1 series M41 vs M410 Tailshaft

DCW242

Does anyone know if a 164 M410 tailshaft is the same length as a 140 M41 tailshaft? I have a 140 M41 here I want to put in my 142 but it has the bigger flange on it and I was hoping a 164 tailshaft might be a direct fit.

1971_144GL

I don't think it is the same from memory.

You might also find that the diff flange will also then be incorrect if you try to fit a 164 shaft.

The best option is to fit the correct flange, some of the injection model cars had a larger tailshaft resulting in a large flange on some M41

If you have a front section of a m410 164 tailshaft would you be interested in an agreement on a correct flange???? I have a small number of flanges left.

DCW242

Interesting, I had heard they were the same so I've already organised to get a potential M410 tail shaft. If get it would be be interested? A small flange would be good, but then I'd need a tail shaft to suit that, but apparently 1970 and older auto ones will fit. Do you happen to have any other M41 140 parts? I need a column switch.

arebee

Hi All,

I have taken a look at parts catalogues for B20 1800's, 140's and 164's.

I have found out that there are a number of different prop shafts fitted within each model, depending upon year, specification etc….

What I have found out is that the 164 manual (quite sure the M410) cars had part number 678853-3 for the front shaft, a part number also used for the front shaft on B20 1800's, and also 140's.

As for the rear prop shaft, part number 678852-5 and 678853-3 are shared between 140's and 164's. 1800 cars are of course a shorter wheelbase, so a rear prop shaft from one of these will not be long enough (approx 6 inches short).

So my qualified answer is that the larger type universal joint drive shaft from a M41 equipped 140 series car should fit a M410 equipped 164, and vice versa. Only the front prop shaft from a 1800 (large type universal joint, part number 678853-3) should fit a M41 140 / M410 164, based on part numbers.

Naturally as we are now up to 55 years or so after these cars were made, it will be essential to ensure that the specification of the various bits in question are checked to ensure cross fitment. from part number alone, it is possible.

Hope that this helps..

1971_144GL

Yes I am interested in the tailshaft if it goes that way. I have one that is the larger diameter and larger flange but it is very rusty. I was going to shorten a 240 shaft part to copy it.

I don't have any spare levers for od engagement sorry and only have those in my two OD equipped 144 cars 71 and 73 . I understand that they are nla which is a pity as I am waiting a couple more

Interesting to hear those thoughts on the part numbers. I have only really seen the small diameter shafts on 140 cars before 1974 and then they seem to be larger on the injection cars. On the 164 cars it's a thicker tailshaft in my experience. My memory was also that there is a small length difference between the M41 and m410 gearbox, but I should check to confirm. Memory fades.

But yes, if the small flange is the critical part please let me know.

arebee

I have directly compared the length of an M41 (J-type) with an M410 out of an 1800E. There is no difference in length. Having said that, the larger output flange is around 15 mm (or so) longer than the smaller output flange, (I swapped a larger output flange off an M410 for a smaller one), and found the gearbox lengths to be identical.

1971_144GL

That jogs a memory. I think it was about an inch difference or so and my concern was that the central spline wouldn't be centred and it would sit too close to one end or the other, and not allow for full movement as the engine and diff move, for example on hard breaking and pot holes or speed humps.

I will hunt out some bits to check what I can find.