Adjustable lumbar support retrofit...sort of

[Lazlo Woodbine]

I find the lumbar support in my S-type Sport seats a bit lacking. I knew that electrically adjustable support was an option so this week when I was taking bits off an SE spec scrapper that had it I investigated.

I assumed it would be a pneumatic system but it's actually a bit cruder than that; It's a diaphragm of spring steel flexed by a little electric motor with a bowden cable to actuate it. I realised that the motor had been fitted early in the assembly process so would not be easy to remove and refit. I also didn't know if my car had the wiring and it definitely didn't have the switch, which was the wrong colour anyway. So I improvised and I have to say for the time it took me it has been one of the best things I've done to the car.

What you'll need:

• The diaphragm from a seat that has adjustable lumbar support OR you could modify the standard one with a bit of bicycle cable and ingenuity.
• Pair of decent pliers
• Electrical "choc block" connector or similar
• Screwdriver to tighten the choc block

First thing is to take the back of the seat off. It simply clips in with a couple of those fir tree jobbies. I was a bit ham fisted with the scrap car and didn't break anything. I treated mine with kid gloves and pulled one of the clips off..

Doh!

 

 

This is the diaphragm in place although I've actually unclipped this one. It will be obvious how it attaches but don't struggle with it, if you do then you're doing it wrong. Just flex the diaphragm the way the spring does but go further.

 

This is the standard one:

And this is the adjustable one which is identical save for the spring and cable::

As you can see I cut through the outer and inner of the cable right close to the motor. I then pulled the inner out and cut the outer about an inch shorter, threaded the inner back through and used the choc block to set the tension.

You could be swanky and put a ferrule on the end of the outer but it's wound like a bicycle brake outer rather than multi-strand like a gear outer so it's not vital.

It's worth pulling the cable fairly tight to begin with and then driving around with the back of the seat off and the pliers and screwdriver handy to adjust it. Once it's set that's it, put the seat back back on. Obviously if different people drive the car it may not suit all of them and you'll have to compromise, but then they already have to compromise what with having no adjustment at all.

Adapting a standard non-adjustable diaphragm would not be a simple as using an adjustable one but I'm sure it could be done. Personally I would shorten the spring and heat it up to make a new hook in it a couple on inches further down to attach a cable to. Be very careful bending springs like this, they are brittle and will most likely snap before bending if not hot enough.

This how the cable attaches:

The standard diaphragm with the spring has just the same attachment point. A BMX type brake cable has a fairly large end which would probably be usable for this.

Whether you buy an adjustable diaphragm or just its spring/cable assembly from a breakers or adapt your own this is a totally worthwhile mod that took me less than half an hour all in. I'm now much more comfortable and unable to slouch in my seat even if I wanted to.

[Lazlo Woodbine]

19 minutes ago, Lazlo Woodbine said:

...when I was taking bits off an SE spec scrapper...

 

This has to be the glamorous end of Jaguar ownership no?

[Lazlo Woodbine]

Thank you. It's a dead easy job with a good pay off, that makes a nice change.

I've been using the phone as a camera for this sort of thing lately as I was getting the DSLR all oily. It shows most things ok but up close focus and bright light is a bit shaky. I have an ancient Canon point and shoot which I'll get up and running for these car jobs just as soon as I find a spare CF card.

[JOE-DOT-COM]

Hi

I'm sure mine on my 2004 S-type R are air inflating bladders

as you can hear them deflating when you retract them, they feel like a double bladder

cheers

Joe

 

[Lazlo Woodbine]

Thank you Joe, yes I should have stated that these are both X200s.

I could have done with a double bladder what with all that scrumpy last night..

To anyone considering this; It would be wise to take the cover off the back of the seat and check if it looks like the photos above before buying parts.

 

Ron: Yes I like Canons. My DSLR is a 400d and I love messing about with different lenses and filters, long exposure etc. The point and shoot is a Powershot A10 which is a mere 1.3mp but the quality of the pictures is much better than any of the phones I've had, some of which went up to 5mp or so, allegedly. That said Mrs Woodbine has a smart phone of some sort and I am quite impressed by the images that come out of it.

I actually made a macro lens, of sorts, for my 400d out of an old 35mm lens. I removed the front most element so focussing is purely a matter of moving the camera back and forth and the depth of field is non-existent even a f32. So it's not very user friendly, pretty washed out and a bit blurry. But for under a tenner it's good fun.

These aren't cropped:

Rockin' mad bokeh yo!  Etc.

[Suppedraken]

You sure know your cameras, Laz.

[Lazlo Woodbine]

Well thank you, but I'm not so sure I do. I just like to play about and have a bit of fun with these sort of things.

 

I took the back off the seat again to readjust the lumbar. It hadn't slipped, I just wanted to see if I could make it better. I'm still really pleased with the results of such a quick and easy job.