Thread: Bundalenes '51 Restoration

Back from Christmas stuff and helping our father-in-law move and settle into his new accommodation.



Thanks Steve for the info, you are right, who will ever know the difference between 5.6mm and 6mm for the 2 main leaves. Mine are the 9 leaf set, 7 x 5.56mm and the bottom pair, 2 x4.76mm. I could be still looking for thinner material for the front springs though.




I have had the rear springs disassembled and in a molasses bath since just before Christmas. I have now pressure washed these, cleaned them, coated them individually with Penetrol, preserving the used look. I chose not to sand blast and paint.








I then cleaned out the bolt holes with a 5/16 bit, greased each leaf with Dixon's ( a graphite mixed with linseed oil) which I have had in the cupboard for years. I will probably regret this later as the stuff is hard to wash off your hands or clothing. Then inserted the shackle bushes, which I machined down in length, earlier.

The center bolt is a 5/16 x 2 1/2 inch BSF Ubrako allen head bolt with a nylock nut and the pack clamp bolts are the same at this stage (also have heaps of these bolts in the cupboard) I made the spacers from some old County 5/16 steel fuel line I found. All bolts and bushes were installed with graphite to make removal easier in another 50 years time or so.












Rear springs are complete, with a free camber of 4 inch for the passengers side and 4 1/2 inch for the drivers side. I will make a second set when our Spring guy gets back from holidays and quietens down a bit.






That lot took heaps of time, plus the research associated with this. BTW I was reading some articles advising not to grease springs as the material breaks down. This as much as anything has been a learning exercise.

Grease and dirt makes for a good lapping paste, I was told that it would wear the leaves faster.

Originally Posted by slug_burner

Grease and dirt makes for a good lapping paste, I was told that it would wear the leaves faster.

This used to be my view on the subject, but my views have shifted. As with any subject such as this, it is a compromise. Grease and dirt do make a good lapping paste, but on the other hand, un-greased springs ride much more harshly, and in most cases rust is more of a threat than wear - and water plus dirt is just as good a lapping paste.

The ideal is to have the spring completely enclosed in a flexible, waterproof casing, fitted with a grease nipple, and grease regularly - this was what was done on many luxury cars when these had leaf springs on all corners, but the problem is getting casings that stay waterproof, and ensuring regular greasing. If the casing lets water in you have the worst possible situation - water, dirt, and it never dries.

My present position is to disassemble and grease the springs ecery few years, spreading the leaves and greasing a bit every service.

John

Before I put the parabolic springs on my series 3, every couple of months I would jack the vehicle up from the chassis to let the axles drop and the spring leaves separate as much as possible. I would then spray them liberally with Innox three or four times over a two or three day period. I buy the Innox in a four litre container and apply it with a spray bottle, but the pressure packs would do the job, just a little more expensive.
Anyway this really gets the springs freed up and moving, only down side is you get a bit of clunking as the leaves move over any of the wear lips/ridges on the next spring. Nothing a bit of time spent dismantling and dressing with an angle grinder wouldn't fix.


Cheers, Mick.

Have you thought about UHMW polyethylene plastic tape on the upper sides of each leaf (apart from the main leaf) this allows for reduced friction between the leaves but does not attract grit to act as a grinding paste.

If those Unbrako cap screws are high tensile they most probably snap with shock loading. Ever noticed that all OEM springs are fitted with mild steel centre bolts. All centre bolts are mild steel the will bend a lot before they snap.

Originally Posted by groucho

If those Unbrako cap screws are high tensile they most probably snap with shock loading. Ever noticed that all OEM springs are fitted with mild steel centre bolts. All centre bolts are mild steel the will bend a lot before they snap.

Point taken. These bolts are pretty tough, however, I have some mild steel bolts here in the drawer. It took about 10 minutes to turn down the heads and fit these. This now looks similar to a bolt I have just removed from a front 80inch front spring



replacement bolt




One I just removed






Erich

You are going well Erich.
I grease all my springs as well with a moly grease.
I bought new centrebolts from the local spring bloke, because he had them.
Turning down the heads of an ordinary bolt may be OK but often the socket that the peg head fits into can be worn especially around the entry.
The longer head gets further up the hole and can locate better.

Keith