UTTO (Tractor Transmission Oil) in Gearbox?

[Jabbo]

Hi,
My Holden Rodeo Gearbox and Transfer Case call for the same oil as the engine, or SAE 5W-30. I'm using 15W-40 in the engine.
If I use Penrite Tractor Transmission Oil, SAE 10W-30/75W-80, would I see any bad effects?
At least it's an oil designed for gearboxes, and still meets SAE 10W-30. It also meets API GL4. The cold viscosity isn't really important, as temps here never go below 1oC.

It currently has Caltex Easy Shift 75W-90, but the gearbox feels very heavy when warm.

 

[01rangerxl]

So when you open your owner's manual, it literally recommends using 5W30 motor oil in the trans? Wow. I have heard of that being suggested if the specified fluid is not available, but I don't think I have ever seen it as the primary recommendation in an MT.

I'd probably try to find some Synchromesh or equivalent if 5W30 motor oil is the suggested fluid.

What year is this Holden Rodeo? Some of them look like North American market Colorados, which use a gear oil in the MT, but I have no idea if the MTs are the same between markets.

 

[BrocLuno]

This has been going on for a long time. Allison Transmissions, makers of some of the most rugged off-raod gearvboxes out there, along with Caterpillar, have published lists of fluids that are appropriate for engine and transmission use in shared sump applications.

These fluids have been tested way beyond SAE and API. If they are on the Allison list they are good lubricants and can be used in either engine or drive-line with confidence

http://www.allisontransmission.com/parts-service/approved-fluids/off-highway-fluids

 

[widman]

Synthetic 5W-30 diesel engine oil is what I've used for years when MTF was not available. Now with the 75W-80 GL-4+ formulas out there, recommended for most manual transmissions (sometimes in 75W-85, like Toyota's 75W), you get much better protection in the same viscosity.

75W-90 is definitely too thick.

 

[MolaKule]

Originally Posted By: Jabbo
Hi,
My Holden Rodeo Gearbox and Transfer Case call for the same oil as the engine, or SAE 5W-30. I'm using 15W-40 in the engine.
If I use Penrite Tractor Transmission Oil, SAE 10W-30/75W-80, would I see any bad effects?
At least it's an oil designed for gearboxes, and still meets SAE 10W-30. It also meets API GL4. The cold viscosity isn't really important, as temps here never go below 1oC.

It currently has Caltex Easy Shift 75W-90, but the gearbox feels very heavy when warm.


Yep, a 75W90 is too thick.

Don't fall into the group think of "same viscosity oughtta do ok."

Does your manual transmission gearbox have wet clutches? That's what TTO's were designed for.

The Rodeo Gearbox and Transfer Case use a 10cSt@100C oil which is in the 5W30 range, but the additive chemistry is different.

Check with Pennrite down there such as:

http://www.penriteoil.com.au/products.php?id_categ=4&=&id_products=375