4.56:1 rear axle wanted

Originally Posted by Derek UK

. E.g. the P1800 with a D type uses a black gear with fine teeth. Is that right Mike? Perhaps Mike or Andy could post a list if they have them.

The black gear, unlike all the others, cannot just be swapped, the drive worm on the P1800 M41 is substantially finer than that on a 120 or 140 sourced D type overdrive.

[mike gilbert]

Its true they can't be swapped but there are other ways of getting an accurate reading, such as a geared link in the cable or recalibrated speedo. I suppose it all depends on how the car is to be used, not everyone wants relaxed cruising with (even) slower acceleration.
I was once told that the none overdrive and automatic axles tend to whine less in old age than the OD ones, but I've never driven any none OD cars so can't confirm it.

[Derek UK]

Thanks 500, that confirms what I have in my notebook. I also have "Amazon with D type OD uses M40 tooth size but different coloured drive gear"
The note underneath reads "J type varies!" which isn't much help. I think the Amazon "D" OD ones are light green and the M40 has a white one but can't be sure about that.
I think the various drives have been listed in the Driver at some point and maybe later in the Tech Driver.

[Steve121]

In my opinion having the Overdrive with the standard 4.1:1 axle drops the revs too much for 'comfortable' cruising, and I'm sure that if comparing a 4 speed car and an O/D car at the same speed will result in the O/D car engine showing less RPM than the 4 speed car. I really hate using motorways as they are so boring and prefer smaller roads where the acceleration and handling can be used more, so the O/D axle will be perfect!