Flat Spot

[LORENZO73]

[david painter]

That's Good easy fix if you can find a orange 20 tooth gear
Dave

[SLOW ITAL]

:

Good call Gil, but thankfully not in this case. Renzo has called me this morning and said that his mechanic has pulled the speedo drive wheel, it a black one with 23 teeth - so mystery solved.

[MarinaCoupe]

I am sending Renzo one on Monday

[LORENZO73]

I am sending Renzo one on Monday

[LORENZO73]

I have another gearbox, and i found the gear speedo green with 21 tooth. Renzo

[LORENZO73]

I have this one like exactly, that i have on the marina. Renzo

[LORENZO73]

I think that i don’t have a 1.8 gearbox on it ? Renzo

[david painter]

I have this one like exactly, that i have on the marina. Renzo7B57C074-AECC-4132-91C8-F3D21C33BBBE.jpeg

Based on you count of gear box teeth that gives you the following ratios
1st Gear 3.11:1
2nd Gear 2.94:1
3rd Gear 1.90:1
4th Gear will be 1:1 as this is direct drive
From my manual these are what is listed for a 1800
1st Gear 3.111:1
2nd Gear 1.916:1
3rd Gear 1.307:1
4th Gear is 1:1 direct drive
I would suggest the gears you have are out of a TR7 or Spitfire
Dave

[david painter]

Dave

[david painter]

The Speedo Drive Pinion 21 tooth Green is Triumph Part number 219002A
From what I can find it is No longer available the only listing I can find for it are TR7/ TR8 fitted with a LT77 5 Speed gearbox The Spitfire parts catalogue does not list it as fitting
Dave

[LORENZO73]

I have this one like exactly, that i have on the marina. Renzo7B57C074-AECC-4132-91C8-F3D21C33BBBE.jpeg

Based on you count of gear box teeth that gives you the following ratios
1st Gear 3.11:1
2nd Gear 2.94:1
3rd Gear 1.90:1
4th Gear will be 1:1 as this is direct drive
From my manual these are what is listed for a 1800
1st Gear 3.111:1
2nd Gear 1.916:1
3rd Gear 1.307:1
4th Gear is 1:1 direct drive
I would suggest the gears you have are out of a TR7 or Spitfire
Dave

Hi Dave,
Many thanks for your work that you make for me.
I am correct with you for sure, because i find many difference in driving.
Hope can find a gearbox 1.8 marina
Many thanks for your help
Renzo

[MarinaCoupe]

These are the Marina Ratios

B449F53F-572D-4203-9348-6B5D77C703FC.jpeg (28.49 KiB) Viewed 3819 times

[MarinaCoupe]

I researched this some time ago

[MarinaCoupe]

Hi Renzo,

I have checked your teeth count and recalculated the gear ratios with the aid of a spreadsheet. Initially I got the same answers as David Painter. These are clearly wrong. However, I think that you have written down the teeth count for the second and third gear Mainshaft and layshaft the wrong way round, so if you write

Second gear as Laygear 21 and Mainshaft 26 then the calculation comes out exactly right at 1.92:1

Equally for third gear as Laygear 25 and Mainshaft 21 then the calculation comes out exactly right at 1.31:1

So this is a 1.8 gearbox - its an easy mistake to make.

Gear Ratio Calculations.png (9.33 KiB) Viewed 3760 times