PLACING OF THE BALL BEARINGS The ball bearings must fix their places a bit tighten but not too much, since then they get rubbed, become harder and they increase their temperature until a possible breaking. It is very important that they fit well lined up since the beginning in order to avoid marking or deforming its place.
Avoid using a hammer for its installation, it is better to use a vice or any other tool which gives a constant pressure by means of a screw rather than by strokes.
You can slightly modify the dimensions of the piece to adjust by means of temperature. If the ball bearing is hard to fit, heat the piece which holds it with a hair or industrial dryer until it burns, the temperature will increase the diameter enough to fit in a softer way.
You can do the contrary with the bearing. Put it in the freezer for a while and put it in its place while it is very cold. This low temperature will provoke a clear contraction of the piece that, together with the dilation of the place due to heat, can facilitate the assembling operation a lot.

ADJUSTING TRANSMISION SHAFT When you place the 12 teeth gear at the transmission axle, do not tighten it against its ball bearings. Leave a bit of clearance, between 0 and 0,5mm, so that the axle has a bit of axial movement. You will reduce the temperature of the functioning of the transmission, softening its working and endurance the bearings’ life and the plastic big gear.
Once the gear is placed, tighten it strongly placing medium screw locker (blue Loctite 243 or similar) at its bolts without head.

This axial movement can also be searched for in the differential socket, achieving thus identical benefits.

CHOOSING SCREW-LOCKER The first rule to follow when assembling an aluminium car for competition is that all, ALL, ALL the screws must be assembled with some drops of screw locker. It is also important to choose the screw locker with a suitable hardness. We use Loctite screw locker. We use pink 222 soft Loctite for all the car’s screws. For the screws that hold the transmission pieces, such as gears, wheel cubes, differential, etc., and for the main uprights fixation M5, we use the blue 243 medium Loctite, very resistant to oils and high temperatures.
When assembling a TT car, a 243 Loctite must be used, the blue medium one, in all the screws since it requires a major fixation.

IMPLEMENTING OF SCREW-LOCKER It is very curious to see how the screw locker behaves when the screws are tightened.
If you apply the screw locker in the thread of the screw to be inserted, this screw locker will move to the outer part and the excess can be cleaned up with a piece of cloth. On the contrary, if you apply the screw locker in the thread of the hole where the screw is going to be placed, this liquid will go through the thread, appearing on the other side or getting accumulated at the bottom of the hole. You will sense where is better to put the screw locker in each piece depending on your intentions.
Cautions to take into account: If the piece to be fixed is a gear that goes over an axle or another similar piece, the leftover screw locker of the screw will move between the two pieces, gear and axle, gluing each other. This is beneficial in some occasions because it offers an additional fixation in delicate pieces, but in order to disassemble the pieces, tools like an extractor will be required. This trick is advisable in order to fix the gear of the clutch bell.
In holes and conic screws, always apply the screw locker in the thread of the hole to avoid the screw locker going out the bolt and fixing the conic area, which may damage the bolt when trying to disassemble it due to an excess of fixation.
In closed holes, the accumulation of dry screw locker in the inner part can make blockage and not allow the screw to screw to the bottom provoking even breakings of the piece or of the nut/thread. Clean them regularly with a needle or a punch.