Outer Limits 4x4 Board

in the castrol lube guide it says to use castrol EPX SAE 80w-90 in my front diff and to use castrol multitrax SAE 80w-90 in the gearbox and transfer case.i can get as much EPX at work as i want for free and to me they both are the same grade of oil is there any reason why i cant use EPX in my front diff,gearbox and transfer.ive sent castrol an email with no reply these are the description of both oils:

CASTROL MULTITRAX
Manual transmission and differential fluid providing improved gear shift over a wide range of temperatures, particularly cold shift performance. Also suitable in secondary drive axles (front and rear) of 4WD's, for reduced drag and enhanced fuel efficiency, especially in around town service. SAE 80W90, API GL5.

CASTROL EPX 80W/90
Multipurpose gearbox, steering gear and differential oil for passenger cars, light trucks, farm tractors and earthmoving equipment. SAE 80W/90, API GL5.

any help would be great.

Sounds like the EPX is an extreme pressure lubricant more suited to differentials. You could probably get away with running the Multitrax seeing as it's GL-5 rated.

i spoke to a mate last night whose worked for toyota for 13 years and he said it will be fine so ill give it a go and see wat happens i guess thanks mate

you dont run GL-5 oils in the gearbox/transfer

GL-5 has a chemical in it that eats away at the copper synchros in the gearbox

when i got my 75 from dad the mine mechanic through GL-5 in, the box was clunky and hard and the oil when drained was awful!

threw some GL-4 spec VMX-M in and it was smooth as :p

thats wat castrol and toyota recommend so i cant imagine that would be the cause thanks anyway

if you look in the toyota manual it specifies GL-4...

and you can google 'GL4 vs GL5', you'll get PLENTY of results detailing why you shouldnt put GL5 into a GL4 box

GL5 has sulphur oxide or something, cant remember the details.

also if you google and ask what gearbox oil to use on this site or other sites like 4wdaction, most recommend VMX-M or VMX 80, and i think some like agri400 or whateva its called.

just after a quick google:


Hi Guys,

I have an Email from Castrol dated July 27, 2007 about GL4 vs. GL5.

This is an excerpt:

"API GL-5 gear oil designates service of hypoid and other types of gears
commonly found in rear axles. A GL-4 oil may be employed in certain manual
transmissions.

These differences are mainly distinguished by the level of active additives
employed in the product. Different applications require different additive
levels and different component materials can be affected by the levels of
additives present in the lubricant.

Having said that GL-4 and GL-5 gear oils are not compatible and
manufacturer's recommendations should be adhered to. They cannot meet the
same specifications and the product performance and tests are different.

Typically, a GL-5 gear oil will have about 2 times the active additive level
of a GL-4 product. This additional additive can cause problems with yellow
metals like brass or bronze."

i rang toyota australia 1 week ago and the said that the original was the gl4 80w-90 but has now been changed to 75-90 or a straight 80 gl-5 and vmx is a castrol product and on there website lube guide it says to use multitrax 80w-90 gl-5 and agri is for heavy machinary like plant and farm equipment cause we use it in forklifts at work,theres just to many oils out there and not enough info it pisses me off but thanks for ya help

when i first looked up the castrol site and saw it said GL5 after reading GL4 in my manual, this confused me, and that is what got me to do my research.

from experience of my own and from the recommendations of many others, i would recommend VMX-M for the gearbox/transfer, EPX 80w-90 for the front diff, and LSX 90 for the rear LSD (assuming it has an LSD).

i've been running these oils for about 20,000km now and the car always runs perfectly, smooth shifts in the gear box, LSD works well enough even though toyota LSD's are shizenhouse haha. i checked the oil the other day, and it was still pretty good looking.

just trying to help as i dont want to see someone take the gearbox plug out after 30,000km and find the oil full of brass bits, it happened to me when GL5 was put in before...