MG Car Repair: Replacing Speedometer cable in 1973 MGB, speedometer cable, thumb nuts

Question
QUESTION: How do you replace the speedometer cable in a 1973 MGB. I find it very difficult to reach the cable on the speedometer to remove it. Any ideas?

Thanks,
Robert

ANSWER: Hi Robert,

The rubber dash cars made it very difficult to access the speedometer so you have to remove the heater control knob and the nut under it to remove the heater control from the dash to give you access to the speedometer. You will feel two large thumb nuts on threaded studs in the back of the speedometer. Then you can slide the speedometer out to get to the cable. Some people can reach the cable without removing the speedometer itself if you have small hands but I found it just as easy to pull the speedo out first. Most of the early rubber dash cars had a small 90 degree gearbox on the speedometer to drive the cable.

Howard

---------- FOLLOW-UP ----------

QUESTION: Thanks so much for the quick response, how to you feed the new cable through the firewall rubber gromet. Also what is the procedure for replacing the choke cable. Where is the best points to jack up the car.

Thanks Again,
Robert Wells

Answer
Robert, you need to push the grommet out of the firewall with a screwdriver and if the new cable don't have a new grommet, you need to split the old grommet with a knife or such and put it on the new cable.

To remove the choke cable you need to loosen the pinch nut at the choke link in between the carburetors and pull the cable out. Straighten out any kinks in the cable end that was pinched and just pull the choke knob and cable out of the housing to lube or replace the cable. If you are replacing the housing also, (not easy) You need to remove the nut on the back of the dash that is on the cable housing. Then examine the housing to see if any clamps are installed anywhere along the housing. (it is not necessary to remove the rubber grommet that the housing goes through as the housing will slide through it.

The MG was supplied with lugs on the bottom of the body just below the door on each side. This lug is to insert the MG jack to jack up either side of the car.

If you are using a floor jack, you can put it under the front large cross member on the front or under the center of the differential for the rear. Don't use any of the frame members on the body to jack up the car.

Howard