Good morning - hope it's been (financial markets notwithstanding) a decent week for everyone.

I recently bought a set of AA's rebuilt Boge front struts replacing the worn out ones in the '75. I got the old ones out but the replacement Boge ones don't fit the same way. More specifically with the ones I removed the threaded Hexagon-head bolt (914 341 804 00 with red arrow) threaded all the way down whereas the with the supplied Boge one it will only thread about 1/2 way down.

Everything is clean and aligned and the strut is fully seated in the tube.

Is it normal/OK for that not to full thread all the way down or is 1/2 the threads engaged OK?

Thanks!

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Oh those darn caps.

Technically you should use the cap provided with the new strut insert. But I've noticed the same thing . . . sometimes they don't fit the way I'd prefer.

Sometimes you can reuse the old cap if the top of the stut formation is exactly the same as the take out part.

However, the catch is that it must fit and capture the top of the strut properly so you don't get wobbling and/or so you're not crusing the top of the strut and damaging the seal.

Without some careful checking of the fit, I've seen a case where the old cap was just pushing the top of the strut. When the cap was tight you couldn't move the strut by hand but in the car it "wobbled" creating a click/clunk. This was a long time ago on my original teener. I pulled it all apart, used the new cap, problem solved. And yes . . . the new cap didn't bottom all the way. My recollection though was it was only a couple threads not 1/2.

Check fit carefully, make sure you have the right cap. Also make sure there isn't "junk" on the bottom of the strut insert holding the insert up higher than it should be.

Another thought is check the strut body and make sure the internal threads are rusted & goobered up keeping a new (potentially longer) threaded cap from runing down the threads all the way.

Good morning.

Sorry for not being clear, I was using the new caps provided by AA. I should’ve also added that they will thread all the way home without the strut in there, it just feels like at some point they bought them out, I think the Strutt is located securely, I just haven’t had this happen before but then again I haven’t installed Boge struts before either.

Never seen a cap that screwed all the way down on Koni, Boge, Bilstein. Usually one to three rings showing has been my observation.

Thanks Mark - appreciate the confirmation. Oddly the Koni's I've installed have fully seated.

I'll get these replacement Boge one's fitted and go from there - thanks!

I called Bilstein. They want 2-3mm of exposed threads so you know it’s tight without being bottomed out.

Wow Mark - thank you for doing that. Very much appreciated.

Just to be clear - the parts I received from AA are fitting properly based on this. I had to clean a couple threads up but once done figment was correct.

I had called them a couple years ago when I was installing Bils into my Boge struts. Talked to a tech guy and he confirmed a couple threads should show and they no longer take an ounce or two of oil in the strut housing. No bump stop on the bils because unlike Boge, they have an internal bump stop.

So I got these in with a small amount of oil in the tube and about 1/2 the threads seated. The amount of thread engaged/exposed was identical per side.

These have a nice ride quality.

Follow up question - something that Mark said triggered a question: Did the different struts have different bump stop heights?

In other words will a Koni have a different bump stop shape/dimensions than a Boge etc?

The Manual only lists the one for Boge
901 343 301 00

Thanks Steve, just checked the parts manual as well and I only the one listing you referenced. So one size fit all then?

yes, if you have it, use the old cap, the new one is of a different manufacture, and although will not tread all of the way down because of the cap design, is safe to use

The manual doesn't specify, but that it's needed for both Boge and Koni. Bilstein has a built in stop.

Also, from experience, add a drop of locktite to the threads on the cap. I have seen them back off and then the strut cartridge starts to flop around in the strut.

Clay

Thanks for all of the responses and education. Good tip Clay.