2-stroke owners who use ATF - question

queen of spodes
Edited Date/Time 3/8/2021 5:17pm
Have you ever run Mercon V in your 2-stroke gearbox? I have 2 cases of the stuff in my shop from an old truck that I can't use anymore.

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CKNY
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CKNY 3/3/2021 5:40pm
3/3/2021 5:40pm
queen of spodes wrote:
Have you ever run Mercon V in your 2-stroke gearbox? I have 2 cases of the stuff in my shop from an old truck that I...
Have you ever run Mercon V in your 2-stroke gearbox? I have 2 cases of the stuff in my shop from an old truck that I can't use anymore.

I’ve only run Type F myself .
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RDT
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RDT 3/3/2021 7:25pm
3/3/2021 7:25pm
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good for clutches, but bad for gears. There's better oils to use. I would use something designed for your gearbox.
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UGOTBIT
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UGOTBIT 3/4/2021 5:10am
3/4/2021 5:10am
I'm not very smart, but there are gears inside of automatic and manual transmissions, as well as transfer cases that call for using ATF...

I also run Type F, no issues and it's so cheap you can change it much more often than other oils.
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AxlBundy
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AxlBundy 3/4/2021 5:24am
3/4/2021 5:24am
Ive got a kid with a KTM 50 so Im running B&M Trick shift in the clutch. In the name of simplicity, I just put it in my 200 w/ Rekluse and it seems to be a noticeable improvement so far. In the kids old PW, when I changed from Rotella to ATF, it was a huge difference.

