[6pack] Proper gearcase oil

[William McIntire]

All
Have more info that supports our use of 80/90 wt oil in the transmission/OD units.  Have a factory repair and operations manual.  Published by, " Triumph Motor Company Ltd, Coventry England" part # 545277, published 1972.

With respect to transmission and OD lubrication it says...
Gearbox and overdrive over 30 deg F - BP Gear oil  SAE 90 EP
                                  below 30 "     "  - BP Gear oil  SAE 80 EP 
Both are API GL4  

As I remember there is a communication port (hole) between the trans and OD units (at least on the 'A' type units). Different weight oils in the respective units will mix with time and become whatever they mix to.  Transmissions are the same from TR2 through TR3A's. 3B through 4's had 1st gear synchronized and possibly caged needle bearing rather than free floating ones in the counter shaft, lot of broom handles were saved there by not needing them for bearing support on reassembly, and different shift lever on the TR4's. Strongly suspect TR6 trans is the same as Late TR4 boxes but have never had one apart (mine hasn't broken yet).  

This is sort of a FWIW thing. People can use whatever they are comfortable with. I'm with Bruce using 80/90 wt.    Times and lubricants have changed, may be a 'hotter set up' out there, but this is what the book of the time said. 
Bill
'70   6 



----- Original Message -----
From: Bruce Simms <brucesimms2003 at yahoo.ca>
Date: Friday, October 1, 2010 3:33 pm
Subject: [6pack] Proper gearcase oil
To: 6pack at autox.team.net

> I have a copy of an old Standard Motor Company service manual 
> (pre J type) for
> Laycock de Normanville overdrives.   It specifies 30 
> wt non-detergent oil.  
> It 
> specifically says not to use extreme presuure gear oils as the
> "centrifugal 
> effect of the planets may separate some of the additives of the
> oil and cause 
> sludging."
> 
> That is definitive advice.
> 
> However, In my 6 I have
> Redline MT90 in my A type and I get compliments on how 
> well it works.  I'm
> not switching.
> 
> Bruce Simms