Looking for Filter Cap Thread Specs

[Iconically_Lost]

Hi All, I am trying to find the exact specs on a buttress threads used on a BMW oil filter cap. I have tried to search around and blindly guessing and have gotten "somewhat" close-ish but what feels like no cigar. I am looking to make my own filter cap out of aluminium, as a personal pet project. Not for re-sale.

I've beet testing the thread specs with a 3d printer, have gotten something that will screw onto the cap and looks like it marries up to the OE threads. I unfortunately don't have access to the thread that the caps screws into, so I can't test how close am I.

Whilst the end game is to have this made out of aluminium, and have a machine shop that agreed to do it. They are too costly to measure/figure out the current specs., and others don't want to mess with this.

Hence the question, if anyone know what the actual specs BMW used. Would be highly appreciated.


The 3D print was done with the dimensions of the top sketch in .12mm.

 

[Kira]

It's impressive that you were able to replicate the male threads...congrats...tip of the cap.
Can you get a look at the tap used to cut the female treads?

"Too costly" and too time consuming might take the day here.

 

[eljefino]

You may find a market (here) for your invention, keep up the good work!

I've found a Castrol quart bottle nearly threads into my Toyota fill holes. I cut one in half to use as a funnel, but have also left old bottles screwed in to trickle-drain over the spans of many minutes.

 

[JohnnyJohnson]

LOL well you could always buy what the $200 OEM replacement.

 

[ZeeOSix]

Looks like you've figured out the thread pitch at being 3.0 mm. So measure the inside and outside diameters of the threads and you'd have it.

 

[Iconically_Lost]

LOL well you could always buy what the $200 OEM replacement.

Actually they are like $60.

It's impressive that you were able to replicate the male threads...congrats...tip of the cap.
Can you get a look at the tap used to cut the female treads?

"Too costly" and too time consuming might take the day here.

I feel like there should be more thread engagement, hence asking if any one knows what dimensions BMW uses.

 

[JohnnyJohnson]

Actually they are like $60.


I feel like there should be more thread engagement, hence asking if any one knows what dimensions BMW uses.

This is why I will never buy a BMW or a MB..