4200: Wanted Used/Blown Skyhook dampers

[FIFTY]

Hi everyone

Looking for a used skyhook damper - it can be blown/leaking

Happy to pay for it or donate some money to your chosen charity

Full disclosure talking to a company about getting these rebuilt and I want to give them a sample to work with and test thoroughly prior to sending off the ones on my car for restoration. If it works then I will pass all of the information back to the community to hopefully help others out

A failed one would be a good place to start

 

[jasst]

Hi everyone

Looking for a used skyhook damper - it can be blown/leaking

Happy to pay for it or donate some money to your chosen charity

Full disclosure talking to a company about getting these rebuilt and I want to give them a sample to work with and test thoroughly prior to sending off the ones on my car for restoration. If it works then I will pass all of the information back to the community to hopefully help others out

A failed one would be a good place to start

Hi Shog, I have a knackered one you can have.

 

[FIFTY]

Hi Shog, I have a knackered one you can have.

That's fantastic, thank you so much

Shall I collect it at the Haynes breakfast club?

As I mentioned happy to donate some cash to your favourite charity (even if that's your Maser fund) when I pick it up

 

[mjheathcote]

There was a Maserati breaker that at one stage offered a reconditioning service.
Not sure what happened to them though.

 

[FIFTY]

There was a Maserati breaker that at one stage offered a reconditioning service.
Not sure what happened to them though.

Greg Smith at Premier Performance Parts - he's a forum sponsor. Not actually bought anything from him yet but he has been very prompt and helpful whenever I have contacted him

I messaged him the company he was using no longer offers that service

 

[philw696]

Had my rears rebuilt when in New Zealand.
It's the machine work that costs the money.
Once that has been done they can be rebuilt several times.

 

[FIFTY]

Had my rears rebuilt when in New Zealand.
It's the machine work that costs the money.
Once that has been done they can be rebuilt several times.

Interesting comment there Phil - would you say that they were not designed to be rebuildable?

 

[philw696]

Interesting comment there Phil - would you say that they were not designed to be rebuildable?

Yes they were never meant to be rebuildable as they are sealed units.
The Guy we used in Auckland was a authorized agent for the likes of Ohlins and did a lot of motorcycle stuff.
I wish I had taken some pictures of what he did but I didn't.
When I was at the Dealership he did quite a few for us and Ferrari ones too.

 

[FIFTY]

Yes they were never meant to be rebuildable as they are sealed units.
The Guy we used in Auckland was a authorized agent for the likes of Ohlins and did a lot of motorcycle stuff.
I wish I had taken some pictures of what he did but I didn't.
When I was at the Dealership he did quite a few for us and Ferrari ones too.

Cheers Phil. I will mention that to them...

 

[Oishi]

Hey Fernando, I have looked into it also. There is a video on utube showing the machine work needed on a Sachs motorcycle shock of similar design. A port to decompress the nitrogen must be drilled and tapped, then the top machined off to get to the seals and valves. The top is then threaded for reassembly. After that, it's a matter of replacing worn parts , assembly and recharge with nitrogen.

 

[jasst]

That's fantastic, thank you so much

Shall I collect it at the Haynes breakfast club?

As I mentioned happy to donate some cash to your favourite charity (even if that's your Maser fund) when I pick it up

Don't want anything for it, happy for it to be used in the battle to keep these cars on the road, yes will bring it to Haynes (you may have to remind me just before Lol)

 

[FIFTY]

Thanks again @jasst

@philw696 did the place in NZ have the ability to adjust them electronically when they dyno tested them after servicing?

 

[philw696]

Thanks again @jasst

@philw696 did the place in NZ have the ability to adjust them electronically when they dyno tested them after servicing?

I don't think they did but working at the Dealership we had the Diagnosi so could access the control unit.
Never had an issue with any i fitted.

 

[Mr S]

On a tangent path, but was on my to do list to contact https://www.raceshocks.uk/wp-content/uploads/2020/10/Coil-Over-Buyers-Guide-October-2020.pdf in regards to looking at a set up to cover both bases/happy medium of Sky Hook. Maybe more a UK based problem, but knocking the edge off Sky Hook for us would be great benefit.

 

[Oishi]

I don't mean to hijack the thread but,
There is a cryptic mention on
Maserati 4200 / GranSport: F.A.Q. (checkvist.com)
That references a thread on ML about failing Skyhook dampers due to lowering of suspension.
This might be part of the reasoning behind my long ago comment about the Skyhook system learning how we drive.
If the system only has 2 settings, soft and firm, why would lowering the ride height (and taking preload off the springs) make the dampers fail trying to compensate?

 

[Zep]

I don't mean to hijack the thread but,
There is a cryptic mention on
Maserati 4200 / GranSport: F.A.Q. (checkvist.com)
That references a thread on ML about failing Skyhook dampers due to lowering of suspension.
This might be part of the reasoning behind my long ago comment about the Skyhook system learning how we drive.
If the system only has 2 settings, soft and firm, why would lowering the ride height (and taking preload off the springs) make the dampers fail trying to compensate?

To me, that doesn’t add up.

The system measures the yaw and closes a valve in the piston reducing flow from one side of The piston to the other. It’s not clear how this solenoid can be over worked given that it is designed to work on a pulsed signal.

Given that most dampers fail due to the seal around the piston rod and leaking, this sounds unlikely.

 

[Oishi]

Thanks Zep, I am also questioning how a change in spring load would cause the seals to go on a damper. But without seeing a dynograph of a Skyhook shock for bounce and rebound, and seeing the algorithm that controls the valving, the only way I can think that this would be possible is for the computer via the vertical accelerometer input to stiffen the bounce to try to compensate for less spring. I remember thinking about how I would write the algorithm in order to bias the data stream towards the latest inputs, in short, make the system learn.
But if the Skyhook doesn't compensate, how can a change in spring, cause failure?

 

[Zep]

I think the point is, even if it did learn, how would closing or opening the valve in the piston cause the top seal to fail? A much more likely correlation is that cars of a certain age are more likely to be modified in this way.

Anyhow, I am watching this with interest. These sorts of projects are why I think this forum is second to none.

 

[Gazcw]

I think the point is, even if it did learn, how would closing or opening the valve in the piston cause the top seal to fail? A much more likely correlation is that cars of a certain age are more likely to be modified in this way.

Anyhow, I am watching this with interest. These sorts of projects are why I think this forum is second to none.

I will let you know when mine falls apart

 

[Oneball]

You can damage dampers on lowered cars (in general) what happens is the damper bottoms out and damages the valve at the bottom of the tube. Usually because the bump stops have been cut or damaged after being struck so often.

It is possible to split a welded damper. You would cut the body and then thread a top cap (and install a gas port if they’re gas filled) so you can rebuild them.