LEGO Technic 42110 Land Rover Defender Ultimate repair guide

what’s up guys this is Balazs from Racing Brick I shared many videos with you about the LEGO Technic Land Rover Defender already you saw my building review the details of the drivetrain and one about the cracking noise and the possible fixes I received hundreds of comments from you and many many requests for help hopefully most of the cases I was able to assist to find the proper solution I decided to create this video with the most common problems that you shared with me in the past few months and I will do my best to show the solution to each of them this will be a pretty long one with a visual presentation of the drivetrain then the different segments focusing on each potential problem during the building process, how to verify your build and what are the problems that are not really problems at all I created a detailed blog post on my webpage if you have a specific issue then I suggest to use that one as a starting point for each problem I will link the appropriate section of this video so let’s start with the basic concept I created a video previously that shows how the drive train works but based on the comments received I think it still requires some explanation understanding the whole concept is very important without that it is quite difficult to find the root cause of the different issues here is the 3d model of the defender I will use it to explain the different sections starting from the wheels up until the engine under the hood let’s start with the front wheels as you see the front wheels are driving these axles through the front differential then the speed is significantly reduced through these gears the next one is the rear axle we see a similar differential and a similar gear reduction but this time it is behind the axle these two axles meet in the middle where you can see the central differential the movement from the front and rear axles is joined here in the central differential and then it is transferred through these gears to the DNR selector DNR means drive neutral and reverse here you can see the selector in neutral position this means that no further gears are engaged in this position the car is rolling freely if you push the lever to the reverse position then this driving green will connect to this clutch gear that red clutch gear then drives all these other gears up until the engine what that means is in Reverse the high/low selector and the complete gearbox is bypassed the wheels are driving the engine directly now let’s see what happens in drive position in this case the other clutch gear is engaged through this yellow driving ring extension and we arrive to the high/low selector which is next to the DNR selector it also has three positions although the middle one is not used if you don’t select high or low then again nothing happens the gearbox is not engaged as you see the high and low positions have similar gears but they are swapped so they will either slow down or speed up the transmission after the hi/lo selector here’s the axle that is the input shaft for the gearbox the orientation of the universal joints is very important but more about this later here’s the four-speed gearbox at the rear of the car I will not go into details here there are four gears that are selected with this knob they will make this output shaft slower or faster depending on the gear selected there’s only one step remaining the axle that connects the output shaft coming from the gearbox with the engine again through a series of gears as you can see there are tons of different gears engaged when the car is in Drive so it is no surprise that the drivetrain has so many potential traps and issues it has actually more gears built in than the Bugatti Chiron so this was a quick overview of the operation if you have a problem with a gear stuck somewhere or a function not working at all then I suggest to study the mechanism and start the inspection from the differentials up until the engine to locate your issue the best way to do it is to block three wheels and turn manually only one this way you can see which gears are engaged exactly I suggest to do this on both the front and rear axles it is also advised to strip down the model to this state this way you have a much better view on the gears and the axles otherwise it is quite difficult to identify the problems here’s a quick step-by-step guide about the strip down process first you remove the accessories from the roof then the entire roof rack comes off fairly easily for the doors you need to disconnect this piece at the bottom then slide out the two black pins that hold the upper part after those the door can be removed as only one pin holds it at the bottom let’s do this on both sides the removal of the fenders is easy they are only held in place with a couple of pins now to the hood it is held in place with two hinges you can pull apart the rear of the hood to be able to remove it from the hinges now let’s disconnect the top of the A pillars, then this gray axle below

