Hilux 4x4 Forum

Good Evening Mud God & Bear,

Hope all well with you guys by the Grace of the Almighty.

I refer to the above subject matter,

1. Engine Oil: I’ve been using 20W50 Petrol Engine Oil for my Stallion, and I’m satisfied with it. Used to use 15W40 before, but then has been four services, that’s 20,000 kms that I’ve switched to 20W50, and have been happy with it, but nevertheless your suggestions are most welcome. She’s now clocked 266,366 Kms, so I thought of getting a higher viscosity oil than the semi synthetic, as she’s old and has quite a lot of mileage in her.

2. Differentials and Transmissions Oils (with Transfer Case): I’ve been using 80W90 on them, and I replace them every 20,000 kms, so this time her 20,000 kms has been achieved, and I was thinking of going for 85W140. Please suggest what do you think? Should I go for it or stick to the same?

Your assistance and cooperation on this will sincerely be appreciated.

Looking forward to your response on this by return at your convenience.

Best regards
Shermohamed

Hi again. The 20W50 should be fine for the older motor, however changing oil every 5000 km is really unnecessary .... that's what you would do if it was a diesel engine where the oil collects a lot more carbon. On the 4y every 10 to 15 thousand km is good. Also if the average mileage you do is low and you haven't completed 10,000km over a two year period since the last oil change, I would change it again anyway .... it slowly becomes acidic.

Diff and transmission oils only need to be changed every 50,000km unless they have become contaminated with particulate from excessive wear or with water ingress. Stay with the 80W 90 - you may experience notchy or difficult gear changes with the 85W140, especially while the box is cold.

I was away on vacation and could not respond in time.

Best wishes for a happy and prosperous New Year!

The older vehicle factory specs for engines were 20W50. 20W40 is a little thin. The bearing clearances were designed for the thick oil – 20W50 and the user manual of the 4Y engine advises to use 20W50. If she isn’t smoking don’t even consider a higher viscosity oil than the 20W50.

Factory spec for transmission and transfer is EP90GL5 – API – GL-4 (seems to be discontinued)
Equivalent I found - Shell Spirax S2 G 80W-90 GL5 - API GL4 Oil for Manual Transmissions and Gear Sets.

Factory spec for differentials –
Front – EP90GL5 hypoid gear oil - Equivalent for front - Shell Spirax S2 A 80W-90 GL5 – API - GL5 hypoid axle oil.
Rear – 85W140 GL5 hypoid gear oil – can still be found

Stick to the original spec if you can source or the equivalent only, for the best performance and longevity of components and the rest as Mud Dog stated.
I just prefer to change engine oil at 8000km.

Good Evening Bear,

I hope all well at your end by the Grace of the Almighty.

Thank you for your detailed response to the Lubricating System of the Hilux YN67R 4Y, duly noted, and shall remain on the specified lubrications.

KInd regards
Shermohamed