Allison Gear Lube

[wndsr]

What is the correct lubricant for an Allison M-20 gear? 30W or 40W non detergent??

 

[J's Dream]

Straight 40W should be used. The same as what is (should be) used in your main engine.

 

[SKYCHENEY]

40wt is preferred for the temperature that we run our boats, but 30wt is acceptable and is in fact recommended for lower temperatures. Short answer: Use the same 40wt as in your Detroits.

 

[Bob Bradley]

As long as the gears have filters (and they should) I would use normal 40w detergent oil - same as the engines.

 

[wndsr]

OK-thats fine-can a detergent oil be used? or better yet-who is everyone using as a supplier?? I cant seem to find a supplier for 40 non detergent.

 

[SKYCHENEY]

I put Exxon XD3 - 40wt in my gears and mains. Look in the phone book for your local Exxon-Mobil distributor and you can pick it up in quarts, gallons, or 5 gallon pails; whatever works for you.

 

[Will]

The detergent in engine oil keeps the contaminating byproducts of combustion in suspension until they are picked up by oil filters or drained during an oil change. There is no combustion in the gear box so detergents aren't required. However, they don't hurt anything either. So, as long as the viscosity is the same, just use engine oil in the transmissions too. Also detergent is usually easier to get and may even be cheaper.
Will