after this the whole section on the side can be disconnected make sure that fake engine parts stay in place now let’s do the same on the other side as well you also need to disconnect the front section of the car from the lower bumper area if it’s done then the whole front section should come off easily now let’s see the rear of the car the rear door has only two pins to disconnect and it comes off to remove the whole rear section first me to push out this gray pin we’ll need an axle or something similar to do it then use the same axle to push out two brown axles as well with the brown axes pulled out it is easy to remove the rear bumper now let’s turn the car and disconnect these pieces in front of the rear wheels on both sides at this point the whole body is only held in place with those two pins on the two sides if you disconnect them then the body will come off please note that the hand of God steering here will also disconnect on the top of the cabin now we only have the seats remaining for the rear than the front ones the removal of the steering rod is optional so here is the body stripped down and you can see what components were removed now let’s see the building process from the very beginning I will show you the critical steps what are the potential issues what are the symptoms and how can you correct them please note these are not all potential issues I will maintain and update the list on my webpage so please use that one as a reference the first problem is at a very early stage at step 3 here you need to use a dark bluish gray 8 tooth gear but I guess is not properly visible on the instructions and a lot of people uses a black 12 toot hgear instead this becomes a problem at Step 62 as you see with the bigger gear it is not possible to properly push together the two assemblies the gear on top will be forced upwards and the axle will be angled making it nearly impossible to turn to have this corrected you need to remove the bigger black gear and use the correct small 8 tooth dark bluish gray one the next one is at step 4 the orientation of the rear differential as you see here if the gears are on the right of the assembly and the wider part of the differential should be on top if the direction of one differential is swapped then the wheels will work against each other and the central differential won’t work at step 45 you need to pay attention to the correct gear usage and position you need to have the light bluish grey 16 tooth gear and the dark bluish gray 8 too th gear on the bottom axle when you add the 24 tooth gear there’s a black piece behind it and then it slides on the axle and connects to the small 8 tooth gear this one is a very common mistake at step 65 as you see the axle coming from the differential rotates freely this dark bluish gray pin-axle cross block needs to slide on the tan axle but you need to pay attention because the part with the hole goes on the axle and not the other one so what happens if you make the mistake in this case axle coming from the differential will be blocked and the small axle holding the piece in place probably slides out the blocked axle means that you won’t be able to move both rear wheels forward together they will be totally blocked to have this corrected you need to remove that cross block and insert it in a proper way at step 84 there’s a dark bluish gray cross block again and if you put it

on the red axle incorrectly then it will block the yellow axle you put through it at the next step that axle is the output of the center of differential that means practically all your wheels will be blocked if you turn them together in one direction so when you try to push your car forward so this is the correct orientation as you see the yellow axle supposed to turn freely at step 88 and 89 you add the input and output axles of the gearbox with four u-joints their orientation is very important as a wrong assembly can be the major cause of the sluggish drivetrain and the cracking noise the first version of the printed and online manuals showed the wrong assembly at step 89 but that was later corrected and the new sets come with an updated printed manual and the online version was changed as well you need to make sure that on the axle both U joints have the same orientation the notches on them should face the same direction I linked above my detailed video about this issue you can have a look at it at Step 102 it is easy to miss the instruction to push the short red axle in if you miss that step then the whole assembly will be loose and the gears won’t be pushed against each other properly so you might have some cracking at step 104 and 106 you need to make sure that the lower attachment point of the springs is the outer axle hole of the suspension arm and not the inner one the inner one is a simple hole so the brown axle won’t be held there firmly and the bigger problem is that the whole suspension will have less stiffness so the rear of the car will sit down after bag 1 we start to build the front differential at step 134 you need to pay attention again to the correct orientation since the piece is symmetrical you need to make sure that you assemble it correctly with the other parts at step 136 as it is highlighted in the instructions at step 152 and 154 you need to pay attention to the lower attachment points of the springs over the front axle the correct attachment point on the suspension arm is the outer one with the axle hole if you put the brown axle in the inner hole then the suspension will look soft and the front of the car will be lower than the rear steps 259 to 261 are critical steps this is the assembly of the DNR and Hi/Lo selectors there are a lot of things you need to pay attention to the rear part of the bottom section moves forward and backward and there’s also moving cross block at the front you need to make sure that the two red levers are properly aligned with the driving rings below otherwise they won’t work it is not very easy to make it right now you need to push in the gray axle at the back to fix that part that was moving back and forth after these the two brown axles should be also pushed all the way in and the blue pins as well when you push together the two parts make sure that the axles goes in the proper holes at step 271 make sure you don’t forget to add the small 8 tooth gear before pushing the black axle in place otherwise there won’t be any connection between the front wheels and the central differential at step 272 you need to connect the input and output shafts of the gearbox you don’t need to push them all the way in there can be a little gap you need to make sure that the inner U joint does not touch the 24 tooth gear otherwise it will also affect the whole drivetrain and can be a source of the cracking noise now let’s see the verification steps I suggest to do the first verification at

