Triumph Repair: fluids what to use, car engine oil, castrol gtx

Question
Hi jim, I have a question I just got a 1972 spitfire. that has been sitting for 16 years looking to change all fluids. reading the haynes manuel I never heard of some of these fluids so what do you recommend?

manual transmission
carb fluid
engine
rear diff.
brakes
clutch

I just want to be sure I use right fluids instead of me guessing. and causing myself problem down the road.  

Answer
Mark,

Manual trans and differential.  90wt GL-4 (never GL-5) gear oil.  Castrol Hypoy-C used to be GL-4, but I believe it's been reformulated.  The problem is the GL-5 is reputed to attack the brass/bronze shims in the trans and diff.

Carb fluid?  You can buy the SU dashpot oil from the english car parts suppliers, or use a fairly light wt motor oil, 5W30 or 10W30.  Sometimes you need to experiment a  bit to find what works best for your car.

Engine oil? Castrol GTX, of course!  If the car isn't burning excessive oil you might get away with 10W40.  Otherwise look at either their 15W40 or 20W50.

Brakes and Clutch.  Castrol LMA DOT4 brake fluid.  It's an ethylene glycol based brake fluid that resists absorbing moisture.


Cheers,

Jim