Fixing a rear transverse spring


 
 


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Copyright ©2000-2007
by Eric Kieboom &
Jacob Poortstra
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The problem

The transverse rear leaf spring on Triumph Spitfires can be a source of endless head scratching, pub discussions and general misunderstanding. The rear of a well-travelled Spitfire may be sagging, or the front may seem to be pointing upwards. Most of this can be traced back to the rear transverse leaf spring.

The 'before' picture. Car is clearly unbalanced, too high at the front, too low at the rear.One of our Spitfires had a saggy rear end. This was not as apparent at the rear of the car as at the front: the nose was clearly pointing upwards. We could have fitted shorter front springs, which would have lowered the car overall. But that would only be tackling a symptom and not the problem itself, which was in the rear transverse leaf spring.

Measurements of Meijerink PTFE discThe solution

Contrary to what many believe, a Spitfire with a saggy rear end doesn't necessarily need a complete replacement spring. There are other solutions, among which is the 'Meijerink set', a tweak that is popular among Dutch Triumph Spitfire and GT6 owners. The original sets are supplied by Henk Meijerink of Coevorden through the Dutch Triumph Spitfire Club, but if you have access to a lathe and PTFE stock, you can easily make your own. The sets consist of eight PTFE (aka 'Teflon') discs that replace the usually perished (or completely missing) original rubber discs that sit in between the individual rear spring leaves. The results can be amazing. Ride height is restored to an acceptable level (not sky-high, as with some re-tempered springs), ride comfort improves and the new discs will never perish again. Some people have reported that the 'natural' noises coming from the rear suspension and final drive (notably knocking of the U-joints and whining of the diff) are more pronounced after fitting the Meijerink set, but we haven't noticed this ourselves.

Installation

Fitting the Meijerink set is fairly easy, even for the mechanically challenged. The required steps are as follows:

1.
Chock the front wheels (use bricks, stout pieces of wood, mother in law, anything that will prevent the car rolling), disengage the hand brake, jack up the rear end of the car, put firm axle stands under the chassis.
2.
Remove both rear wheels.
3.
Get in the car and remove the six screws and cup washers from the rear cockpit board.
4.
Remove rear cockpit board.
5.
Remove four self tapping screws from the floor hatch over the differential. Use a crosshead bit and a spanner to get at the rear ones, since the fuel tank sitting over the hatch will prevent the use of a normal screwdriver.
6.
Hatch over the diff opened, looking at the four studs holding the spring pack.Remove hatch over differential. You will now be looking at a lump of metal with four studs protruding from the top of it, with nuts on them. This is the spring pack. Unmodified, pre-MkIV Spitfires have six bolts here. They also have many more spring leaves in the pack and the whole pack is bolted rigidly to the diff.
7.
You need to remove the studs. If you're lucky, they will come out of the differential by just turning the nuts. If not, you'll have to use a counternut on top to prevent the nut turning. Screw a nut (fairly tightly) on top of the nut on the unwilling stud, then unscrew the stud using a spanner on the lower nut. The top nut (counternut) will prevent the lower nut unscrewing and the stud will have no choice but to come out.
8.
Bolt holding the upright to the spring has just been removed.Get out of the car, under the rear wheelwells and remove the bolts that secure the vertical links to the 'eyes' of the spring on either end.
9.
You may have to undo the bottom nuts of the rear shock absorbers at this point and get the dampers out of the way, but in most cases, it's not yet necessary.
10.
Extracting the spring pack.Now for the grand moment: extract the spring assembly from the most convenient side of the car. It helps to have an assistant on the other side to'guide' the spring through. At some point, you'll find that the spring needs rotating to get it out, but you'll be surprised how easy it all is.
11.
Complete spring pack removed, but not yet disassembled.There, it's out. Grimy lump of steel, isn't it?
12.
Looking at the diff from inside the car - look ma, no springs!Cover the four stud holes on top of the differential, so no rubbish can drop into the diff.
13.
Get the spring assembly onto the workbench and undo the centre bolt from the pivot box.
14.
Undo the bolts holding the four U-shaped brackets onto the spring assembly. Some of these bolts may have rusted solid (most likely the outer ones) and shear...
15.
Spring pack disassembled, some new discs already in place.Take the individual spring leaves apart. The two largest spring leaves can only be separated after bending the two brackets a bit. You may encounter some perished bits of rubber in indentations on the end of some of the leaves, but they may also have pulverised and vanished altogether.
16.
Remove any perished bits of rubber you find. and clean up the individual spring leaves a bit with a steel wire brush.
17.
the old, perished rubber discs, next to the new PTFE discs.Restack the springs using the new discs in the indentations.
18.
Compressing the spring pack in the vise.Compress the spring pack in a vise and refit all the bolts. Replace any rusty nuts and bolts with shiny new ones.
19.
The springs, complete with new PTFE discs, back in place.Put it all back in place again. Once the spring pack is back in the car, check if any of the new discs have slipped. Push them back into place with a screwdriver if necessary.
20.
The 'after' picture: car is much more balanced and level.Go out for a test drive and enjoy the rejuvenated ride of your Spitfire!

Final points

  • Work safely. Never work on a car that is only supported by a jack. When working on a car with the rear wheels lifted, always chock the front wheels.
  • Use the right tools. It makes doing a job like this so much more satisfying.
  • Rusted up bolts are never a problem, they're a challenge. And just think how satisfying it is to replace them all with shiny new ones!
  • Never re-use Nyloc nuts - always replace used Nyloc nuts with new ones.
  • Work methodically and don't rush things. Always remember it's part of the hobby. If you're fed up, just lay down your tools for a while and finish it later.
  • Be proud of your work.

If you have any comments, constructive criticism or questions, please let us know .

copyright © 2007 by Eric Kieboom