Alternative lower gear oil.

[OtisBlkR1]

What's a good cost effective alternative to the high dollar cycle shops lower gear oil on dirt bikes ? The new Kid behind the counter tried getting me into $18 "KTM gear oil" and my buddy stepped over, also a employee stated "don't waste you money, and handed me a bottle of 80W gear oil at $9 and stated "all the racers run this in the bottom" I brought it home. it works fine of course. So, Just like RT6 "diesel oil" in my quads and side by sides, whats a good alternative that works perfectly fine ? Ive recently purchased to old 2 stroke dirt bikes, shared sump.

Opinions welcome.

 

[Cujet]

On 2 stroke dirt bikes, people have been using all flavors of oil. A typical alternative favorite is common type F, Mercon or Dextron ATF. Some of the BelRay gear oil I picked up clearly said "meets SAE 10W-40". I suspect it's just motor oil, possibly with extra additives. My KTM 380exc specifies 10W-30 motor oil in the transmission.

I've used Rotella diesel oil, ATF, BelRay gear oil and just about anything else lying around. Gears are nearly indestructible. lower viscosity helps prevent clutch drag. Wear and bearing failure is due to dirt/water/corrosion. Not type of oil in a motorcycle transmission. The secret is to change it often.

Again, motorcycle 80W gear oil is not 80W, 90W or 75W-140 differential lubricant. It's 10W-40 oil. And a diesel oil such as Rotella, in just about any common viscosity, is sufficient.

 

[Ducked]

I've used straight 40 monograde motor oil (CPC) in a 133cc Yamaha RZR 2-stroke gearbox. Seemed fine.

 

[Ducked]

Originally Posted By: OtisBlkR1
Ive recently purchased to old 2 stroke dirt bikes, shared sump.

Opinions welcome.


In my opinion, you havn't, because I don't think 2-strokes have a sump.

 

[Killer223]

we use walmart supertech 5-30 in all our bikes. and we have a lot of them. it's cheep, we change it when changing/cleaning the air filters.

 

[OtisBlkR1]

1997 KTM 300CC two stroke & a 2000 RM 250 two stroke. both machines have lower gear oil. ive already drained the KTM once and refilled it. The premix oil in the gas lubes the top end, the lower gear oil takes care of the gears and the clutch. (if your correcting me for saying sump, I get it, its just terminology, however both bikes have lower gear oil)

 

[OtisBlkR1]

Originally Posted By: Cujet
On 2 stroke dirt bikes, people have been using all flavors of oil. A typical alternative favorite is common type F, Mercon or Dextron ATF. Some of the BelRay gear oil I picked up clearly said "meets SAE 10W-40". I suspect it's just motor oil, possibly with extra additives. My KTM 380exc specifies 10W-30 motor oil in the transmission.

I've used Rotella diesel oil, ATF, BelRay gear oil and just about anything else lying around. Gears are nearly indestructible. lower viscosity helps prevent clutch drag. Wear and bearing failure is due to dirt/water/corrosion. Not type of oil in a motorcycle transmission. The secret is to change it often.

Again, motorcycle 80W gear oil is not 80W, 90W or 75W-140 differential lubricant. It's 10W-40 oil. And a diesel oil such as Rotella, in just about any common viscosity, is sufficient.



great reply, I thought the oil they sold me looked a awfull lot like transmission fluid...

 

[Killer223]

i would not use transmission ATF type of fluid in these. i don't there it has enough lubricity for the gears. yes tehy have a wet clutch, but that's the whole premise behind the oil specs. wet clutch safe.

 

[Cujet]

Originally Posted By: Killer223
i would not use transmission ATF type of fluid in these. i don't there it has enough lubricity for the gears. yes tehy have a wet clutch, but that's the whole premise behind the oil specs. wet clutch safe.


Not so! ATF is perfectly capable of protecting the straight cut gears, ball and roller bearings found in motorcycles.

Many people don't realize that only extremely high gear loading and spiral bevel gears "hypoid" (hyperboliod) gears utilize heavy viscosity lubricants, with robust additive packages. These types of gears "slide" across each other and in combination with the heavy loads, require special lubricants.

Modern cars with manual transmissions use light viscosity oils and often use ATF! This includes FWD cars with the differential and heavily loaded reduction gearing in a transaxle.

 

[Ducked]

Originally Posted By: OtisBlkR1
its just terminology, however both bikes have lower gear oil)


No it isn't.

"Shared sump" means the engine oil is shared by the engine and gearbox/clutch. That isn't the case in a 2-stroke.

So there isn't a sump, and if there was it wouldn't be shared. This is important in this context because you don't have to consider the effect of combustion products and temperatures on whatever you use.

You DO have a wet clutch though, which is important in this context since you'll have to avoid contaminating it with friction modifiers and AW agents.

Automatic transmissions contain clutches and gears so on the face of it they should be about spot-on.

My monograde 40 seemed to work fine too though. Maybe a bit thick for cold starts in a colder climate.

"lower gear oil", is, AFAIK, an exclusively outboard motor term, where it means something.

Words have meaning.

 

[OtisBlkR1]

Originally Posted By: Ducked
Originally Posted By: OtisBlkR1
its just terminology, however both bikes have lower gear oil)


No it isn't.

"Shared sump" means the engine oil is shared by the engine and gearbox/clutch. That isn't the case in a 2-stroke.

So there isn't a sump, and if there was it wouldn't be shared. This is important in this context because you don't have to consider the effect of combustion products and temperatures on whatever you use.

You DO have a wet clutch though, which is important in this context since you'll have to avoid contaminating it with friction modifiers and AW agents.

Automatic transmissions contain clutches and gears so on the face of it they should be about spot-on.

My monograde 40 seemed to work fine too though. Maybe a bit thick for cold starts in a colder climate.

"lower gear oil", is, AFAIK, an exclusively outboard motor term, where it means something.

Words have meaning.



geez o pete man.. "the lower half of the motor" the gears and the clutch.. Pardon me if im not saying it right. Im pretty sure you understand what im getting at..

 

[ccdhowell]

I use Royal Purple Syncromax in the gear cases and transmissions on my quads and side by sides. Not sure if it'll work with wet clutches, could always email Royal Purple. It makes the transmission on my old Polaris very smooth.