filter

hi guys it my first post here, i just bought a pretty solid hk with a modified 173 (higher comp, mild cam extractors, holly 350 etc), with an M20 gb. Ill get pics of her up soon after i degrease and clean her out. but anyway i was wondering what type of oil i should use for the engine and gb.

cheers, Andrew

Smitty2

dunno about the 173
but 140w gear oil (Penrite or Castrol)
is the only thing for the M20

don't use 85-90w or 75-90w gear oils
too thin

and do NOT put in auto trans or ATF..to quicken
the shifts...kills an M20 (or M21)


hth

Smitty

76lxhatch

A good 20/50 for the engine, nothing synthetic

filter

cheers mate
i ended up buying penrite hpr40 oil, and castrol vmx80 gear oil, do you guys think the gear oil will be suitable as another person i was talking to said 140w would be way to thick?

76lxhatch

I've never had any problems with the 75W90 gear oils in M20 boxes myself, have mixed in a bit of 80/90 diff oil before today with the only effect being a very slightly more notchy shift. How come so thick, smitty? I would have thought that would play havoc with the synchros...?

filter

ok thanks man, i just done the oil, ill go and give the gb oil a go, ive never changed gb oil before but looks easy

Smitty2

actually no...and its what I put in all the Aussie 4spd boxes I build/rebuild

but
there is a secret...its a multigrade hypoid gear oil I use..its really a 85w-140 gear oil and its great
why?
its thin when cold ..no probs shifting and when hot it acts like a 140 weight oil and so protects the box and bearings and bushes etc ..great for an Aussie box used in motorsport




and
bugger...better stop giving away trade secrets
took me 30 years to get some of these

Smitty

EH179

i have always used penrite hpr 30 for the old sixes

70rey

ive got a 202 and have been told to use hpr30 in mine.