Which techmaxs are you talking about? There are three different kinds being discussed here on the forums and many times nobody distinguishes between them. The Techmax Small Design fit no problem. The Techmax Gen 1/2/minis require modifying the housings if you have the USDM style housing.
I ordered all three kinds and I can say with certainty that only the small design will fit without modifying the housing if you have the USDM style housing. They go in quickly and easily, just like a standard H11.
I actually managed to get the gen1/gen2/mini into the socket but there was so much pressure from the housing clearing issue that i couldn't rotate them at all. The housing contacted the fan assembly and pressed the whole bulb assembly into the socket hole with a lot of pressure. The fan wouldn't spin because of the pressure.
And to be clear, the dust cap isn't the issue. The housing itself is too short to allow the length of the techmax's to work. The fan assembly collides with the housing and doesn't allow the bulbs to be inserted. Unless you've found some insertion method that works, in which case please show us how that's done. You replied to a comment that had photos showing the issue so you're aware of what I'm talking about.
https://www.fiestastforum.com/threa...b-info-finds-and-discussion.18114/post-457659
Small design -
https://www.amazon.com/dp/B07WNVVSNK
Gen 2 -
https://www.amazon.com/dp/B07RJN9SPV
Mini -
https://www.amazon.com/dp/B07C1LTQ92