Hinge joints FIXED

Hi, I’m trying to make a model of a futuristic “bigfoot car” working physically.

My problem is that the hinge joints are not really “hard” enough.
They bend on their axis and I can’t find any options to keep them in their place.
I noticed this also before but I didn’t need a perfect alignment like I need now.

Example of what happens in this webplayer (less than 300Kb).

All the hinges (there are many there) look like they don’t only rotate on the hinge axis but also on the other axis and I really can’t find an option to fix this.
You can see that the front wheels “open up” while they should stay perpendicular to the ground, or if you prefer, keeping their axis parallel to the ground.
Should I code this manually to keep them aligned?

Thank you for your help!

I updated the webplayer, you can now “drive” the car with W and S, forward and backward and cam is now inside the car so you can easily see what I mean.
The 2 arms that hold the wheels are trembling in all axes, whihle they should only rotate on one axis.

Nobody knows the solution to this?
Tried the freeze rotation and position but it looks like they are not relative to the parent but to the world, so that is not what I want… if only it was frozen relative to parent that would have been perfect.
I also tried to put less weight on the objects, one wheel in example is 600 kg and I tried to put all at 1/10 of the weight, but nothing changed.

It sounds strange to me that all these connections are so loose… it means not even a barrow can be built and I don’t think it’s the case…

Thanks everybody for no help :roll_eyes: