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LEGO Technic 9398 Rock Crawler Review



There has been plenty of speculation regarding this now-discontinued set from Lego, first released in 2012. Its official name is the Lego Rock Climber, and contains 1327 pieces in total.


The box is very huge, and utilizes the front flap to show off the functions, much like the ones found in brand new flagship builds.


Meanwhile, the back of the box shows off the alternate model you can build. Keep in mind that the alternate uses the same type of chassis here – The only difference lies in the body. Instructions made for the B model are already taken down from the Lego site, which is unfortunate.


The inside portion of the flap showcases all of the Lego Power Function’s parts, as well as a short demonstration on how these functions work.


Let us now take a look at the instructions – The 9398’s A-model instructions come in three parts. You might guess that the first two parts are all about the build’s chassis while the last one focuses more on the body, since they are built separately – Well, your guess is almost as good as ours. The truth is, there’ only one page of chassis located in the third book.


We’re also pretty convinced that these were only divided up so that each instruction gets an even description of the parts, therefore the booklet breaks aren’t found inside any convenient point. An instruction addendum sheet is also found inside the box, which showcases four types of amended pages. We have to mention here that none of the changes found here were made thanks to a printing error from Lego or something similar – They were all made to clear up the instructions, in case someone does them incorrectly.


A full-page sticker sheet has also been included in the build. We’re really hoping that the quality found in these white stickers will have greatly improved by now, and don’t suffer the same fate as the previously-released Williams Racer build. The initial page of the instructions will reveal that this model was only made for outdoor usage. To be honest, this isn’t really surprising since the unsealed gears fit straight away with the grit found outside.


The Lego 9398 comes with brand new parts. First off, the IR receiver has already changed in a different way – Allowing you to see the V2 found on the front side of the receiver. Next is the brand new servo motor. This thing does contain plenty of attachment options. It’s got a lovely orange output that goes on all the way through, so there’s also an output located on the back. We think that the upper portion of the housing contains both the gear and motor reduction, while this part’s lower half contains a position resolver. There aren’t any spur gear stages found between the two segments, so this results in a high reduction. The 9398’s servo has the ability to rotate 90 degrees from the neutral. Neutral is marked with a couple of dots, and the process of putting in the middle is very interesting, to say the least. If you end up hooking it up to a battery box, then it could drive all the way towards one end or the other end, depending on the build’s own polarity. But if you are able to connect it along with the IR receiver, then it follows complete neutral automatically, as long as there’s no signal involved. So in short, the battery box’s own polarity doesn’t matter one bit. Even though this model contains a one remote that could only ask the servo to go either neutral or full travel, it’s still capable of doing proportional control. For instance, if you attach it to the Li-Po battery box, you can move it around in seven increments in every direction possible. Much to our disappointment, Lego has not even bothered to release a proportional remote. The train remote technically works, but it’s still incapable of handling IR/C-type vehicles like this one.


This is the 9398’s long-awaited L motor. A good advantage here is that it’s much better supported when you attach pins to the vehicle’s sides. It does look the internal motor itself is quite big – But most likely has the same two-stage planetary reduction found in other Lego Technic builds. It may seem like the internal motor itself has a huge size, but most likely only has the same two-stage planetary reduction. The vehicle’s output speed is pretty much the same as the ones found in M-motors. There are also new parts thrown in, such as the black tie rod (although this has shown up in Lego’s other builds). And what’s really interesting here is that the other included parts have not been seen since 1988! The main difference here lies in the color, as well as the fact that these tie rods don’t even contain stops on the inside, allowing you to place in ball joints on either side of the vehicle. This makes it pretty much the only choice you have regarding certain applications. Interestingly enough, this model doesn’t even place in the ball joints in both of its sides, so this part is actually deemed unnecessary – Although a welcome addition, nonetheless. The new tan 4L axle might seem as if it doesn’t hold any useful properties and could be easily thrown away – While the final angled axle connector has its own fair share of uses as well. It really seems like the makers of Lego Technic have borrowed a few elements from past Batman builds.


The parts that come with the Lego 9398 are labelled as 1 and 2. 1 represents the chassis, while 2 is for the body. It’s actually quite obvious that Lego has listened to the requests of its fans, since there are loads of black and orange beams and panels found in this build, as well as four types of portal axle hubs.


Remember when certain Lego Technic fans didn’t really like the idea of grey-colored wheels on the 8110 and instead wished that they were painted black instead, but couldn’t do so since they were hard to get? Well they’re in luck, since the 9398 comes with those black wheels that they wanted so badly. And remember when everyone kept asking Lego to create black smooth toggle connectors for the vehicle? Well, Lego made those too – There’s four of them included inside this build. And we must not forget to mention the brand new motors. An L-motor has always been requested by Lego Technic fans ever since the Power Functions first came out. The main gap in between the XL and the M was quite obvious – Another thing that has been vehemently requested by fans everywhere is the servo motor, and it finally makes an appearance in this build. This is sure to please a lot of fans, although some of us might be happier after we have acquired the right kind of transmitter for it.


The initial part used in the assembly is the vehicle’s servo motor. The motor isn’t just connected to the structure – It’s actually an integral part of the structure itself. The ball joints located on both the front and backside of it let the steering commands to pass both back and forward through the u-joints in the vehicle’s rear and front suspension, minus the help of the steering axle to support the vehicle’s weight. The mere fact that just one motor is utilized for both the rear and front steering means that they are always in sync, since they are connected to one another. Next is the chassis that gets formed around the motor. The diagonal members here are actually a good way to keep the chassis sturdy by making a truss.


Contrary to the Unimog which utilizes two 16-tooth gears found in the portal axle, the Lego 9398 utilizes the 20-tooth and 12-tooth double bevel gears to throw in a bit of mechanical advantage right inside the hub. The black fitting found on top of the wheel spindle is actually present to keep the 3L’s support of the black gear, preventing it from being pushed out while you fix the hub to the suspension assembly. We could always use more of these things in future Lego Technic builds. Technically these parts are repetitive after you have constructed them, just so you could take them out whenever you want – Even though they could help prevent it from falling out under the load.


We have had a couple of observations here regarding the front suspension assembly, which is connected to the second chassis:

  • The drive is passed through the steering to the hub, with the help of ujoints. Unlike the CV joints, this means that the wheel doesn’t rotate at a fixed speed whenever it gets turned. But the steering lock is so tiny that it’s not really that noticeable.
  • Unlike the Unimog, the steering hubs will use these pins to make the vehicle easier to move around.
  • Meanwhile, the steering rack is connected to the tubs with the help of friction pins. The main purpose of this is to remove the slop in the steering – And it works just fine.

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