MGB GT Loose gear knob fix

The gear knob in this car is loose, it flaps about loosely on the gear-stick but also buzzes annoyingly when driving. The knob I have is the black plastic type with overdrive switch in the top.

There is an indentation in the front of the knob, inserting a screwdriver here allows the cap (with switch) to pop off.

Indentation at the front of the gear knob to release cap.

 Inside the cap are the two wires that connect to the overdrive switch. These pass up the hollow gear lever. You can also see the ring nut that secures the knob from the inside.

Wires and ring-nut visible inside knob.

 Unscrewing the ring-nut carefully with a narrow screwdriver blade allows the knob to be pulled off.

Ring nut

 There is a slot up the side of the gear-lever and a corresponding ridge on the inside of the gear knob. This engages as a key to prevent the knob from turning and hold it steady.

Slot in gear lever and ridge/key inside gear-knob

 However in my case the wires inside the lever had split. They had been repaired with insulating tape which worked electrically. However it was a bulky solution and the wrapped wires wouldn't fit back inside the lever. Instead the wires filled the knob location slot (not a phrase you hear everyday) and prevented the ridge from locating securely into the gear-lever. As a consequence my gear lever could twist through + /-about 45 degrees. This I think is why the ring nuts wouldn't stay tight

I removed the tape and covered the split wires with shrink tubing

 For a much neater finish.

 I screwed the chrome bevelled nut down wards as far as it would go and then lined up the ridge/key in the knob with the slot in the gear-lever.

Ridge/key inside gear knob

I then cut a small square of heat-shrink tubing to bridge the slot in the gear lever as I pushed the knob down.This tubing is used just as a packer, not for its heat shrinking ability. I could then push the knob down engaging the ridge in the slot over the piece of tubing which  took up any wear and corresponding looseness in the ridge so that it sat securely on the knob.

Pushing the gear lever down over a patch of tubing covering the slot

Down as far as it will go.

I marked the contacts and the switch so that I could tell easily where the positive wires connected, and then refitted the cap

Finally The lower chrome bezel nut was secured tightly against the gear-knob. So far the knob has remained secure and the annoying buzz has been banished. If this doesn't hold I will repeat with Loctite to stick everything in place.