Thread: Renovating Leaf Springs

There has been a bits and pieces written in many posts. I am covering what we are doing in a Series 1 restoration. On the Series 1 there is good technical information on the spring design in the Factory Workshop Manual.


Bundalenes '51 Restoration


Pages 8 to 13 of this post.

What information are you after.

Basically measure, disassemble, molasses bath for a week, pressure clean, dry, light clean with a wire brush, paint with Penetrol, dry for 24hrs, grease with graphite if appropriate for that vehicle and re-assemble. Insert new bushes with lubricant job DONE


Erich

OK!


I plan to pull them apart- easy as they're held together by a u-shaped clamp & a bolt rather than a tang that may need oxy-acetylene heat to bend.


Then wire brush/stripper pad to de-rust.


Then paint? What's the best? Or is it not worth it as friction will rub it off?


I remember the debate raged over whether to lubricate or not. Is dusting with graphite powder between the leaves the go? Didn't some older upmarket British cars actually use grease & leather gaiters??


Then new bushes = job done.

Originally Posted by geodon

OK!


I plan to pull them apart- easy as they're held together by a u-shaped clamp & a bolt rather than a tang that may need oxy-acetylene heat to bend.


Then wire brush/stripper pad to de-rust.


Then paint? What's the best? Or is it not worth it as friction will rub it off?


I remember the debate raged over whether to lubricate or not. Is dusting with graphite powder between the leaves the go? Didn't some older upmarket British cars actually use grease & leather gaiters??


Then new bushes = job done.

Paint - I would paint the leaves even though it will rub off parts of them - the bits that do not rub will be protected. Use whatever you would use on the chassis.

Unless the car is going to see a lot of use on dusty roads, I would lubricate them when assembling with either graphite grease or MoS2 grease. This will tend to repel water that graphite will not.

Many luxury cars from all countries (in the days when luxury cars used leaf springs) used leather gaiters filled with grease. This is a high maintenance solution, and the leather is very likely to crack in the Australian climate. Once water and mud gets in, they are worse than useless.

An alternative is to interleave with something to reduce friction. Traditionally this was thin sheets of zinc, or occasionally other metals. Today teflon sheets would be used instead, and I have seen them sold in widths to suit springs. Either of these will also tend to be high maintenance as the interleaves will wear fairly rapidly and need replacing. If there are a lot of leaves, the extra thickness may require longer centrebolt and U-bolts.

John

Originally Posted by JDNSW

An alternative is to interleave with something to reduce friction.
John

The friction is part of the shock absorbing system. Less friction in the springs means stiffer shock absorbers. After replacing my original springs on my 88" SIIa with parabolic springs it was very noticable. Resolved to military 109 shocks up front and disco rear shocks for the rears.
Reducing friction does improve the ride though.

Originally Posted by AV8R

The friction is part of the shock absorbing system. Less friction in the springs means stiffer shock absorbers. After replacing my original springs on my 88" SIIa with parabolic springs it was very noticable. Resolved to military 109 shocks up front and disco rear shocks for the rears.
Reducing friction does improve the ride though.

Less friction compared to what is the question. Remember that the original suspension design envisaged smooth, non-rusty suspension leaves. Damping levels for any suspension are always a compromise anyway.

But the reduction in friction from lubricating springs is nowhere near as great as that for parabolics, where there is virtually no frictional damping.

John

True. The few leaves on the parabolics hardly touch each other.

Originally Posted by AV8R

True. The few leaves on the parabolics hardly touch each other.

Usually only at the tip of the leaves, with a nylon or other non-friction pad.

John

But they are comfy ! With the proper dampers of course.