There are bearings sold individually on Aliexpress, Ebay, Amazon,... Measure the plastic bushes.
https://es.aliexpress.com/item/1005004777368528.html

To find out if the problem is with the transmitter or the car, you can try a 27Mhz hobby transmitter.

In the car there is a trimmer to adjust the throttle travel and the reverse.. Test it.
Everything said here is valid for you.:

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If you have knowledge of electronics and own a multimeter and oscilloscope, my blog-site about the Dictator has diagrams and technical information.
https://reparar-cochesrc.blogspot.co...e-emisora.html


You report the steering works (Ch1) but the throttle (Ch2) does not activate the electric motor, neither in forward or reverse. Sometimes the relay activates in the coil but the contacts are burned.
* Please, try to test the transmitter on another Nikko proportional car or 27Mhz hobby car.
* The batteries must be charged. The old stock 7.2V NiCd battery surely does not have discharge current to activate the motor. Try another battery.
* Clean the contacts of the 7.2V battery box and battery connectors. There is usually sulfate.
* Check the car's ON/Off switch with a multimeter and the solder wires. The sulfate attacks the solders and the copper in the wire breaks inside the insulator.
* Check the neutral trimmers (steering and throttle)
* The relay coil has about 10 or 15 ohms. Check it with the multimeter.
* Pin 4 of 2609AL circuit can see the transmitter signal on the oscilloscope. Pins 19 (forward) or 20 (reverse) are activated with about 4 or 5 volts.
* In addition to a possible relay failure, the problem may be in the power Mosfet transistors or the activation circuit (M5291 i.c.) of the Mosfet transistors.