Andro

Lego replied to my mail today. They didn't said anything specific on the topic. They said "sorry" and "we are sending you new gears". Right now the model is working great with some washers here ant there, some black gears in specific places and lubricated.

Sorry to hear that. It wasn't an easy decision for me to cut it but now it works like charm (with a washer on the side of the beam). Now that I definitely know that these gears are problematic maybe I won't think twice to cut another one if needed. Another idea is to reshape one a little bit on the lathe. :)

I'm not going to disassemble the model right now to reach those gears but I experimented a little bit with other 20t gears. All tans grind the same way, black ones are so-so and the grey ones are almost perfect. I contacted Lego and am waiting for a response on this one. I'll keep you posted.

Thanks guys for the idea. I will try to get replacements too. Though it's kind of fun to use washers in LEGO. Makes it more real. :)

Hi there I started building my 42070 6x6 Tow Truck A Model. This time I wanted to try to lubricate all the moving parts and pay more attention to the friction. It's a slower process but axles and gears move apparently better. My concern is with DOUBLE CONICAL WHEEL Z20 1M (https://brickset.com/parts/design-32269). Its teeth are touching the beam to which it is mounted and there is a lot of friction there and noise. So I decided to add a flat washer and it makes a big difference. First I made a washer out of thin plastic to test the idea and then I just bought thin (0.1 mm) washers to work with. The other problem with those gears is that in this part of the gear box they are too close to each other and they are teeth are touching each other. The gear is added on page 38 in the instruction. I tried it without the washers or with more washers on different sides and the problem stays. If I don't put washers and press the gears to the beams firmly they don't touch each other but they touch the beams. At the end after a lot of thoughts I sacrificed one of them and cut the teeth a little bit. You can see it in the second picture. I have never done such things before and it was a very tough decision. So now its working without awful noises. So what do you think of all that?

I'm Andrey from Bulgaria. I'm fan of Technic but together with the kids I have fun playing with any LEGO - from Duplo to Ninjago. I'm also a self-taught woodworker and a software engineer. I joined the forum to discuss some Technic ideas with someone because I don't have enough friends that still play with LEGO.