Bolts for shock absorber/spring replacement (multilink)

[Fritura]

Hi there! I’m planning to replace my rear shocks and springs on my fwd 1.8 Tsi (multilink rear) and looking for some advice regarding parts, and will welcome any tips

I’ll compress the spring to fit and refit and I think this way I can avoid undoing the eccentric bolt at the inner end of the transverse arm.

I’m aiming to reuse the bump stop, dust boot, and the top and bottom spring seats but I will need to replace some of the bolts-

• Two top mount bolts at top of each shock
• The bolt and nut at the bottom of the shock
• The bolt and nut that connect the ARB drop link to the transverse arm
• And, as I am also replacing the spring, to drop the arm adequately i need to remove and replace the bolt and nut that connect the wheel bearing assembly to the transverse arm .

Just wondering Is there a sensible and economical way of obtaining these bolts? Main dealer? I will appreciate all tips!

 

[nd-photo.nl]

My 2 cents:
- Replace the arms if they have signs of rust
- Replace the eccentric bolts, as they need to be loosened for the alignment afterwards. These are available aftermarket
- Replace the top mounts, I reused the bolts no problem (add a small dab of threadlocker)
- Don't skimp out on the bump stop, dust boots & spring seats: aftermarket = cheap replacements
- You don't need to use spring compressors, but it can be a little easier
- You can reuse most of the bolts no problem, if they are heavily corroded or if the heads are mangled, just replace them (via dealer)

Optional / while-you-are-in-there
- Replace the rear wheel bearings
- Replace the headlight height sensor
- Replace the rear droplinks

 

[Fritura]

Thank you @nd-photo.nl, these details are really helpful!

Just one thing - some of the bolts, according to Erwan, are specified as X Nm + 180°. Whilst I could easily be mistaken, my understanding is that bolts tightened using a torque-plus-angle procedure like this can be “stretch bolts” and may be single-use only. No sure if this is the case here?

 

[James_R]

Stretch bolts with an additional turning angle are single use.

 

[nd-photo.nl]

@Fritura They are single use, but you can reuse them, although it will be always better to replace them. The choice is up to you

 

[Fritura]

Thanks for your input guys - much appreciated. Bolts on order from main dealer

 

[SuperV8]

Why are you replacing your springs?
Personally I would only replace them if corroded or sagging (determined by measuring ride height)
When I changed my rear shocks, the springs were fine. Shocks were knackered!

 

[Fritura]

@SuperV8 - yes, agree. Mine has rear right spring broken at bottom, otherwise I would just do the shocks.

Second photo shows rear left shock- I gather that some misting on the shock is normal, but I think this is more of a leak than a mist?

 

[DaveS]

@SuperV8 - yes, agree. Mine has rear right spring broken at bottom, otherwise I would just do the shocks.

Second photo shows rear left shock- I gather that some misting on the shock is normal, but I think this is more of a leak than a mist?

That is how the rear shock on my car looked when they were changed. The difference in handling was very noticeable.

 

[nd-photo.nl]

Looks more like leaking than a mist indeed. You will notice the difference for sure after they have been replaced

 

[Fritura]

Thanks for the encouragement Looking forward to experiencing the results!

 

[Fritura]

Just wondering whether anyone happens to know the OEM manufacturer of the rear springs? Mine are part number 5Q0511115FJ

 

[SuperV8]

Just wondering whether anyone happens to know the OEM manufacturer of the rear springs? Mine are part number 5Q0511115FJ

There are loads (30+ from memory) of spring OEM numbers, depending on exact spec and PR code, any aftermarket spring you get with be either normal or sports - so the only way to get exactly the same as your original spring is to buy the original from Seat.
Even if you found out who was the OEM manufacturer for your spring they won't sell 30+ versions into the aftermarkt.
The OEM springs aren't that expensive, though the rears are quite easy to change if you did go aftermarket and they get give you the wrong ride height - just make sure they have a good returns policy!

 

[Fritura]

Very interesting @SuperV8 - thanks! I've learned something new here. I'd assumed the matching aftermarket part number means an exact match but I can see now that some aftermarket springs map to several OEM part numbers. I shall select with caution and post the results here in the coming days...

 

[Fritura]

Update:

I successfully replaced both rear springs and shocks and I must say there is an incredible improvement to handling and to ride quality over big bumps.

I followed the process as described in Erwan and it was reasonably straightforward other than a couple of mild irritations – first a wheel liner torx bolt was corroded, and second it hard to turn the last 45 degrees on the upper shock bolts due to access under the wheel arch and the size of my wrench.

I swapped over the top mount from the old shock to the new using a deep ring spanner and adjustable spanner.

I did not need to compress the springs though it might have made it slightly easier to line up the bolts on the transverse link. Jacking up the link to precisely the right height made it easy enough to remove and refit the bolts, and each bolt went in feely when jacked up to its own particular sweet spot.

My local main dealer was helpful in sourcing the replacement nuts, bolts and spring seats.

Upper spring seats and bump stops were in good shape. The lower spring seat was in poor condition owing to the fractured spring. Both shocks were well past it, with no gas pressure and inconsistent damping due to lack of oil and air entrainment in the piston.

With the aim for OEM-equivalent parts I used Bilstein B4 shocks and Lesjofors springs.

A vast improvement to handling was immediately apparent – more taught and less bounce, less rear lift on braking and less squat on acceleration, no more bucking over speed bumps and improved composure through corners. All this noticeable on ordinary, everyday driving.

Ride height after a week and a few hundred miles: I measured 365mm both sides (with a full tank) vs 366mm spec – spot on I’d say

Thanks to contributors in the posts above – I am grateful for your support and I am very happy to have completed this job!

 

[nd-photo.nl]

Well done, and basically describes my experience when refreshing the rear suspension Enjoy your better driving and safer car!