Is transmission oil the same thing as motor oil?

[trist007]

I went to Auto Zone and told them I needed transmission oil for my 250 2 stroke. They gave me a quart of motor oil. I thought transmission oil was different from motor oil. Or can u just use it as both when it comes to dirt bikes?

 

[FruDaddy]

It is different. Most parts store employees don't know anything about car engines, even fewer know dirt bikes. Search here for tranny fluid recommendations, it has been thoroughly discussed.

 

[BLACKeR]

its different but you can safely run 10W-30 motor oil in a 2-stroke transmission. its a pretty common practice.

 

[xkevenx]

today i used 15w40 or is this wrong?

 

[Jaybird]

15w40 is fine

 

[rmc_olderthandirt]

The manual I have for my two strokes (Yamaha YZ125 & YZ250) says to run 10w-40 in the transmission.

A car will have a different oil for the transmission thant the engine. If the car has an automatic transmission it will use a fairly thin oil that is blended primarialy to benefit the torque converter and the friction bands.. A standard (manual) transmission will typically use a much heavier "gear oil" as there are no friction components and minimizing metal to metal contact in the gears is the primary objective.

The transmission on a dirt bike has requirements between the "gear oil" of a straight gearbox and the specialized requirements of an automatic with torque converter. The clutch operates in the oil bath so you don't want to use an oil that will completely prevent friction.

Rod

 

[IndyMX]

Shell Rotella-T. 8 bucks at Wallyworld!

 

[griffbones]

Indy is telling you WALMART.

Put in 10w-40, 10w-30, ATF type F, or a specific bike oil like BelRay Gear Saver 80w or Honda HP 80-85 two stroke trans oil. They will all work just fine. When buying the car oils stay away from the ones that say energy conserving, as some of these oils have friction modifiers that could possibly make your clutch slip.

 

[Jaybird]

Actually, there is not much in any motor oils today that will actually cause the clutch to slip more than normal. Several years ago this was a problem right at the start of motor oils meeting newer emission and MPG standards, but it was addressed right away and is not the problem it was. Although all the major bike mfgs still recommend to NOT use an EC rated oil. It is basically them covering their butts for what "could" be, and not really a warning.

That being said...
You must be a bit more discerning when choosing a transmission oil. For one thing, trans oil is rated on a differernt viscosity scale than engine oil, and you need to know what weights are similar.
Also, some gear oils DO carry the additives that can absolutely make your wet clutch slip far more than normal. Hypoid type gear oil should be avoided for use in your gearbox.

Here is a chart that shows the relationship of the different viscosity grades: (note how 85wt SAE gear oil is the same viscosity as the upper range of 30wt/ lower range of 40wt motor oil)
<a href="http://s29.photobucket.com/albums/c268/Jaybirdmx/?action=view&current=viscosity_chart.jpg" target="_blank"><img src="http://i29.photobucket.com/albums/c268/Jaybirdmx/viscosity_chart.jpg" border="0" alt="Photobucket"></a>

 

[wr250rider]

The manual I have for my two strokes (Yamaha YZ125 & YZ250) says to run 10w-40 in the transmission.

A car will have a different oil for the transmission thant the engine. If the car has an automatic transmission it will use a fairly thin oil that is blended primarialy to benefit the torque converter and the friction bands.. A standard (manual) transmission will typically use a much heavier "gear oil" as there are no friction components and minimizing metal to metal contact in the gears is the primary objective.

The transmission on a dirt bike has requirements between the "gear oil" of a straight gearbox and the specialized requirements of an automatic with torque converter. The clutch operates in the oil bath so you don't want to use an oil that will completely prevent friction.

Rod

my 1995 wr 250 2 stroke manual also says to use motor oil but i always use belray gear saver 80 weight oil

 

[cr2012]

i have an old 83 honda cr60 i was wondering what kind of motor oil i should use in the transmission?

 

[RM85rider123]

i have an old 83 honda cr60 i was wondering what kind of motor oil i should use in the transmission?

bel-ray gear saver 75W or maybe 80W

 

[youngr51]

Ive used ATF in my trials bikes. :think: Silkolene srg75 in race bikes and trials as well.

 

[D Lafleur]

Strictly Moterex for me, of course I dont pay for it. :) :) I get two race seasons on a KTM clutch with zero issues.