Andman

@AlessandroB, @BrickTronic, sorry for my late replay. Here are some pics, which should help you. If not, drop a message. When you are done. Just re-assemble. before you close the case make sure everything works as expected.

The forced firmware update is just a shot in the dark. Here is how you do that. If that doesn't help, I would contact Lego.

So this happens, when you want to lower or raise the dumper body? Looks more like a software issue or a motor internal issue. Shouldn't be a mistake during building, because the gear switcher is directly connected to the motor. Did you try a forced firmware update on your lego technic hub? I doubt, that it'll work, but inure could try to reinstall the Control+ App, too.

@VermontDave, I can confirm that the purple pieces is blocke by that beam. So, it cannot moved clockwise from 3 o'clock to 6 o'clock. It has to go counterclockwise to reach 6 o'clock. That way the motor can detect it's position. Could you post a video? You could use Flickr, Bricksafe to Youtube.

@Jgooffer, I'm sorry. I don't know what else i can do. The only advice i can give and what already suggested by others, is that you start over again and pay close attention to the instructions. Good luck!

Posting pictures and videos helps a lot to troubleshoot the issues. Please use for example bricksafe.com or flickr.com and embed the images and videos here. What switches back? The purple part in the gearbox? When you are looking from behind at the dumper, can you confirm the following positions of the purple part? 3 o'clock - 1st gear 12 o'clock - 2nd gear 9 o'clock - 3rd gear 6 o'clock - lowering and raising the dumper body When I raise or lower the dumper body at my volvo and then stop at any position, the purple part goes back from 6 o'clock to 3 o'clock when the automatic gearbox is activated.

Seriously... You aren't following carefully the instructions. On page 31 it shows how the gearbox elements should be placed. This is what you have build: So please compare the image on the right side of pages 31 and the picture above in my post. Do you see any differences? You are answer should be yes, because I see one. So... please follow the instructions carefully. Pay attention on how parts placed. Also pay attention on how parts are placed relatively to each other. This is crucial. I'm sorry to say that, but if you don't do that; if you don't pay attention, I'm wasting my time helping you. If you don't see it click on the spoiler

Welcome to the forum! For this kind of stuff, this is the correct forum. All you questions can basically answered with yes. But i think many people here are buying/collection Lego (Technic) since many years. At least did and still do. As time passes... lets say the part count magically never goes down :-) If you are interested in sets, which give you a good start, search the forum for "parts pack". There are certain sets, which give you a better variety and more parts for a reasonable price.

Please please don't apologize. There is nothing like an expected level of posts here. There are no stupid questions. Only stupid answers. And it is smarter to ask, then not to. Glad you found the mistake. Just reach out again, if you encounter any other issues. I'm sure there are some people willing to help you, including me. You might find this thread helpful, too. It covers some issues, other people encountered. @lostinroy, based on the position of the driving rings, it is intended that some gears are blocked.

I assume he confirmed it here. He didn't update/add any new pictures.

Patience, my friend :-) @Jgooffer, Look at the image below I would say you are missing the parts installed at step 99 on page 60. Please check that first before posting images or videos. I would like to repeat what @TeamThrifty mentioned before. The Set is not flawed. You just have to carefully follow the instructions.

Then they are missing in the set. Just contact Lego here: https://www.lego.com/en-us/service/replacementparts

It still looks like you are missing the axle installed in step 66. This axle is not visible in your latest video and in your latest pictures. This axle drives the central diff, which drives all axles. Please check again.

Are you expecting the rear axle to turn? This will not happen because the axle which drives the central diff between the gearbox and the motors is not installed. @benovitch, sorry didn't see your post. Should have updated the page before sending my post. Thanks for the detailed help. Maybe the following image helps too.

Can't see the videos. EDIT: I just went to your flickr account directly and was able to see the video. The first thing I noticed is that when you switched the orange part it just switched the position of the upper and lower driving ring. Not the one in the middle behind the orange part. I'll try to create some digital CAD pictures to provide a better understanding of the gearbox.

Exactly. At least from what i understood :-D

@TeamThrifty, is right. Just look at the back of the Volvo. I had a look at your image. Seems to be ok.

Could you make the image publicly available? I don't have an account there and don't have the permission view it. The strange white thing is a clutch. This path of the gearbox is engaged when you lower or raise the dumper body. This prevents the Volvo from rolling away. So if you have a look from behind the purple cable holder can have the following positions: 03:00 - 1st gear 12:00 - 2nd gear 09:00 - 3rd gear 06:00 - drivetrain blocked (when lowering/raising the dumper body)

My contribution? Scroll up! Balance wont help the OP here ;-) Yes and no. I still experience issues with steering. Sometimes it just starts to steer left and right rapidly. But that's not related to the gearbox of course. As for the gearbox, i fully agree. You need to be careful.

OP obviously is experiencing issues. Weather due to hardware or software issues doesn't matter. That's why he is seeking for help. Great that you made it the first time. But your post is not helpful at all and superfluous.

When you are turning the front axle, in which direction are the rear axles spinning? They should spin in the opposite direction? Min worked just fine, when i used it the last time. I can try it out again, just to exclude a possible general issue with the app. @Jgooffer, please double check this step: https://www.lego.com/cdn/product-assets/product.bi.core.pdf/6332383.pdf#page=31 Please have a very close look at the positioning of the purple cable holder and the driving rings 3l The upper driving ring has to be aligned to the right, the one in the middle has to be positioned in the middle and the bottom ring has to be on the right side while the puprle cable holder has to point upwards. When the first gear is engaged the cable holder points to you. In that case the upper and the lower driving ring are in the middle position on the axle. The middle driving ring is pushed to the right. When you are raising and lowering the dumper body the drive train is blocked by a clutch. That's waht you see/install at steps 46 to 48.

Hers is a list of all models which contained that type of wheel: https://www.bricklink.com/catalogItemIn.asp?P=2696&in=S There was nothing like that listed. It's very likely a custom build.

From what I can see, they will.

@tvdv, the rebuild of a model is the equivalent to "Did you try to turn it off and on again" in the IT. Glad it worked out!

The Charger already uses hard springs. I'm not an expert when it comes to suspension, but I would guess you only get a harder suspensions by adding more springs or redesign the whole suspension.