Lessons from changing front springs

[Waynebaby]

Hi All,

 

It never fails to amaze me how sometimes the simplest of tasks can throw up all kinds of pitfalls which are patently obvious after the event. I've learned a few wrinkles about changing the front springs and top suspension bushes on my Mk3 GT6 over the last couple of days which I thought I should share to avoid someone else "buying the tee-shirt"

 

This first thing I did right was to buy a spring compressor from the club shop. This made compressing the springs a (safe) doddle, which given I would end up compressing and un-compressing the springs ~ half a dozen times before I'd finished was a good thing.

 

First learning point:

 

The bottom of the damper cannot be rotated relative to the rest of the assembly once the spring is back under tension. Why does this matter? Because if you don't get the alignment of the damper lower fixing eye correct during the re-assembly of the damper/spring, you'll find that you can fix either the top or the bottom of the assembly to the car, but not both. It is important therefore when you're attaching the spring to make sure that the plane of the damper eye that the fixing bolt passes through is in line with one of the sides of the equilateral triangle that the studs on the spring retainer plate make.

 

Second learning point:

 

The top bush on the damper deforms a lot when under relatively small pressure from the retaining nut. Before releasing the tension from the spring compressor you have to attach a nut and a lock nut to the top of the damper rod. This bears onto the top of the bush which in turn bears down on the spring retainer cap thus holding the spring/damper together under tension. Do not be tempted to tighten the nut down too far at this stage because if you do the top bush deforms to the extent that its diameter becomes too great to fit through the hole in the suspension sub-frame. Before you fit the damper to the car make sure that you only tighten the lower nut down enough to allow the lock nut to be fitted above it. I've attached a photo of the correct arrangement.

 

Third learning point:

 

If you make the top bush too big as described, do not assume that tightening the spring retainer cap nuts with brute force will somehow make the bush "pop" through the hole. All that happens is you snap a stud off the spring retainer cap!

 

I don't know if that qualifies me for one Tee-shirt or three but I hope it makes sense and is of help to someone else doing this job for the first time.

 

Wayne

[dougbgt6]

Nicely done Wayne! One of the studs on my retaining cap became un-welded. A hell of a job to get it off, and new retaining caps all round,

[Pete Lewis]

Thats going to be usefull to many

 

whats next

 

Pete

[Bordfunker]

Stupid question, I'm full of them.

 

Do you need a spring compressor to simply remove the spring and damper assembly without splitting them?

 

I'm part way through cleaning up my front suspension, and was considering cleaning up the wish bones and returning them, hence the question.

 

Karl

[Waynebaby]

Hi Karl,

 

You don't need a spring compressor to just remove the spring/damper assembly from the lower wishbone and top mount. Remove the three spring retainer cap nuts at the top, the lower damper mount bolt at the bottom and slacken the trunnion bolt a few turns and the assembly will come out with a bit of leverage with a screwdriver between the trunnion and the damper. The thing to remember is not to loosen the two nuts at the top of the damper rod or else the spring will come off with a bang and a lot of released energy. When you come to put it back you will need to load the car wire 300lbs (two big mates) before tightening the bushes up to get the static height of the suspension correct.

 

Wayne