Carrera Gears

How many of you have been disappointed with the performance of you carrera cars? Most of the time its not the motor, but the gearing . Most Carrera come with a 10 tooth pinion gear and 26 tooth spur gear . Giving you a 2.60 gear ratio. Changing the pinion gear to an 8 tooth gear will yield a 3.25 gear ratio. To go even more, a 7 tooth gear will yield a 3.71 ratio. Now as we remember from our hot rod days the higher the ratio the quicker off the line speed. Anyone remember 4.11 gears?

The first thing you will need to do is get some new gears . For this I have found Professor Motor or Cyberslot.net ,follow the link and search for "64 pitch" which is the pitch of the carrera gears. I chose the Camen gears as they were the least expensive ($2.98 at the time of this article).

Once you have gears in hand you are ready to go. First, take out the four screws holding the chassis to the body. Now that the body is off, take out the two screws holding the rear axle hold down and remove. Now the rear axle should come out. Now that the rear axle is out , the pinion gear need to come off the motor. The way that I found was to put an exacto knife in between the gear and the motor support and twist the knife, this should slide the gear off. The motor pinion shaft will need to be shortened so that it will not ride in the groove on the axle gear. This is because the axle gear will have to be moved over to match up with the smaller 7 or 8 tooth pinion gear. Once the motor shaft is shortened to the proper length, it is time to put the new 7 or 8 tooth gear on. The edge of the shaft might need to be sanded to get any burs off and some super glue applied to the shaft to hold the gear tight.

Now that the gear is on, lets take a look at the axle. In this case, the left side of the axle is cut down as shown in the picture below. The spacers on the axle will have to be sanded down or replaced with thinner ones in order to get the gears to mesh right. Having the gears mesh right is important to the smooth running and long lasting of the gears. When this is done you will have to feel the correct placement of the axle and shim and cut accordingly. there should not be very much (if at all) side play of the axle when it is back in place. When the gears seem to mesh right with the wheels back on, put the axle hold-down piece back in. At this time it would be a good idea to give it a test run.

I saw a very big improvement in performance and braking on my 76 ft carrera track with 11ft straight. I think this is a worthwhile project and have done this to a few of my carrera cars with good results. If you have any question about this project please email me at gene@slotcarplace.com