LS4 Landing Gear Gas Strut Replacement

[John Usher]

I’m having a difficult time trying to find a direct replacement for the Stabilus 047708 Gas Strut as well as the Stabilus (Miele?) 1448DX Hydraulic Damper for my LS4 landing gear. Any suggestions?

Thanks,
John U.

[Dan Marotta]

There are shops that will make a gas strut to your specifications.
Someone here will point you there sooner or later.

What I did was note the numbers on my gas strut and then search the net
for a cross reference. Mine turned out to be one of the hood (bonnet)
lift struts for a mid-90s 6-series BMW car. Got it over night at Auto
Zone for around $30.

Dan
5J

[Mike]

John, go to the website at stabiluscom. You can input a part number to search for more information. If that doesn’t yield results, contact the rep for your area. The one on the east coast cross referenced the damper in my 1978 trailer to a Volkswagen steering damper.
Mike

[John Usher]

Thanks Dan and Mike.
I have tried all suggestions, Google searches, cross references, Bansbach, Stabilus (Gas Supply Shop), Industrial Supply (Sodeman), Granger, McMaster, a couple of European suppliers , etc, etc, but no luck. There are a few that “closely” match but none that are exactly the replacement specs for the landing gear gas strut. I’ve had zero luck trying to find a hydraulic damper replacement, not even a “close” match. DG apparently has them but I can’t justify paying $500+- for the service contract just to buy a part that only costs about $50.
Best Regards,
John U.

[Dan Marotta]

Go to one of the many suppliers and look for a strut that matches the
compressed and extended lengths of yours and get the next one up in
pressure. You may have to push or pull a bit harder on the lever to
raise and lower the gear, but that'll simply make you a bit stronger!

And don't forget to match the end fittings or you'll need to find a
friendly machinist to make the parts fit. I've done that on other parts.

Dan
5J

[SF]

Try:
Henk Blok
Gemini Gas Springs Inc.
778-475-5611

[robert holliday]

I have had very good luck with lstechnologies.ca
They had me label the spring as "door closer" and they sent my old spring plus a new one exactly like it only Brand New! Very nice people.
bob holliday
Wichita Ks

[John Usher]

Thank you all for your suggestions.
I’m pursuing all leads…
Best Regards,
John U.

[Chip Bearden]

It's been 30+ years but I heard a story about a pilot who needed a gas strut for his LS3 landing gear in a hurry for a contest and didn't have one. He had saved a previous strut so he installed it side by side with the one in the glider. Each of the old struts had declined to about to about 50% of the spec and then stabilized, so the two together provided the right force. It was a little tight getting them installed but he bought longer bolts for the end fittings and it worked. No interference anywhere in the full range of motion. Everything worked great at a contest in cold weather off a paved runway, with a few field landings tossed in.

At the suggestion of a well-known repair guy, he also removed the damper for this short exercise. Before he added the second spring, he could extend the wheel in the fuselage cradle, then reach up from underneath and feel that the links didn't quite go "over center". The gas spring was too weak and the damper was stiff, especially when the temperature was colder (that combination was the "perfect storm" for an LS self-retracting landing gear event). Removing the damper seemed to fix the "over center" problem itself and the added force from two gas springs helped keep the gear in the right position. No one seemed to knew the purpose of the damper but he surmised that it prevented the landing gear struts from bouncing back and forth during a bumpy landing and potentially allowing the gear to fold up.

I'm not recommending this on a certified glider, just relating a story. ;)

Chip Bearden
JB