Boxer Rear Clamshell Gas Struts

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 ~~~~~~~

Thoughts?
Thanks

 

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

 

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

 

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.

 

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:

https://www.ferrarichat.com/forum/threads/i-cant-keep-it-up-the-front-hood-shocks-i-mean-the-front-hood-shocks.616344/page-2#post-147039146

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.

Cheers,

Sam

 

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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just ordered a set- in by Friday!

 

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.

 

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

 

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 .

 

For info and future reference:

To anyone that needs new gas struts for the rear end on the 512BBi, these will fit:

1984, 512BBi, rear engine lid gas strut: Stabilus Lift-O-Mat gas spring type 083836 300N, angle/angle 08 220 0300.

Warning: The gas struts sold from SuperFormance and Marenello parts UK for 512BBi rear end do NOT fit.

Best Regards Peter

 

Tag for future referance

 

You are correct! I finally got around to opening the Maranello rear deck struts, and they looked a bit long. So after careful measurements, I realize they wont allow the deck to close without bottoming out. Not a good situation.


Where did you get your "Stabilus 083836 300N, angle/angle 08 220 0300" gas struts?

Thanks!

 

Yes I’m right. I informed SF accordingly but they didn’t seem to care. I bought the struts locally in Denmark. They, and other brands, seems to be readily available many places.



best, peter

 

Hi Peter,
Shame about SF. I generally hold great appreciation for SF and MC and am thankful for the great stuff, and patient and understanding when it's not great. We must always remain vigilant and protective of these beautiful rolling sculptures. MC knows of the issue now and are looking into it and hopefully will sort it out.

I just bought some new struts through stabilus that have the part number you provided. Great-great job by the way Peter spec'g out those struts. Stabilus makes so many of these it's a bit of chore to find the right one. Using one that is too long could result in terrible problems, maybe even hurt the sheet metal where the strut brackets attach? Not good at all.

Best regards
Bruce

 

I bought the struts from here and they were on the shelf:

https://www.elektronico.dk/produkter/lineaerteknik/stabilus-lift-o-mat-gasfjedre/04083836

Best, Peter

 

I once used also the stabilus, but not long time. it was told me that the stabilus are not for horizontal mounting and after about 2 years they not worked anymore

 

Agreed. Long lasting is not their best quality.

Almost afraid to ask ~~~ Anybody change the front ? I tried compressing the original rear struts by hand. Supposed to be ~60 pounds, I doubt 10. Now I wonder if the front shouldn't open easier. BTW - The parts book calls out the same part number.

 

We've been here, though not for years:
Boxer Rear Deck Lid Struts/Shocks

I had LST recharge/reseal mine, as several others here have, so you retain the original factory mounts, and markings.

 

once ago someone posted struts with livetime warranty, but can not find this post anymore
who can help?

 

I just received the new Stabilus ones by part number provided by Peter (Thank you again). The length and fittings look spot on. The traditional white silkscreen markings have been replaced by a large white Stabilus sticker. Also, the paint was satin, now it's gloss, and the diameter of the cylinder is slightly larger (0.75" -> ~0.81"). But it does come with identical fittings and clips. The force on the original is 280N, the new ones show 300N (~4.5lbf increase).

Wowwwwww!! I just installed them. What a huge difference. I've owned the Boxer 13 years and now realize the struts were dead all along. I always thought the super heavy opening of the clamshell was supposed to be like that. Some rite-of-passage to owning one of these beasts. Now I realize, it was just a pair of dumb aged-out gas springs. Now I got to attack the front ones 'cause I'm certain they aren't doing what they're supposed to.

I might give Strutwise a shot at rebuilding the front struts. https://strutwise.com/contact-us/ I learned about him on F-Chat.

BTW: MCL returned the deck struts which were too long, and told me they have a sourced the correct ones.