Dog drive on a Lucas Distributor

Is it possible to fit the dog drive on the distributor shaft 180 deg out or can it only go on one way? 1961 3.4 MKII

Hello Tim,

It can only fitted one way.
The connection is out of the middle, that way it can only be fitted one way.

Peter Jan

Thank you Jan.

It would seem that the ‘specialist’ I took the distributor too has ruined the distributor. I’ll now need a new shaft and dog drive. How frustrating!


This diagram from the Service Manual is very helpful. If the rotor doesn’t point to the position of number 6 on the cap (towards the locating hole of the securing plate) then the drive dog has been fitted incorrectly by the ‘specialist’. I wish I had seen the diagram a week ago.

Well, its possible, but wrong; you can cram it in and the dogs would catch on the tips and sort of work, which is probably what happened with the “specialist”.
Notice the offset is very small.
This problem has come up several times in the last couple of years.

Also be aware that it is possible to put the upper rotor shaft in two ways, thus the rotor may point forward or rearward when at TDC on #1 cyl.

And it is possible to put in the lower distributor drive shaft gear 20 ways, as it has 20 teeth.

Don’t buy anything just move the wires in the distributor.


The drive dog can indeed be fit on the distributor shaft 180 degrees out. When disassembling a Lucas distributor, a pin is driven out to remove the the drive dog from the distributor shaft.

When reassembling the distributor, the drive dog can be pinned to the shaft in two ways: 1) in the original orientation that it was removed, or 2) 180 degrees out from the original orientation.

If the drive dog was mistakenly pinned 180 degrees out from the original orientation, the spark plug wires will need to be relocated on the distributor cap. Or more simply, just drive out the pin, turn the drive dog 180 degrees on the distributor shaft, and reinsert the pin.