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Re: Flat Spot

Posted: Fri May 08, 2020 2:50 pm
by LORENZO73
02E131CA-5B2C-4FBA-BE9B-36D4BE6E5A4F.jpeg

Re: Flat Spot

Posted: Fri May 08, 2020 6:41 pm
by david painter
That's Good easy fix if you can find a orange 20 tooth gear
Dave

Re: Flat Spot

Posted: Fri May 08, 2020 8:42 pm
by SLOW ITAL
:
MarinaCoupe wrote: Fri May 08, 2020 12:20 pm 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.
:thumbup: :thumbup:

Re: Flat Spot

Posted: Fri May 08, 2020 11:04 pm
by MarinaCoupe
I am sending Renzo one on Monday

Re: Flat Spot

Posted: Sat May 09, 2020 2:14 pm
by LORENZO73
:thumbup: :thumbup: :thumbup:
MarinaCoupe wrote: Fri May 08, 2020 11:04 pm I am sending Renzo one on Monday

Re: Flat Spot

Posted: Sun May 10, 2020 1:13 pm
by LORENZO73
I have another gearbox, and i found the gear speedo green with 21 tooth. Renzo
13BB85EA-9098-4460-8587-781DA348DE64.jpeg

Re: Flat Spot

Posted: Sun May 10, 2020 7:25 pm
by LORENZO73
I have this one like exactly, that i have on the marina. Renzo
7B57C074-AECC-4132-91C8-F3D21C33BBBE.jpeg

Re: Flat Spot

Posted: Sun May 10, 2020 7:27 pm
by LORENZO73
I think that i don’t have a 1.8 gearbox on it ? Renzo

Re: Flat Spot

Posted: Mon May 11, 2020 5:33 pm
by david painter
LORENZO73 wrote: Sun May 10, 2020 7:25 pm 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

Re: Flat Spot

Posted: Mon May 11, 2020 5:36 pm
by david painter
gearbox teeth.jpg
Dave

Re: Flat Spot

Posted: Mon May 11, 2020 5:44 pm
by 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

Re: Flat Spot

Posted: Mon May 11, 2020 7:59 pm
by LORENZO73
david painter wrote: Mon May 11, 2020 5:33 pm
LORENZO73 wrote: Sun May 10, 2020 7:25 pm 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

Re: Flat Spot

Posted: Mon May 11, 2020 9:07 pm
by MarinaCoupe
These are the Marina Ratios
B449F53F-572D-4203-9348-6B5D77C703FC.jpeg
B449F53F-572D-4203-9348-6B5D77C703FC.jpeg (28.49 KiB) Viewed 3882 times

Re: Flat Spot

Posted: Mon May 11, 2020 9:14 pm
by MarinaCoupe
I researched this some time ago
BFEA6E9F-6265-4B5B-8F58-9B7D636DE298.png

Re: Flat Spot

Posted: Wed May 13, 2020 3:20 pm
by 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
Gear Ratio Calculations.png (9.33 KiB) Viewed 3823 times