NCV3 Lumbar Support Fix

Upon receiving my Sprinter (used 2008 170 Cargo) The manual knob for the drivers seat lumbar support would spin freely through its range of motion, but would not notice any effect on the lumber support. The passenger seat worked just fine.

I have basic cloth seats. I am not familiar with all the options out there, so I am not sure how this might apply across the board. I am fairly confident I have a basic seat option available on freightliner cargo's in 2008.

Steps to fix.

You will need to remove the arm rest and side knob.

Pivot the seat back as far forward as is needed to expose the underside to the back of the seat (the crease where it meets with the bottom cushion)

You will notice a couple pieces of plastic running the full width of the cushion.

Upon inspection you can see how these clasp together. Undo the clasp and the seat cover should be free to pull upwards.

Pull the seat cover upwards at least half way and remove the cardboard backer noting its orientation and position in the seat back.This should expose the guts of the seat in the lumbar area.

What you will probably find as I did, is a cable attached to the lumbar adjustment know that should be attached on either side of the seat back frame. However I noticed the cable was not attached on the opposite side of the knob.

I found an S shaped piece of cast aluminum that was snapped in half. This S shape used to go through a hole in the seat frame. As the knob is adjusted, this cable tightens or loosens giving you your lumbar support.

Since I had a bulky chunk of material left at the end of the cable, my simple solution with parts I had available, was to take a stainless steel S hook (used for hanging plants) And close one end around the cable of this mechanism so that it couldn't slip past what remained of the old attachment.

I then fed the other end of the S hook through the appropriate hole and closed it down a bit. You may have to move some seat foam to access the hole.

I then tested operation and reassembled in reverse.

This is a very simple fix. Happy to have my lumbar support now! I might open everything back up and adjust it a bit tighter for even more control. This fix did replicate the support from the factory, I would like to try a little more.

Hope this one helps someone else out.

Erik

This has been worrying me even though we bought our new a month ago. I figured it will break sometime in its life, so it's nice to see it's not too complicated a task to fix the lumbar support.

I had to fix the lumbar support on a 240 Volvo for both front seats. What a wretched process! Bunch of plastic and thin wire that breaks too easily and if any little piece gets brittle, it's all falls apart. To put the seat fabric back together, hog rings are used and they can be a little difficult to work with when reassembling the seat.


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Great write up! Just fixed our 08 sprinter's driver seat which had the exact same issue. It was nagging me for weeks and had even considered buying a new driver seat. Thanks

I inserted a 2cm thick piece of foam between the wire skeleton and the back foam padding at the bottom for the last 20cm as a lumbar support. In the driver and passenger seat.
In this case a leftover of self-adhesive 20mm insulating foam.
Since then, the sitting position and the back relief have been significantly better.

Can you share how the seatback opens up like that? I haven't needed to open mine yet but it'd be nice to know how its done.

Hi freedomsprinter
That's easy.
First unscrew and pull off any existing armrest.
Pull out the headrest, from behind the seat.
Then, also from behind the seat, starting from one side on the underside of the back part, use a screwdriver to pry apart and separate these two black plastic clip strips.
And you can pull up the back cover piece by piece to the top.
Now you can remove the back cardboard from behind inner and the black cover in the upper section. Behind are the two black dowel inserts for the headrest. These can be carefully driven out upwards with a hammer.
Now you can completely remove the back cover, the foam padding can be removed from the metal frame and you have the wire skeleton free.
Assemble in reverse order.
The first time it is a bit fiddly to close the two clip strips against each other again. Again, start from one side and like a zip-lock bag clip the two strips togehter.

Very helpful explanation and photos.

Thank you!

sprint2freedom said:

Very helpful explanation and photos.

Thank you!

Click to expand...

PS: Now its the right time for giving the seat and back cover in the washing machine by 30° C.
Let it dry completely in the sun, not tumbler !
Your seats will look brandnew!