[TR] gearbox oil

[Jim Muller]

On 5 Sep 2008 at 13:11, Tony Childs wrote:

> I chose to go with straight grade SAE30 oil; in my D-Type overdrive
> when I installed it in my Spit.  I have no delay in engagement or
> disengagement and no slippage at all.  Trans shifts smoothly and no
> noisy gears.

When I first installed a rebuilt gearbox w/OD from QM I used non-D 30 
as John E recommended.  It worked okay (after I replaced the solenoid 
and then the entire OD, but that's a different story).  But what I 
also observed was that the shifting behavior changed with gearbox 
temperature.  Perhaps it is because the only non-D oil I could find 
was probably pretty cheap stuff, but it seemed to thin out rather 
badly as the box warmed.  When I recently switched to Valvoline 
Racing Oil 20w50, that behavior went away.  Now it feels smooth and 
lightly damped no matter the temperature.  And the OD works like a 
charm, as God and L. de N. intended.

Just my observation.  YMMV.

-- 
Jim Muller
jimmuller at rcn.com
'80 Spitfire, '70 GT6+