step 123 before starting bag 2 – at this point you already have the rear section built with rear axle and the gearbox this axle is for the hand of God steering, it needs to rotate freely about the wheels it is perfectly normal if you turn the wheel on one side and the other turns in the other direction this is how differentials work they both should turn in the same direction if the output axle is turned you can test it with the gears at the rear the yellow axles at the front both should rotate freely they are connected to the central differential if you block one of them then you should be able to drive the wheels through the rear differential both wheels should turn in the same direction here we have the input and output shafts of the gearbox and you can switch between the gears with the black piece on top you can verify the different gears by turning the input axle and checking the rotation speed of the output axle there will be some resistance in the higher gears but you should be able to turn it without any blocking at step 321 all working functions are built so you can put on the wheels and test everything the car should be able to smoothly without any cracking noise the steering wheel and the winch should be working as well the best way to test the drivetrain is to leave three wheels on the ground and lift only one and rotate it manually, in R and D the gearbox and the engine should be engaged if you switch to neutral then the gears in the gearbox and the engine should not work when you switch to reverse the engine should start almost instantly despite the direct drive of the engine from the DNR selector sooner or later the gears in the gearbox will also start to rotate but that’s normal in this case the gearbox is driven by the engine backwards but it does not affect the speed of the engine, in drive you should be able to see the speed of the engine changing as you switch gears and also the effect of the high-low selector shall be visible it is important to verify the orientation of the differentials the car’s front is at the left now and as you see both differentials have their wide parts upwards this is really important if any of them is facing the wrong direction then you will have problems so what is not a problem here if you turn one wheel manually then the wheel on the same axle on the other side will start to turn in the other direction this is perfectly normal this is how differentials work if you rotate manually the shaft coming from the front axle then the rear wheels will rotate against the front ones that’s again perfectly normal this is because of the central differential if you rotate manually the central differential then all wheels should turn in the same direction if the central differential has some resistance when you rotate it manually then check the gear you are in in higher gears it will be quite a challenge if you switch to a lower gear then it should be fairly easy to rotate it now let’s see what happens if one of the differentials is facing the wrong direction as you see here I rotated the front differential the problem becomes visible when I rotate the central differential manually

in this case the wheels all supposed to turn in the same direction normally but here they are turning in the opposite direction this means if I push the car on the ground the front and rear axles will work against each other and the central differential will not turn so nothing will drive the gearbox and the engine it is not that difficult to fix this problem we need to remove the cover under the differential to have access to it and fix the orientation the structure is similar on both axles so you can follow the same principle we need to remove the shafts connecting the differential with the wheel hubs before putting the things back together it is good to double check if the axles are properly in place and they are rotating the inner tan gears if your u-joints are not aligned properly then this is how you can disconnect the shafts and rotate them in the proper position this is what you can experience if that small cross blocks at step 65 was put in the wrong way and it is blocking the rear wheels if you rotate one rear wheel then the other will rotate in the other direction but you cannot rotate both of them the same time you can see the problem here the incorrect version is at the left and the correct one is on the right so the axle should go in the hole and should be able to rotate freely and this is how you can fix the problem once the model is built the best is to use another axle to push up the small gray one after this you can remove the problematic cross block but be careful and do not pull out the tan axle because it could be difficult to push it back if the tan gear falls out now let’s see how does it look like if the lower attachment points of the

springs are in the wrong hole of the suspension arm as you see the rear of the car is too low the suspension does not work at all the car sits down the front one has the correct setup it works as designed fortunately this one can be fixed really quickly we need to remove the wheel and only a few pieces to get access to the suspension arm since the brown axle is in the wrong hole there is nothing holding it in place it can be removed easily the correct axle hole is the outer one that’s where the brown axle should go the difference is clearly visible suspension now works are designed if you check everything on your car the u-joints and all connections are correct and the car is still cracking I have one suggestion here you can see two builds of the Defender the first one is fresh it was built only a couple of days ago as you can see it runs smoothly in the highest gear without any cracking noise the other one is the Defender I used in my previous videos it was sitting on the shelf collecting dust for about six months despite having the correct set up it is very sluggish and produces that awful cracking noise so how could it be fixed? I think just like any other car that was standing still for a long time you need to take it apart, clean it and put it back together as you see you really get the full Land Rover owners’ experience with this car! If you found this video useful then please give it a thumbs up you can also subscribe and tap the notification bell if you want to see more Technic reviews and other LEGO RC videos see you next time bye bye