www.jec.org.uk

Hi there!

Can anyone advise on whether and, if so how, the driver's seat can be moved further back in addition to the usual adjustment? Another couple of inches would make the driving position less confined!

regards

Brian

Hi Brian welcome,
It's a long time since I removed the drivers seat when I repaired the A/C blowers but I seem to remember that there were different bolt holes to give some additional movement fore or aft. I have the sportspack seats so they may be different to yours. Have a close look at the runners, its only four allen bolts that hold the seat in place.
Remember also that the steering wheel has some movement in it which may help.
Pop

Hello Brian,
Can you please tell us the model and year of your car. The design of the seats changed several times over the life of the car.

I recently modified the runners on the sportspack seats in my 1989 car to give me an extra 1 1/2 inches of rearward travel. But my modification is not required on early cars and probably not applicable to facelifted ones.
I'll post details if they are of use to you.
Regards,
Glenn.

Ahh, the advantages of being a shortarse! Being able to ignore 'mind your head' signs with blatant disregard, and being able comfortably fit in an XJS!

Still not worth it though!

Thanks Guys!

Option 1
I have seen the 4 allen screws but the base upon which the seat is mounted appears to be the same length, ie if the frame was maoved further back, it would 'overhang' the base. \\presumebaly then this would be ok?

Option 2
The car itself is a 1991 convertible - Feb. (non facelift) V12.

Option 3
At 5' 11" shortening my legs is not an option! Anyway there's acres of unused space behind the seat!

Thaks

Brian

Hi Brian,

I'm 6' 4" and bought my V12 XJS "hoping I could get comfortable". The seats do have two fixing positions. They leave the factory in the shorter of the two. I found a big difference by repositioning the seat on the runners on the seat and adjusting the steering wheel position further out.

Mines a 1982 model. If your set-up is the same then note; 4 fixings to remove the seat, these are allen key set screws, and 4 fixings on the runners to reposition, I think these were posidrive set screws. When you put the seat back locate the rear fastener nearest the transmission tunnel first with the seat forward on the runners (the manaul explains this is because it is the locating screw) otherwise it will be very difficult to get in and watch you don't loose the nuts somewhere in the floor section (they are not captive nuts in the floor).

Hi Brian,

I think your '91 seats will be the same as mine. Sadly, you won't have the extra sets of holes that David mentions on his '82 car. Jaguar changed the design in the mid 80's.

My modification removes the rear 'end stops' that are formed in the rails that attach to the seat base (not the ones on the end of the rails that bolt to the car floor, you still need those). This allows the seat to move back until it is stopped by the seat belt buckle fouling the transmission tunnell. It gives as much extra travel as you are ever likely to get. It is enough for my 6 foot frame so you should be OK. I will try to put some more detailed guidance on here at the weekend when I have more time.

Kind regards,
Glenn.

Thanks guys!

I look forward to hearing more at the weekend.

Brian

... and watch you don't loose the nuts somewhere in the floor section...

Well I suppose at least that's better than banging them on the steering wheel

Well I suppose at least that's better than banging them on the steering wheel

Happliy, this doesn't affect those of us with longer legs. We keep our nuts well away from the steering wheel

Ahem, at the risk of raising the tone slightly I'll try to describe the seat rail modification I made. It is only now that I wish I had taken some photos at the time, but I'll do my best clearly to describe what I did.

Firstly, remove the four Torx bolts holding the lower seat rails to the floor of the car. These use a T40 Torx bit. As cya wrote, the rear bolts are held by captive nuts in the mounts on the floor, but the front ones are held by two floating plates about an inch long. They won't drop down to a point where they get lost, but I found it easier to remove them by putting a screwdriver (or better still a lolly stick) under them before removing the bolts. They are accessible from the driver's footwell.
Now lift the seat from the car and place it upside down over a bench or table, protecting the seat facings with a cloth. It needs a firm support as you will be doing some quite heavy hammering...
You should find a metal spacer on top of each of the four holes in the floor supports. Keep them somewhere safe...

You will see that each rail is formed of two parts, one part is fixed to the seat, the other is now free to slide over the first part once you release the locking mechanism. The two parts are held apart by a number of ball bearings running in channels along each side of the rail.

If you slide the rail towards the rear of the seat, you will see two lumps on the rearward end, on the lower side (as seen with the seat upside down - i.e. the side facing the seat). These are the lower end stops. If you watch these as you slide the rail towards the front of the seat, you will see they will eventually strike two upper endstops that have been formed in the rail that is fixed to the seat base. These endstops consist of two 'flaps' of metal that have been pressed from the rail itself. They are about 4 inches from the rear of the seat. It is possible to see them quite clearly by moving the sliding rail until some conveniently placed holes line up with them.
Here somes the destructive bit
Using a mallet and a couple of different sized screwdrivers as cold chisels, you need to flatten the upper endstops so that the no longer catch the lower endstops. I found I needed one screwdriver with a 1/4" blade and one a little larger at about 3/8" to be able to get them completely flat as access to them is restricted by the sliding rails.

Do not be tempted to take the easy option of grinding off the lower end stops. I was about to do this until I realised that they also retain the ball bearings in the channels. You don't want your balls falling out when you adjust the seat do you (sorry lowering the tone again )

You will find the rails now slide an extra few inches further forward. More than you will actually get when the seat is put back in the car, as the seat will be stopped by the rear of the transmission tunnel.

You can now bolt the seat back into the car, loosely fitting the rear torx bolts first, then the front ones. You'll need the lolly stick to raise the plates again for the bolts to catch in the threads. I took the opportunity here to use both the rear spacers and the front spacers on the front bolts between the floor and the rail to raise the front of the seat slightly to give a little more support under the thighs. This is optional.

Sorry this has been a bit long winded. A picture would have saved a thousand words, but it does all become clear when you have the seat out.

The mod gave me about 1 1/2" extra legroom which made my driving position much more comfortable on a long run.

Kind regards,
Glenn.

Many thanks guys! I'll give the idea more thought - the last thing I want to do is give my myself the problem of losing the plates in the abyss or my balls!!

Brian