First the Inspection of the Rear End
First unscrew and remove the chassis from the body. Then remove both of the rear tyres. Hold the Model up so you have a good view of the rear rims and axle. Rotate the axle at a steady rate and look for any irregularities.
Things to look for and fix
Grab each rim, gently try and rotate each rim in opposite directions. This will pick any loose rims on the axle, if you find a loose rim, it will need to be glued. Also check the rims for defects, especially for cracks in their hubs.( This also can be fixed with a Brass or Plastic sleeve over the hub to prevent the crack from opening again) Now Check how well the bearings are seated in their holders, by gently moving the axle up and down and side to side. It’s no big deal if they move a little, in most cases they can be effectively glued with Super Glue. Check for any slop between the axle and bearings. Some of the Slot Car makers have oversized bearings; these may need to be addressed to achieve a tighter fitting bearing. If this is the case, Place a small amount of Super glue between the busher's and axle ( Where they meet ) then place the slotcar back onto the track and hold the car upright while keeping the wheels turning (With your Controller). After a short while the wheels will become nice and free again Now without any slop, Just add a little oil to the Busher's and your away and running.
Wheels are now not True
If you find High and Low spots on the rims, then they will need to be sanded flat using your Slotcar Controller and some Sandpaper glued to a Wooden block. This is the best way to achieve a nice and true rim. vibrations should disappear once the rims is round and true. Now that the rims are true, Its time to place your Tyres back over the rims and start the sanding process all over again! After a little while you should notice no more Hopping. Finally you can now Carefully clip the axle back into the chassis. Add a little Super glue on top of the Bushers where they meet the plastic clips and to add a little oil to the rear gears.
Onto the Track
Now testing your slotcar you will need to Accelerate down a long flat straight, looking for any Hopping at the rear end. If you find that your slotcar is still bouncing around, then the tyres are not sanded properly! Also you should note when cornering to check if the Car slides well and the tyres are not grabbing. To eliminate this you will have to round of the outer edge of each tyre by using some torn sandpaper and your fingers to achieve a rounded edge on the tyre wall.
Next the Inspection of the front end
You will need a setup board for this, (Or find an old DVD cover and cut a slot in it). Now the main aim is to check the ride height of the guide and front wheels (tyres). The easiest way to get the most of the guide into the slot is to sand down the tyres to the right diameter. Although on some cars, this can result in a lot of sanding. Another method is to place a copper sleave over the axle and to a set to a determined height. If your going to sand the tyres down, you will need an old rim mounted on a spare axle. Now insert the axle into the hand drill, Now place the tyre to be sanded onto the rim and place the wheel now onto the sanding block you have and sand to the determined height. You will only need to do this at a slow speed.
Checking the Guide
If you find that your guide is to loose, Then apply some glue to the edge of the Guide hole and wait until dry. Now find a drill bit with the correct size you need and hand twist the guide hole to remove the unwanted glue. Replace the guide and add a little oil.
To get rid of that dreaded Noise, you will need some abrasive Toothpaste. Just smear some paste onto the gear, and run the Car for about 5 to 10 minutes while still applying the paste to gears. When you hear the Gears starting to Mesh without the noise, Then clean the paste from the gears, and then apply oil onto the gears.
Preparing the body
What we like to do is to leave the Car bodies loose on the chassis. To do this Lightly sand or scrap with a hobby knife the outer areas of the body, where chassis touch. Also Lightly sand the outer chassis to where they meet the body. Now find a drill bit that is one size larger than the original hole in the chassis where you removed the screws from and hand drill the Holes larger. This will allow for the Screws to not bite onto the edge of the chassis Hole. This setup can improve handling greatly.
Preparing the Motor
There is not much we do here, Except to add a little oil to both ends where the shaft extrude from the can. Also add a little Super glue to the engine mountings to stop the Engine from shifting from side to side under Acceleration.
The braid should always be kept clean. Get yourself some WD40 and a clean rag, Now spray the WD40 onto the rag and wipe the braids clean. As you will see that by doing this your car will achieve a much better contact.
Cleaning the Tyres
We do not use any adhesives or WD40 to clean tyres. If you require to clean you tyres just use a little spit or water on a rag with your finger tips and rub tyres in both directions. Too easy.
Presentation of your Racing Car
Always try and keep all of your broken wings and mirrors that you have lost while racing, so they can be re-glued for your next racing event. This way all cars will look like they should. (not only this , but your cars will be worth more when selling in the Future)
Disclaimer: All the information and advice above are suggestions only. There may be other Tuning and better methods available on the web.