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seth505
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seth505 3/4/2021 6:37am
3/4/2021 6:37am
When I was in high school and a poor kid, I'd do a 50/50 mix type F and 10w-40.
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CKNY
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CKNY 3/4/2021 7:15am
3/4/2021 7:15am
RDT wrote:
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good...
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good for clutches, but bad for gears. There's better oils to use. I would use something designed for your gearbox.
That doesn’t make a lot of sense. Take a look inside an auto tranny. ATF works great just like other hydraulic fluids do.
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cdoggy81
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cdoggy81 3/4/2021 7:48am
3/4/2021 7:48am
ATF F is what I have used for years. Works great & cheap. Maybe it is the special friction modifier it has in it IDK but never had any problems in my tranny. I have not tried any Dextron based ATF but I’m sure it would be fine too. Same with the Mercon to answer your original question. I think the key is to make sure you change it every few rides & keep the fluid clean.
You can mix ATF with other ATF if in a pinch but I would not mix it with motor oil..... You can run motor oil in the tranny though as I did when i was a poor kid too. I mean it was only $.99 a quart back then but I have since seen the light as well as have a good paying job so now I can afford the better stuff LoL 🤣
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RDT
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RDT 3/4/2021 8:59am
3/4/2021 8:59am
RDT wrote:
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good...
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good for clutches, but bad for gears. There's better oils to use. I would use something designed for your gearbox.
CKNY wrote:
That doesn’t make a lot of sense. Take a look inside an auto tranny. ATF works great just like other hydraulic fluids do.
Apples and oranges, Wesson oil will work also, optimum, not by a long shot. You guys need to study up on oils and their functions
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CKNY
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CKNY 3/4/2021 10:10am
3/4/2021 10:10am
RDT wrote:
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good...
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good for clutches, but bad for gears. There's better oils to use. I would use something designed for your gearbox.
CKNY wrote:
That doesn’t make a lot of sense. Take a look inside an auto tranny. ATF works great just like other hydraulic fluids do.
RDT wrote:
Apples and oranges, Wesson oil will work also, optimum, not by a long shot. You guys need to study up on oils and their functions
No we don’t because we(many, many thousands of people) have used ATF for decades with no negative results. Just like I don’t need to study whether Rotella works great in offroad motorcycles engines and transmissions. You wanna pay $20 a litre for some so called fancy gear oil, knock yourself out. The rest of us will keep using what we know works.
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queen of spodes 3/4/2021 10:47am
3/4/2021 10:47am
Also this thread is titled "2 stroke owners who use ATF", so if you don't use it, great find another thread to enjoy instead of this one.
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rjg
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rjg 3/4/2021 11:10pm
3/4/2021 11:10pm
I use ATF and car engine oil in my 2t tranny. Never had issues.
queen of spodes 3/5/2021 6:32am
3/5/2021 6:32am
Question is about mercon 5 specifically, anyone run it and how was it?
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FGR01
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FGR01 3/5/2021 7:54am
3/5/2021 7:54am
I tried Type F when I was young and broke. Could buy a case for like $12. Problem was the shifting got notchy and clutch feel noticeably degraded quickly. So I ended up changing it every ride. At that point, you're not really saving money since you can just buy the correct MX gear oil that actually is intended for the job and change it out a lot less often.
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CKNY
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CKNY 3/5/2021 9:00am
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FGR01 wrote:
I tried Type F when I was young and broke. Could buy a case for like $12. Problem was the shifting got notchy and clutch feel...
I tried Type F when I was young and broke. Could buy a case for like $12. Problem was the shifting got notchy and clutch feel noticeably degraded quickly. So I ended up changing it every ride. At that point, you're not really saving money since you can just buy the correct MX gear oil that actually is intended for the job and change it out a lot less often.
Funny because some manufacturers actually recommend ATF in certain models. ATF also gives the clutch a different feel than say a motor oil. Harder more positive feeling engagement often with ATF. What exactly is the correct oil you speak of?
FGR01
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FGR01 3/5/2021 11:40am
3/5/2021 11:40am
FGR01 wrote:
I tried Type F when I was young and broke. Could buy a case for like $12. Problem was the shifting got notchy and clutch feel...
I tried Type F when I was young and broke. Could buy a case for like $12. Problem was the shifting got notchy and clutch feel noticeably degraded quickly. So I ended up changing it every ride. At that point, you're not really saving money since you can just buy the correct MX gear oil that actually is intended for the job and change it out a lot less often.
CKNY wrote:
Funny because some manufacturers actually recommend ATF in certain models. ATF also gives the clutch a different feel than say a motor oil. Harder more positive...
Funny because some manufacturers actually recommend ATF in certain models. ATF also gives the clutch a different feel than say a motor oil. Harder more positive feeling engagement often with ATF. What exactly is the correct oil you speak of?
The 3 I have the most experience with going back 30+ years are Bel-Ray Gear Saver, Maxima MTL, and the Honda gear oil in the red nipple bottle. I am sure there are others that are also excellent that's just what I have used. I mostly stick to the Bel-Ray and currently use the 80W in my Husky 2-stroke transmissions. I change it every 5 hrs and there is no change in shifting or clutch feel. Could probably easily go longer.
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CKNY
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CKNY 3/5/2021 1:32pm
3/5/2021 1:32pm
FGR01 wrote:
I tried Type F when I was young and broke. Could buy a case for like $12. Problem was the shifting got notchy and clutch feel...
I tried Type F when I was young and broke. Could buy a case for like $12. Problem was the shifting got notchy and clutch feel noticeably degraded quickly. So I ended up changing it every ride. At that point, you're not really saving money since you can just buy the correct MX gear oil that actually is intended for the job and change it out a lot less often.
CKNY wrote:
Funny because some manufacturers actually recommend ATF in certain models. ATF also gives the clutch a different feel than say a motor oil. Harder more positive...
Funny because some manufacturers actually recommend ATF in certain models. ATF also gives the clutch a different feel than say a motor oil. Harder more positive feeling engagement often with ATF. What exactly is the correct oil you speak of?
FGR01 wrote:
The 3 I have the most experience with going back 30+ years are Bel-Ray Gear Saver, Maxima MTL, and the Honda gear oil in the red...
The 3 I have the most experience with going back 30+ years are Bel-Ray Gear Saver, Maxima MTL, and the Honda gear oil in the red nipple bottle. I am sure there are others that are also excellent that's just what I have used. I mostly stick to the Bel-Ray and currently use the 80W in my Husky 2-stroke transmissions. I change it every 5 hrs and there is no change in shifting or clutch feel. Could probably easily go longer.
All very good oils.
I’m partial to Maxima for my 4 stroke engines but honestly I personally would not spend the cash to put it in my tranny. I’ve just had such good results in so many brands running Type F and Rotella T4.
Tracktor
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Tracktor 3/8/2021 11:07am
3/8/2021 11:07am
I've used it on an off in different bikes. I don't see where Mercon vs F vs whatever would make a difference. I usually run a change through after a clutch gets burned out as ATF has decent detergent properties. Never had an issue with it that I can remember so I'd have no problem running it again if needed. I would probably test it on specific bike for change intervals & feel though........
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cdoggy81
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cdoggy81 3/8/2021 11:26am
3/8/2021 11:26am

