Front Springs

[gungehead]

Hi,
I am hoping to refresh my front suspension of my 3.8 mk2 with new springs and dampers,
I am thinking of Watjag firmer springs and Gaz adjustable dampers.
I understand the dampers are a straight forward job to replace.
Are the springs a difficult job to swap? Do I need a special spring compressor or will normal spring compressors do the job?

Thanks

Dave

[piman]

Hello Dave,

if by normal you mean exterior compressors then no they will not, or more accurately you will need to remove the bottom wishbone to use them, I think? Even so it will be quite tight I would imagine.
The normal spring compressor is a stout threaded rod and top and bottom parts that seat onto the top of the crossmember and the bottom spring pan. (After removing the damper). Wind it up tight, unbolt the bottom spring pan then unwind the compressor and them remove the spring out through the bottom wishbone.
You can hire the correct compressor from the club shop.

Alec

[Martec]

I totally agree with Alec, if you look at the construction of the lower front wishbone you will see what Alec is refering to.

Also the spring is halfway along the wishbone so is supporting twice the wheel weight (not an elegance explanation). These springs even standard ones are very powerful and very dangerous, I always secure the spring with rope to the car in case it gets loose.

Again I would strongly suggest you hire the correct spring compressor from JEC tools (Annie Jenkins). But you need to take a number of issues into account.

The standard spring with the lower spring plate will be about 3" to4" below the wishbone before all the tension is released, also the car needs to be high up to get the compressor rod into position.

Just replacing old standard springs with new standard springs may well not leave your car level side to side or at the correct height, so have you got some spare shims (1/8" or 1/4" thick)? So you will be refitting the springs at least twice, also all springs settle to some extent so it will need doing again!

I'm assuming the Watjag uprated springs (0.71")are the same as the ones I bought and now have in the garage loft, they have a smaller inner diameter and DON'T FIT as there is a sleeve welded into the top of the front subframe to locate the spring. I had to chisel this out (subframe still in position) but I had made some new shims 1/2" thick with a sleeve to fit the new springs. The (0.71") springs are far more powerful but shorter so more shims were needed to get the car to the correct height (both lower wishbones horizontal).

Also to help refitting I bought some 6" long bolts and used 4 as guides to refit the lower spring plate correctly.

As soon as you have fitted the uprated springs and take it on the road you will find frightening understeer as you have changed the tyre loading, so you need to reshim the top wishbone to introduce 1/2" to 1" of negative camber, then it will work.

I repeat these are very powerful springs and the job is not to be taken on lightly, the load you are putting into the central nut was at times frightening.

I have written of this many times and done the job many times but it is still the most testing job on these cars for me, I was forced into this job for our comfort but wouldn't do it unless I had to.

I have not written this to frighten you, but to make you aware of what you are taking on, I would much prefer to take an engine out several time than springs several times.

Set up correctly then these springs with negative camber and a thicker ARB make the car handle very well with much less roll. Spirited driving will allow limited power oversteer..............more fun.

Brian

[gungehead]

Hi Alec, Brian,
Thanks for the information.
It sounds like a job for the mechanic. I have handled springs before on several cars but all much lighter cars than a mk2. But as you seem to need plenty of room underneath the car to get the spring and compressor out, I think I will trust the job to the mechanic. The camber and tracking will need to be adjusted once the new springs are in, which is a job I cannot do and the mechanic has the tools for that job so he can do it all.
The only question now is do I get him to change the rubber bushes for poly whilst the spring is out? He does not seem to be a fan of polyurethane!

Thanks
Dave

[ManxNeil]

I endorse what Brian has said. I was fortunate in that my subframe was on the workbench when I changed the springs but it was still a nerve-racking job, knowing the power of the springs and how much tension they were under - far more so than when I fitted new coils to the front of a Triumph Vitesse a few years before. Brian's tip about longer bolts to position the bottom pan is also a very good one.

With regard to bushes, I fitted Polybush items throughout (including the anti-roll bar) and have been very happy with them. Though a 'before and after' comparison would have been meaningless on my car as it was in generally poor condition beforehand, I since drove another well-sorted Mk2 on fairly new rubber bushes and formed the impression that my car was 'tighter' in terms of handling. Hopefully they'll last longer, too.

Cheers,

[piman]

Hello Dave,

it's your car, so your choice and during a spring change is a sensible time to do it. The spring needs to be removed if you want to change the bushes so why do the job twice?

I will change my bushes when I come to it with Superflex polyurethane ones.

Alec

[gungehead]

I have spoken to Ken Jenkins regarding the springs he developed and are sold by Watjag. I was a little surprised by the poundage. Standard are around 400lb/in Watjag uprated just under 700lb/in.

I am used to MG Midget springs - a much lighter car and softer springs to match - uprated to 320lb/in. But when you consider the Jag is twice the weight of the Midget, the spring rates are comparable.

Dave