Trial Crawler

Trial Crawler, features drive, steering, winch, suspensions, gearbox, fake engine and orange color !


Direct purchase of the instructions

Trial Crawler
10,00  -Excl. Tax
A LEGO Technic remote controlled Trial Crawler, features 4x4 drive with fake engine, steering, optional winch with gearbox and suspensions. In a crawler buggy design.

Preview of the instructions at the end of the article. Presentation Video (YouTube).

Regarding my previous Trial Vehicle, all were trucks, that is why I wanted to build a new trial vehicle with new design : a crawler. For that purpose, I wanted to use the Unimog Parts sold by Lego, notably : ball-joins, shock absorbers, panels and frame. The drive is operated by a XL motor with 12/20 and 8/24 reinforced portal hub wheels. The steering motor is located on the left side of the crawler and operates 2 cv-joins, 12/clutch and 8/24 which ensures a good reactivity and strength on the steering. Concerning the chassis, it is composed of two levels of beam which encircle the XL motor, gearbox and the battery box. The axle are live axles with 5 points : the massive ball-join, the two connecting rods, and the two shock absorbers attached to the upper level of the frame.


The crawler is also equipped with a winch located under the bonnet and a gearbox. The gearbox controlled the two outputs of the motor, either the drive, or the winch. The driving ring is simply operated by the red change over-catch located near the dashboard. This principle of functioning allows the wheels to rotate when the winch works. I have tried to link the winch with the wheels but the results were really problematic due to the slipping of the wheels on mud slopes. With this solution, I can operate the winch only or the drive only which is reassuring for the two devices.


Also, in order to have a nice design, I have considered different places for the engine and the best was on the rear with a big detailed engine. For that, I used chromed bricks bought at Chrome Block City and lot of special part like the gray panel or tailpipe bricks. Concerning the result : it is exactly what I wanted, looks good and big with a powerful impression. To continue with the design process, I have also considered lot of solutions to design the global shape. I wanted to use the orange panel, but they are in low quantity in the unimog. That is why I have chosen the black color for the frame in order to match with the orange color. In order to stay in crawler design, I have made a tube-shaped design which has the advantages to be light and easily removable. To conclude with the climbing abilities : video says more than thousand words.

Building Instructions


I have created firstly a dismantling sequence. I wanted after some years to offer a better looking instructions with modernized parts usage, Here it is, thanks to ForelockMocs who have made a great job making a professional instructions. The building instructions are a PDF of 127  pages step by step computer rendering building instructions in a same way Lego do. The bill of material is available here :

Want to know if you can build the Trial Crawler (enhanced edition) ? It has been indexed to rebrickable, check it !

You can buy the building instructions for 10€. You can also buy other building instructions and get an automated discount. You will get 15% off for 2 PDF, and 20% off for 3 PDF on the total), available for all the instructions for sale on

See it on the shop :

Trial Crawler
10,00  -Excl. Tax
A LEGO Technic remote controlled Trial Crawler, features 4x4 drive with fake engine, steering, optional winch with gearbox and suspensions. In a crawler buggy design.

After your payment, you will be redirected to a page for downloading your instructions, and will receive also the link to download by email. Please check the spam box and be patient to receive it. If you have trouble to download your copy of the PDF after payment or open the document, do not make a paypal dispute, please contact me using the contact form. The link to download the instructions expires within 24h. Contact me if you have lost your instructions. Note that you can print it, but not copy or distribute. Thank you for supporting my work 🙂

Here is some preview of the building instructions :

Free Photo Sequence

This is a photo sequence of dismantling in reverse order that I have taken initially, some parts usage are a bit outdated. You can download the PDF and see the bill of material in the following links :

Downloading the high definition PDF building instructions. Trial Crawler by Nico71 – 15mo, PDF

  Want to check before if you can build the Trial Crawler ? The Trial Crawler has been indexed to

(27) Comments

    It would be cool if you could make something simular to this but a little bit faster and more ”Axial Wraith” like. So a bit more lightweight and a bit more faster, or just use RC buggy motors.

    Hi, I want to make this set till I saw the XL gear rack. Do I need the gear rack or can I use the small gear rack? If I need the gear rack what set is it in? Thanks.


    Hi, I was looking at this and I wanted to build it but I had 1 question do you need that gear rack or can you substitute? if so what set is in?


    @LT64 So why is it necessary to use cv joints? Couldn’t I just replace them with 3L u-joints, or would that cause problems? Plus, I already broke a few of them with high torque, and I can’t get more, because I’m a kid, and I’m not allowed to order stuff online.

    Merci Beaucoup c’est résolu ^^ Mais maintenant même avec les piles chargés a fond le crawler ne grimpe rien … Il se bloque au moindre obstacle, a la moindre montée…

    I have a quick question: Is it really necessary to have CV joints on the steering shaft? I really want to build this crawler, and I just got 9398, but that doesn’t have any CV joints.

    Il te faut juste inverser la position de la roue dentée de 20 dents sur l’essieu arrière ou avant. Regarde bien la notice, tu as du te tromper. Si elle est à gauche, passe là à droite, et inversement 🙂

    Hi Nico71 ! I’m not very good in english, so i will expose you my problem in french :

    J’ai construit ton MOC qui a été un plaisir a “builder”, mais en le testant, j’ai remarquer que les deux essieux ne tournent pas dans le même sens… Je ne vois pas d’où cela vient, tu as une idée ?

    Thanks so much if you reply 🙂

    We Built your crawler, but we might have done something wrong in the building, because the CV joints kept falling apart and when we replaced them with 4L universal joints, the axles keep falling out from the 12 tooth gear or the motor. We also have problems with the gearbox and the axle on the back side of the gearbox jumps out and locks the battery box when it rolls over. Do you know how we could fix it.


    Hey, I’m a big fan of your creations and how you are able to integrate such working components. This crawler is no exception to the complex mechanics. I like how you applied the new technic bricks into your model, props! I hope you make more trial trucks soon! I will be looking forward to seeing what else you come up with. Cheers…

    Hey, where do you the wheels or did you color them ?
    And what are the pices in the instructions without a picture ? Answer please!!

    Thanks for the instructions I made a copy and worked great, I had to make my axels using the portals from 8110 as I did not have enough parts for your design.

    Why no Differentials?

    must have a lot of tyre squeal on the kitchen floor – off road its ok I guess…

    Hi Nico,
    This is a very interesting crawler that you did here.
    I am new to lego, just bought myself a 8110 Unimog last month.

    I am really interested in building this crawler. Can you give me a rough estimation how much will all of the parts cost if I were to purchase them from Bricklink?

    Thank you.

    Bonjour, voulais vous demander si il ya encore beaucoup pour les déclarations faites?
    Et aussi voulu savoir si la plupart des pièces viennent avec conjuto 8110?

    I don’t think so. If you have not the special part, you can build the unimog V4 but without the massive ball-join, I don’t think it is possible to rebuilt one with classic parts. Regards

    Hi Nico,

    You did a great job again! Excellent modell, well done! 🙂
    I have a question: Do you think is it possible to build it without the special unimog parts? Thank you.

    Kind regards,

Comments are closed.