Only open them as far as you need to.

Next clamp the leaves together (I used a g-clamp, but a vice should also be fine) and cut the nut off the locating dowel, being careful not to cut into the bottom spring leaf itself. There's no point trying to undo it - it'll be rusted solid and you're going to replace it anyway.

Then using a punch (or whatever's available) drive the dowel out of the spring pack.

You can now take the spring apart.

Give all the leaves a quick wire brush to remove the loose dirt and rust, then using a flap disc in a grinder go over both sides of all the leaves to remove as much rust and dirt as is reasonably possible. Try not to let the leaves get too hot or they could start to lose their temper. If you can touch it with your hand then you're fine.Wipe clean with a rag when you're done.

Here is my spring pack after cleaning up.

At this point you may just want to reassemble the spring and fit it, but now is a good time to do something about the friction between the leaves. There are a few options available. You could give each leaf a good coating of grease (the manual suggests carbon grease) to help the leaves slide past each other and this is said to work well, but eventually the grease will disappear, and this also tends to hold onto dirt and grit. Some people attach PTFE tape to the upper side of each leaf (except the top one) and this is also said to work well. I decided to paint my leaves with a dry lubricant to avoid attracting dirt. PTFE and teflon based paints are available but I chose one based on molybdenum disulphide. This bonds well with steel, is water repellant and is designed for high pressure steel on steel sliding components. One 400ml can of dry moly spray is enough to give a front spring a liberal coating.

Paint both sides of each leaf and allow to dry. Use plenty - I went over each side a few times to make sure I hadn't missed anywhere. I also painted the parts that wouldn't see any friction to help keep water out and prevent more rusting.

Once this is done you can reassemble the spring using the new dowel. I used a g-clamp to hold most of the leaves together while I put the last three on sideways, then once I had the nut on the dowel I strightened them up before tightening. You could choose not to use all the leaves. Leaving the bottom two off a standard spring is said to give a similar spring rate to a lightweight spring, or you could leave just one off to go somewhere in between. I assembled mine as standard. Here it is ready to go on.

Dan

[Gremlin]

Well done good write up, i usually smeer the leafs in grease, they tend to dry up but some coating in gearoil every so often works wonders. I also re arch them while i am at it with a jig and hydraulic jack.

G

[ejparrott]

Thats a fantastic job, full marks sir!

[SeriesEwan]

thats a great write up, I never thought about refurbing old springs, what's the ride like now its been done?

how do you go about replacing the wrap around clips?

[Gazzar]

Like it - a couple of tips:

Grind the mushroom of that chisel! Bits of that will fly off and whack something important, like freshly sprayed panels. Or it could hit you in the eye.

The clips can break when bending them - apply heat to soften them slightly and the risk is much reduced.

G.

[secondjeremy]

I think its only necessary to loosen some of the clips - and the leaves can be slid out lengthways. I seem to remember doing a set this way - but they may have had bolt-type clamps as well.

[M&S]

Need to do this with teh fire engine soon, so thanks for the write up. Not such a big job when you see it done. I shall give minbe a coating of rust concertor and then loads of grease between the leaves, then waxoyl all over them! Still bet they rust though

[Snagger]

Seeing the way the leaves were bowed and splayed in the first pictures, I thought you were on a fool's errand trying to refurbish those springs, but I was clearly wrong. It's a very instructive post - not so much the "how" but more the illustration of what can be achieved with what would appear to have been irretrievably aged springs. I'll be needing to do the same on Helena's Lightweight rear springs - they look pretty new but one is sagging more than the other (it might be poor quality steel and thus irreparable) and there is often a loud crack when pulling away; I think one of them has partially seized and a rebuild would be much cheaper and effective than replacing with another pair which would likely seize quickly too.

[SeriesEwan]

just started the same project & i also got the Dowells from cradocks sans nuts for the end

what thread are the nuts?

Many thanks

[SeriesEwan]

Finally got the nuts for them, one more question though.... do the springs have a direction? things dont seem to want to line up exactly right now & i wonder if its on back to front

[dra890]

Finally got the nuts for them, one more question though.... do the springs have a direction? things dont seem to want to line up exactly right now & i wonder if its on back to front

No, the springs don't have a direction. But yes it can be a real pain to get everything to line up properly. I found that ratchet straps come in handy.

