HTF C3 for L90 Transmission/Dropbox?

[El Smith]

Hi All,

The manual for my Volvo L90 spec's "HTF C3" for the transmission lubricant.
But i'm not having to much luck finding that.
Am i good to use straight ATF?
I'm not sure what's in there now. Is some kind of flush required?

 

[Nige]

C3 is an Allison transmission oil specification. A large number of transmission/power train oils will meet that spec, or the newer C4 specification.
More importantly, what viscosity of oil does the manual call for..?
A clue as to what's in there now might be the colour. What colour is it.?
IMO you should not be using ATF in this application.

 

[Se.la]

Volvo uses engine oil 10w30 or 15w40 for the transmission for the old machine.

 

[El Smith]

Ok, so no to ATF.
Here's the page from the manual.

I guess I'll go with 10w-20 for the transmission.
There's nothing on the dipstick, so it must be pretty low. I'll have to drain it to see whatever currently in there.

From the table it looks like the same can be used for the dropbox. But someone wrote "gear oil" on the dropbox filler cap.
Any thoughts on that?

 

[Se.la]

if you have 10w20 stock , you can use this oil on all, Hyd, trans, drop box ,engine , brake, only 1 kind of oil to keep.

 

[El Smith]

Thanks everybody!