Boxer Rear Clamshell Gas Struts

Discussion in 'Boxers/TR/M' started by 2dinos, Jul 20, 2020.

  1. 2dinos

    2dinos Formula 3

    Jan 13, 2007
    Interesting that the 308 gas struts seem to have a finite life (Not terrible, but I've changed 3X maybe 4X in 30+ years), and the BB seems to be good(?). Here's my concern. On the 308, there is no over-center effect on mechanical advantage. Struts lose even a little strength to support the load, and it falls. Simple.

    On the Boxer, when the deck is up, it's pretty much vertical, and the center of mass moves very close to inline with the pivot (Hinges), so the struts can get weak and you might not notice as the clamshell is a fairly hefty piece of hardware anyway. So I'm wondering if it might be more secure w fresh ones and a bit easier to control? Maybe even be more gentle to the precious car if they are fresh.

    Anyone had their struts go dead flat and clamshell wouldn't stay open?

    I had it open and there was a strong breeze and it made me think ~~~~~~~

  2. pshoejberg

    pshoejberg Formula 3
    Silver Subscribed

    Dec 22, 2007
    Full Name:
    Peter H
    Mine are still the original but they are becoming so weak that I don't park the car up wind and I use a ''safety support broomstick'' when I work on the engine. New ones are on order from Superformance and they don't cost a lot. Unfortunately the new ones are aftermarket parts without the Ferrari name on them as on the original.

    Best, Peter
    2dinos likes this.
  3. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    southwest germany
    Full Name:
    romano schwabel
    once someone has posted here in this boxer/TR/M section long time ago such struts with livetime warranty. can not remember when it was and who posted it, but those struts I would order.
    on my TR I need struts every 3-5 years, front and rear. terrible :(
  4. 2dinos

    2dinos Formula 3

    Jan 13, 2007
    Thank you guys! Exactly what I was talking about. I have this hunch they're weak. Flat ground, no wind, all is fine and they seem to work, but I think they should be a little stronger. And yes, mine too are original with the cool writing on there. Oh well.
  5. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day,

    I posted a few times about my experience about getting some replacement struts made for my Boxer and my 365 GT4 2+2 and I cannot say enough at how happy I am with the results. The most recent post was early this year:

    You can also search for my original post way back in 2006.

    In a nutshell my original Boxer struts were knackered and at the time (2006) they were NLA. I ended up finding a place that could recharge my struts and if not they could recreate a set. Sadly, my originals were too far gone and the internal seals could not be found and so the shop created replacements and they worked fantastic! Since the shop had not made a set for a BB before, I worked with them to find the appropriate force, travel, etc needed. Secondly, the shop modified the internals so that the strut would behave differently depending where it was in the travel. For example, the strut provided maximum force when just starting to open and then slowly reducing the force and acceleration until the clam is fully open. This ensured that the clam does not "snap" open causing undo stress on the clam, hinges, etc.

    I installed these in 2006 and they are still working perfectly. Given my experience with the shop and now knowing what can be done with these struts, there is simply no way I would consider using off-the-shelf generic struts... and best of all the price for the struts was extremely reasonable and to me low cost.


  6. Drew Altemara

    Drew Altemara Formula 3

    Feb 11, 2002
    Tuscaloosa, AL
    Full Name:
    Drew Altemara
    I've replaced mine; 79 carbed boxer rear clam shell struts. David Feinberg was good enough to supply the part numbers and they look and work perfectly. These are from McMaster-Carr products. They are not expensive. However it is from 2008. Drew
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  7. Ludwig

    Ludwig Formula Junior
    Silver Subscribed

    Mar 27, 2006
    Redmond WA
    Full Name:
    Ludwig Allegra
    just ordered a set- in by Friday!
  8. 2dinos

    2dinos Formula 3

    Jan 13, 2007
    Wish I'd seen the McMaster option sooner. I ordered some replacements from Maranello Concessionaires. They do a good job with original, or their Maranello Approved parts. I hope the difference is obvious and for the better.
  9. Nate365

    Nate365 Rookie

    Oct 9, 2005
    Northern VA
    Full Name:
    Nate Stevens
    Having grappled with this exact question recently, thought I'd provide some images and offer comments regarding fit on the FRONT hood of my 365. Unfortunately it's still too early to fit the rear deck so this is a partial response only!

    I first purchased the 50lb units from McMaster, due largely to the great price. OEM parts were 26.9" extended, the McMaster strusts where 28" - not a massive difference although the mount geometry exaggerates any delta when the hood is fully 'open'. Not a big deal, just irked me a little. The real concern was they were (imo) way too strong, especially at the top end of travel. I had to use a cord, tied to the catch hook, to help control things as the hood arched upward. It seemed much like restraining and angry mule with a small lasso - - - definitely no bueno!

    So the McMaster struts came off and the LST unit went on. They worked beautifully, I'm sure the neighbor heard my sigh of relief.

    The photos show both aftermarket units alongside the OEM strut (OEM in the middle). The LST strut is about 26.5" extended. I used heli-coils in the stock strut 365 ends to adapt them to the new hardware. Neither aftermarket strut has the same proportions of the original, but at least the rod on the LST unit has the normal chrome appearance.

    The McMaster units were marked "50 lbs" and this checked on a my crude bathroom scale test. I think the difference is that the LST version offers less force (and/or some additional dampening?) as it nears full extension.

    Clearly this is just one data point, hopefully there will be reason to test the rear strut application in the relative near future. Regards, Nate

    Attached Files:

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  10. 2dinos

    2dinos Formula 3

    Jan 13, 2007
    Thank you for the beautifully detailed findings. Very nice how that fitting threads on the strut ends. I wonder if the geometry of the 365 is same as 512. On the 512, there is a snap on spherical attachment and retaining clip. Just received the replacements from MC and haven't put them on yet. Really need an excuse to take it for a drive. Test out the new struts :rolleyes:.

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