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queen of spodes 3/8/2021 11:40am
3/8/2021 11:40am
Tracktor wrote:
I've used it on an off in different bikes. I don't see where Mercon vs F vs whatever would make a difference. I usually run a...
I've used it on an off in different bikes. I don't see where Mercon vs F vs whatever would make a difference. I usually run a change through after a clutch gets burned out as ATF has decent detergent properties. Never had an issue with it that I can remember so I'd have no problem running it again if needed. I would probably test it on specific bike for change intervals & feel though........
Thanks, I have so much Mercon on my shelf. Gonna try a quart on my next gearbox change.
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captmoto 3/8/2021 5:17pm
3/8/2021 5:17pm
CKNY wrote:
That doesn’t make a lot of sense. Take a look inside an auto tranny. ATF works great just like other hydraulic fluids do.
An auto trans is carrying lot's more fluid, I think my truck calls for 14 quarts. My FC450 calls for 1200 ccs. An auto trans doesn't see the RPMs a bike sees. You can get a good name brand oil for just a few bucks more than a trans fluid.
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godog
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godog 3/9/2021 6:53am
3/9/2021 6:53am
Using any ATF in a motorcycle gearbox will work perfectly fine on the mechanical bits and pieces, the only thing to remember is that ATF doesnt hold contaminates in suspension to be carried to a filter and removed. ATF allows contaminates to fall out of suspension and gather in the pan. If you use it in a motorcycle trans do a good warm up cycle and get the oil circulating thru everything before you pull the drain bolt.
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UGOTBIT
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UGOTBIT 3/10/2021 7:53am
3/10/2021 7:53am
CKNY wrote:
That doesn’t make a lot of sense. Take a look inside an auto tranny. ATF works great just like other hydraulic fluids do.
captmoto wrote:
An auto trans is carrying lot's more fluid, I think my truck calls for 14 quarts. My FC450 calls for 1200 ccs. An auto trans doesn't...
An auto trans is carrying lot's more fluid, I think my truck calls for 14 quarts. My FC450 calls for 1200 ccs. An auto trans doesn't see the RPMs a bike sees. You can get a good name brand oil for just a few bucks more than a trans fluid.
Think of the internal speeds inside the trans...

Some manual transmissions call for ATF, they have no where near the fluid capacity of an automatic transmission.
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2stroke rider 4/29/2025 7:18pm
4/29/2025 7:18pm
queen of spodes wrote:
Have you ever run Mercon V in your 2-stroke gearbox? I have 2 cases of the stuff in my shop from an old truck that I...
Have you ever run Mercon V in your 2-stroke gearbox? I have 2 cases of the stuff in my shop from an old truck that I can't use anymore.

I thought Mercon V had friction modifiers in it so people usually run type F because it has no modifiers which is what you want on a wet clutch

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3strokemx
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3strokemx 4/30/2025 6:24am
4/30/2025 6:24am

I've seen people use ATF as fork oil.   Seems like it works fine.

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jameslowry
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jameslowry 5/1/2025 12:44pm
5/1/2025 12:44pm

Maxima MTL

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Kidkawie 5/2/2025 4:14pm
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RDT wrote:
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good...
Years ago ran in in KTM transmissions. When it got hot on enduros and cross country, it broke down and shifting got rough and notchey. Good for clutches, but bad for gears. There's better oils to use. I would use something designed for your gearbox.
CKNY wrote:
That doesn’t make a lot of sense. Take a look inside an auto tranny. ATF works great just like other hydraulic fluids do.

I ran ATF for a while and noticed notchy shifting.  Went back to 10w40. ATF is fine and may feel fine in other bikes, but its not unheard of the shift feel can be different.

I use ATF in my vintage streetbike forks.  I think its equal to 7 or 10wt.

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Falcon 5/5/2025 12:21pm
5/5/2025 12:21pm

You can use virtually any oil that does not have excessive amounts of friction modifiers in it. This means do not use newer synthetic automotive engine oils with ratings of SK or SI (Or anything labeled "Fuel Conserving.")

Transmission-specific oils like Bel-Ray Gear Saver are awesome because they don't have the additives for combustion engines built in, and they can afford more shear strength additives. I'm not familiar with ATF, but I'd guess that it falls in line with these kinds of products.

You can still get by on motorcycle engine oils, but these might not last in a transmission quite as long. 

 

FilthyGrungy 5/8/2025 4:54am
5/8/2025 4:54am

If I was told Gearsaver is just an ATF, I wouldn’t be shocked at all. 

Theres ATF, and then there’s Rotella. You can make your own blend to hone in on the feel you want

jameslowry
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jameslowry 5/8/2025 7:35am
5/8/2025 7:35am

OMG how can you spend the the money on a race bike & skimp on the oil?? Like the the mechanic once said you can pay me now or pay more later

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philepe747
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philepe747 5/8/2025 11:41am
5/8/2025 11:41am
jameslowry wrote:
OMG how can you spend the the money on a race bike & skimp on the oil?? Like the the mechanic once said you can pay...

OMG how can you spend the the money on a race bike & skimp on the oil?? Like the the mechanic once said you can pay me now or pay more later

ATF does not have the same lubricating properties as engine oil or gear oil.  ATF is probably great for the clutch pack, but I just can’t feel comfortable that it will lube the transmission gears sufficiently.

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