Strut housing gland nut question

[Andy Goldberg]

I bought a pair of used "S" type strut housings with the plan to fit them to my '74 911 Coupe. They are Koni housings stamped "911 341 080 16" and "911 341 079 16" My problem is that I cannot find 'gland nuts' that fit correctly. This pair of used housings came with one old 'insert' and one gland nut. When I tried to find new inserts for them, I discovered that Koni no longer makes inserts for older "S" housings. I was able to track down a pair of "new old stock" inserts, however they came only with gland nuts that do not fit into these into these housings.

In my photos, you can see that the 'old' insert is shorter than the new one and that the old gland nut is 'longer' to make up the difference. However, the 'new' gland nuts have a smaller diameter and larger thread pitch than the 'old' nut and don't fit the treads inside the top of the housings.

I came across a photo on this fourm of early 911 strut housings that seem to have the same gland nut that came with the my used housings.
(That's the last photo.)

Can anyone identify these used housings, the 'shorter' old insert or the 'Longer, wider gland nut with the 'finer threads?'

Many thanks in advance,
Andy

[gled49]

If the threads in your struts aren’t fine like the gland nuts you have, then the struts aren’t Koni. Probably Boge. G

[1968DT]

Try Paragon , I had a similar issue with Koni gland nuts.

https://www.paragon-products.com

Good Luck

[Phil Planck]

I called Koni usa tech line. Very helpful. They may be able to supply proper gland nut.

[Andy Goldberg]

OK, I think I have figured out what is going on. These are a rare and weird variation of a Koni strut, known as 'wet struts.' The strut "main housing' is larger than other Koni housings. This is to allow for hydraulic oil which has to be poured into the 'main housing.' The insert is a cylinder and piston arrangement that is immersed into the oil filled 'main housing' of the strut. The gland nut is 'oversized' to fit the wider 'main housing' and has a scraper seal to keep the oil within the 'main housing.' To make things even more complicated, there is more than one type of 'insert' that can be used with these 'main housings.' Some have their own sealed outer tube and contain oil, and have the gland nut attached.
I am going to try to sell on these 'rare and strange' struts in the hope that someone is restoring an old 911 that came from the factory with this type of strut. I'm headed over to Elephant Racing tomorrow to choose a 'modern' strut and insert for use in my 911.
I'll have to decide between buying a custom RSR strut, with aggressive valving and raised spindle, or a Bilstein 'Sport' housing with 'off the shelf' Bilstein inserts.
Thanks to everyone who offered suggestions on how to solve my strut issues.

[Andy Goldberg]

If the threads in your struts aren’t fine like the gland nuts you have, then the struts aren’t Koni. Probably Boge. G

The housings have 'fine thread' and they are stamped 'Koni'. It turns out that they are a 'rare and strange' strut know as a 'wet strut' These were used on some early 911 cars. Especially the short wheel base versions.

[gled49]

Not weird or rare, all early struts were built that way, I have installed many front strut shocks. You remove the open shock insert and all the parts including the foot valves that have come off from lowering the car too much, suck out the oil and re-install a new sealed insert.

[Andy Goldberg]

I have been 'in touch' with Koni USA, it looks like they will have some of the 'older' gland nuts available for me in 2 weeks. This has been a 'crash course' in the various versions of the strut Koni has made for 911's of the sixties and seventies. I am wondering if they have a 'gland nut' that has the correct diameter and thread pitch for the 'open' type strut, but are the correct 'length' for modern 'closed' inserts. Do you know if new inserts can be used with 'open' type strut 'main housings?'

[Andy Goldberg]

I called Koni usa tech line. Very helpful. They may be able to supply proper gland nut.

I've been communicating with them, so far they are have been very helpful indeed! Looks like they are currently 'out of stock' on the correct gland nut, but have some coming in soon.

[Andy Goldberg]

HAPPY ENDING! Well, the good folks at Koni (Masson O'Hara) informed me which gland nuts I needed, and put me on to Paragon Products to source them. Jason at Paragon had the nuts in stock and helped me choose Koni 'gas charged' sport inserts for my strut housings to 'match' my 21mm torsion bars. Also, Jason helped me address the 'understeer' issure with my 911 and will be removing my 19mm anti sway bar up front and reinstalling the 16mm bar that came with my car. This should be a better combination with my 18mm rear anti sway bar. Thanks to everyone who posted to this thread, I appreciate your input.
Andy G
San Jose CA
(Home track: Laguan Seca)