Mercedes Sprinter Front Spring Replacement

 

 

If your sprinter has dropped on one side at the front there is a likelihood that one of the two leaves on the transverse leaf spring across the front axle has broken.

Mercedes Sprinter front spring broken

Mercedes Sprinter front spring broken

To replace this spring is not for the faint hearted and needs a good tool kit with some heavy bars and pry’s to complete.

Here is what you do: It is worth remembering that the manual will have you stripping far more components down than you really need to complete the job, so here is the minimum that you will need to do.  It will take you 5-6 hours to complete so set aside a good weather day to do the job –  it is unpleasant enough without it raining on you too.

With the vehicle on the ground crawl under with an 18mm spanner and 19mm socket and breaker bar, juggle the open end of the spanner into the small gap between the cross member wishbone support and wishbone pivot.  Beneath both front and back wishbone pivots you will find a 19mm bolt with 18mm nut, whilst locking it as above, crack and remove these 2 pins on either side of the Sprinter – OSF and NSF.

Loosen the wheel bolts of both front road wheels then jack the vehicle front and support the body at a suitable working height with stands.  Remove the front wheels.

Split and separate the NSF steering ball joint from the hub assembly.  Remove the three 16mm pins that hold the spring locator plate to the top of the wishbone, and pivot the plate away from the spring end and work area by spinning it on the roll bar link bush. (No need to remove these)

Sprinter Front Spring Swap

Sprinter Front Spring Swap

Remove the other 16mm pins from the spring locator plate on the OSF and move it out of the work area in a similar fashion to the above.  Now remove the remaining 4 spring clamp plate bolts on the OSF (19mm pins and 17mm nuts) from the sub frame and remove the plate completely.  Note the plate locates on two dowel type spigots on the front and rearmost bolt holes and these need to relocate on assembly for correct fitment.  As you dismantle the plates/spring you will need to recover and note the location of 4 rubber buffer blocks – 2 above the spring and 2 below.  Use a jack and wooden block to support the spring under slight holding pressure before continuing.

Undo and remove the two lower wishbone pivot bolts on the OSF.  Inside the cab by the accelerator, remove the 24mm top strut/damper bolt by holding the shaft with a hexagon key and using a ring spanner.  Support the complete hub assembly on a jack and remove the damper top bolt completely.  The hub assembly will now be floating, using a small crow bar free the lower wishbone from the sub frame.  Ensure the brake hoses and sensor wires/cables do not get strained or snagged during this process.

Sprinter lower wishbone / spring retainer

Sprinter lower wishbone / spring retainer

Pull and rotate the OSF wishbone/hub out of the way enough to the rear of the vehicle to allow clearance to lower the spring. Lower the jack supporting the spring.  It will tip down on the unsupported side and fall clear of the OSF wishbone and hub.

Move the jack the other side and lightly support the spring (that will have now lifted up from the cup on the NSF wishbone) Undo the remaining 4 spring clamp bolts and remove the plate, lowering the spring again once removed.  With care the spring can now be manoeuvred out of the NSF wishbone cup and slid out from under the vehicle.

Sprinter Front Spring Swap

Sprinter Front Spring Swap

The new spring can be slid into place in the same manner; supporting its weight with the jack and wooden block once more it can be retained and held back in the correct position while the NSF clamp plate is re-bolted into place.  Making sure that as you proceed the 2 rubber buffers (a pair on each side) are located correctly top and bottom with a torch and inspection mirror before moving to the OSF.

Now jack up the free end of the spring on the OSF, again check the location of the upper rubber buffer into the cup on the sub frame. (The sub frame upper buffer locator cup is made from hard Nylon and on the driver’s side it is coloured Red, the passenger side colour coded White – there is different spring preload for the driver side to compensate for his weight in a balanced vehicle)

Once happy the spring is in the correct position, reposition the OSF lower wishbone under the spring and relocate and fit the 2 wishbone pivot bolts.

Loosely reposition the OSF and NSF spring locator plates on the tops of both wishbones, beginning to trap the spring at its ends into the wishbone arms, finger tighten the 3 pins in each sides triangular plate.

Extend the strut/damper on the OSF and wrap rag around the shaft. Use light mole grip pressure through the rag to clamp the damper rod fully extended, to prevent it retracting as you guide it back inside the cab.  Use the jack beneath the hub assembly to raise it into the correct position so you can easily re fix and tighten the 24mm bolt on the damper rod.  Working beneath the OSF wheel arch rebuild the spring clamp plate and fully fasten the three 16mm pins that trap the spring to the top of the wishbone.  Lower the spring supporting jack and recover the second jack that was assisting to hold the OSF hub.

Underside of donor subframe showing spring clamp plates and wishbone configuration

Underside of donor subframe showing spring clamp plates and wishbone configuration

On the NSF refit and tighten the track rod ball joint, fully tighten the three wishbone triangular plate bolts and fit the road wheels then lower the vehicle to the ground. Torque the wheel nuts and replace trims.  With the vehicle under its own weight crawl back underneath and replace the final 2 fixings to the spring clamp plates on either side.  NB. If you do not remove these 2 pins on either side before jacking the vehicle you will be unable to do so, as once the wishbone lowers under spring pressure when jacked – the access gap is closed and you will be unable to back the nut with a spanner to remove the bolt.  It is obviously impossible to refit these bolts until the vehicle is once more on level ground under its own weight.

The job should now be complete, road test the vehicle and be very pleased with yourself.

 

11 thoughts on “Mercedes Sprinter Front Spring Replacement

  1. Thanks for the info. Job went well apart from needing a second set of hands when fitting the wish bone back onto the vehicle.

  2. Thank you, great instructions, just did this job on chassis stands on my vwlt28, took a day and lots of scrabbling about on the floor but done now!

    1. Hi Sam,
      Fantastic that you found it useful. Its a straightforward job just big scale and a little mauling on your own. Glad you are sorted.
      All the best
      Steve

    1. Hi James,
      Off Side Front, Near Side Front in respect to right hand drive vehicles here in the UK. This equates to universally: OS = Right hand side NS = Left hand side
      Regards
      Steve

  3. Thanks for this information, what is your opinion on replacing the front leaf spring with a double leaf spring? Does it affect the drive, especially if I haven’t upgraded the rear? Many thanks 🙂

    1. Hi Steve,
      Either design is good – the original dual leaf steel or composite fibre spring used in later models. I would stick to what was fitted as standard however, as ride height may be affected – you may need a different size range of ‘support packings’ for above the composite/steel spring you change to.
      All the best
      Steve

  4. Excellent ..thank you. Needed van for new job on a monday when spring broke few days previous. Couldn’t get a garage to sort it in time so with your instruction tackled it and it went well. Great knowing what’s required beforehand. Thank you for taking the time to put this article together.

  5. Excellent …Needed van for new job on a monday when spring broke few days previous. Couldn’t get a garage to sort it in time so with your instruction tackled it and it went well. Great knowing what’s required beforehand. Thank you for taking the time to put this article together.
    Cheers
    Danny

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