How many splines...

[xvivalve]

...on a 1500HL gearbox input shaft?

[Carledo]

IIRC it's 23, or possibly 21. One of the 2 anyhow!

Steve

[cliftyhanger]

21, I think!
certainly not the 10 of the 3 rail box...

[xvivalve]

OK, how about the 1500TC; was that a different 'box?

[cliftyhanger]

Not sure when the changeover happened, but the 3 rail box is the"coarse" spline(10) and the single rail "fine" (21 or so)

Same thing with the bigger engine boxes, but they all have a slightly larger diameter input shaft too.

[xvivalve]

I’m aware the 1850 changed from 3 rail to single around ‘76, when Dolomite became 1850HL, but with the introduction of the 1500 HL in ‘76 was the same gearbox change coincident with the demise of the TC?

[cliftyhanger]

I wouldn't rely on car build dates, so many have got swapped about. But I think about 1975, so very likely when 1500TC became dolomite 1500, same as Toledo became 1300 dolomite. But I bet it isn't as easy as that with some crossovers at the factory, and many more since.
Don't be shy, do share why you want to know, or at least some more clues

[cleverusername]

I think mine was the fine spline one, doesn't the gate on the gearbox give it away?

[xvivalve]

Simply parts compatibility between the TC and HL

[sprint95m]

For the 1500TC (and indeed the Dolomite(1850)) there was an intermediate version between the
original 1500TC and the Dolomite 1500HL, which had amongst its specification the single rail gearbox.

A few years ago in Dolly Mixture Steve Waldenberg did a comparison between two red 1500TCs, which were both P reg,
highlighting these changes.



Ian.

[yorkshire_spam]

I've got a single rail gearbox in bits in a box in the garage.... happy to go and count the splines? But it's from a Spitfire not a Dolomite.... are they the same?

[MIG Wielder]

Hi Alun, I've got the input shaft here from that " bitsa " gearbox I was given. This is the one with the 1850 WH series casing but with 1500 bell-housing and gear-ratios.
That has 20 splines and 17 teeth on the input shaft cog; Just for comparison the brand new 1850 input shaft I have has 23 splines and 19 teeth on the cog; The 1850 one is also rather longer than the 1850 one.
The 1500 shaft is 22.2 mm O.D. on the splined section, the 1850 one is 25.1 mm on the splined section.
Tony.

[yorkshire_spam]

The input shaft from my single rail Spitfire 1500 'box is 22mm OD, 20 Splines

[xvivalve]

The input shaft from my single rail Spitfire 1500 'box is 22mm OD, 20 Splines

Thanks, yes, they're the same as the 1500HL 'box