Hi to you all out there.

I am wanting to raise the back-edge of the drivers seat so that I can put a couple of 12mm spacers under the rails.

I have removed the bolts- two in the outer rail and one in the inner rail but the rails will not lift much at all.

apart from at the very front of both rails is there anything else that is would prevent the rails from allowing the sliding in of the spacers ?

 

I have achieved this very same operation on at-least the last six cars that I have had - BMW's,Mercedes SLK's and a Mercedes C220 CDI.

 

I am puzzled.

Morning John

There should be 4 M10 bolts holding the seat rails to the floor ? So if you have only taken 3 out no wonder you are having trouble 😆

Will the seat height adjustment not give enough lift?

Dave

9 hours ago, Greydog said:

Morning John

There should be 4 M10 bolts holding the seat rails to the floor ? So if you have only taken 3 out no wonder you are having trouble 😆

Will the seat height adjustment not give enough lift?

Dave

Hi Dave.  Thanks for coming back on this one.

As I quoted in my opening post there are very clearly only three bolt-heads visible - with the seat adjusted forward to the max. When viewed from behind the seat the right-hand rail has two bolts and the left-hand rail has one only !

Upon closer investigation - yes there appear to be two other bolts - one in each rail at the front of each rail with black plastic caps covering the heads ! I would not have suspected that the two front bolts would have had such an amount of holding-down power

I will try loosening them and see if that gives the rails enough clearance so that I can slide the spacers under the back edge of each rail.

 

The seat height is adjusted to its maximum but the aim is to gain a further half inch or so at the rear only.

 

I stand at 4'10" but with a 23" inside leg measurement  and a slightly short torso.

I have an hereditary condition that leaves me 8"/9" shorter than I should be - very good in the days of my competition judo activity.

Hi again Dave.

I have looked at the two front rail fastenings and they are not bolts that I can partially undue - they are actually short lengths of stud with a hexagon nut on each ! - something that I have never ever seen before.

I will leave well alone until I have researched the issue a little further.  

Morning John

Have you looked at www.realoem.com it should let you see where the fixings are and what they are for your model

Dave

Hi again Dave. I have identified that there are Five fixings that secure the drivers seat to the floor-pan.

Three are 10mm bolts (two in the outer rail and one in the inner rail) and the two at the front are studs with hexagonal nuts leaving a very short amount of thread above each nut.

 

The link that you sent me  cannot identify the parts nor the locations without a factory correct description of the items.

 

I cannot adjust the seat any higher than I have so I will cease trying and just accept that this is the best that I am going to get.

 

Morning John

To use realoem you need to put the last 7 Digits of your Vin Number into the search box it will bring up your model, then look at the seat section. I have just done that without your Vin and attached is the Diagram it tells me item 4 is an M10 bolt and there should be 3 Item 6 is an M10 Hex nut ribbed and there are 2 with cover caps.

So either slacken off the nuts or remove them and your there 

Dave

5 hours ago, Greydog said:

Morning John

To use realoem you need to put the last 7 Digits of your Vin Number into the search box it will bring up your model, then look at the seat section. I have just done that without your Vin and attached is the Diagram it tells me item 4 is an M10 bolt and there should be 3 Item 6 is an M10 Hex nut ribbed and there are 2 with cover caps.

So either slacken off the nuts or remove them and your there 

Dave

Hi Dave. I did exactly that using my last seven digits (B705166) There was also a second box - PART NR APPLICATION SEARCH which was a bit strange because that was what I was researching !

In my previous reply I pointed out that item 4 actually came up as three - two on the outer rail and one only on the inner rail at the rear in both cases.

Item 4&5 repeat on both rails at the front - they are the ones that there is a short length of stud that would be left in the floor-pan if the hex nut was removed !

I do not wish to remove the nut because I no idea how the stud is secured in place - CAPTIVE but how ? - surely the two single hex nuts cannot be what is preventing the rails from raising a mere half inch it the very back so that the spacers can be positioned and then the bolts can then be reinserted !

 

Hi John

Seats are heavy even more so if fully powered the fixings have to be able to contain tons of force in the event of an accident and not break free. Those fixings will hold not just the seat but a very large person, where they mount is heavily reinforced so the studs will definitely stop the seat lifting at the rear particularly as the seat runner profiles are designed not to deform/bend in just such a scenario as having a missing fixing. If your worried slacken the nuts but don't take them off the stud that should allow you to lift the rear about an inch or so. 

Dave

3 hours ago, Greydog said:

Hi John

Seats are heavy even more so if fully powered the fixings have to be able to contain tons of force in the event of an accident and not break free. Those fixings will hold not just the seat but a very large person, where they mount is heavily reinforced so the studs will definitely stop the seat lifting at the rear particularly as the seat runner profiles are designed not to deform/bend in just such a scenario as having a missing fixing. If your worried slacken the nuts but don't take them off the stud that should allow you to lift the rear about an inch or so. 

Dave

Hi again Dave. I suspect that if I keep the car that I might have the seat height increased by visiting a motor trimmer and getting a 1" pad of high density  (reconstituted foam) inserted beneath the existing fillings and the seat cover replaced so that there is no obvious difference in the construction.