Dan

[kevanf1]

Nice job and excellent write up. May I enquire? What sort of difference has it made to ride quality? Could you also tell me where you got your Ambersil lubricant from? I used to be able to get hold of this stuff when I worked in the automotive industry but no longer

[kevanf1]

Sorry ignore my question about Ambersil. Silly me should have used his fingers (and brain) and looked it up on Google.... where I have found loads of stockists. I'd be interested in hearing about ride quality now though

[SeriesEwan]

I have recently done this job too. Ride quality was notably improved, but not as good as new springs ( i have refurbed my back ones & replaced the front ) I Didn't use Ambersil I used grease between the leaves.

to put in perspective i can now go over speed bumps a good 10 mph faster than i could before & my spare wheel hasnt escaped once since its been done. Offroad its like a different car now too

Further to note ( and quite obvious ) removing the rust with any form of power tool makes a BIG mess, I sacrificed an old vaccum cleaner & gaffer taped it to my angle grinder & that helped a lot, Definalty wear a mask. Also I found a wire wheel much better at removing rust ( cloggs less ) and It didnt heat the springs as much.

Finally make sure you have the correct Dowell & bolt.... A certain supplier managed to get just about everything wrong twice over When I ordered these parts ( by the correct desired part number )

[kevanf1]

Mine's a 2a ambulance and my god I know about it if I even look at a speed bump It certainly does my arthritis no good at all so anything that will help is good. I'm currently in the process of doing an off road restoration on the vehicle. Part of this will be refurbishing the springs all round. I've considered fitting parabolics but the price does tend to pull me up short.... Once it's time to do the springs I'll keep my fingers crossed that they give a better ride afterwards. I am trying to both lighten and or shift centres of gravity to a lower level where I can so I may experiment with removing a single leaf all round.

[tacr2man]

Its ok to use oil or grease if you are going to fully wrap the springs, otherwise you will add greatly to the wear as dirt/grit will stick to the oil/grease and act as a grinding medium . Whats been done above will extend usable life a small amount just as having them "reset" will but you are only putting off biting the bullet and fitting new .

[Judd]

Going to have to do this to if I go over a speed bump at 10 mph it like hitting a curb at 70mph not good on the old back and head lol

But before I do a spring refurb I would like to give my truck a bit more height is there a lift kit available for these types of suspension or what can I do to give me better ground clearance

[SeriesEwan]

New springs will lift it up a bit, refurbing wont raise the hight at all but it will make your existing springs more flexible Longer Shackles might raise it a bit but that may well do evil things to your suspension geometry

[Bowie69]

Going to have to do this to if I go over a speed bump at 10 mph it like hitting a curb at 70mph not good on the old back and head lol

But before I do a spring refurb I would like to give my truck a bit more height is there a lift kit available for these types of suspension or what can I do to give me better ground clearance

Better ground clearance would be created by running larger tyre more effectively than a suspension lift...

[Snagger]

Better ground clearance would be created by running larger tyre more effectively than a suspension lift...

Absolutely right. Just avoid going too big and particularly too wide. For example, 7.50s are better than 235/85s, even though their diameters are similar. Heavily cambered springs tend to be stiffer on initial compression and have odd spring rates (because the forces act more along the length of the spring leafs rather than perpendicular to them) and suffer more bump steer as straightening the spring increases the longitudinal distance between the front end of the spring and the axle more than with a fairly straight spring. 1-ton or military shackles upset UJ geometry, causing transmission damage and also screw up steering castor angles, affecting steering feel (though this would make self centring stronger, rather than weaker).

[Normbourne]

Hi guys,

I remember in the UK we used to bandage the springs to keep the salt and road grit out of them. In oz we have a tape called "Denso" which is used by plumbers to wrap underground Steel pipes, indeed I've used it to wrap underground electrical conduits. It is my intention to wrap the springs on my vehicle with it, whilst we don't have the salt problem here we certainly do have the grit and water, unless of course we venture on to the beach or the salt lakes of the hinterland. It is a dreadful stuff to work with, cleaning your hands after use, is difficult, so the go is wear gloves. It sticks like the proverbial .... .. a blanket. Because of its sticky nature, it may be necessary to over wrap witha canvas tape, but we will see.

Norm.

[Snagger]

A lot of calssic car guys in the UK use Denso tape - it's been done since the 60s and apparently works well for road cars with leaf springs. It could be problematic for those which wade or go in deep mud, though, as it will holed water in and prevent cleaning and further lubrication.