Home Forums Shifter Karts When do you change your gear box oil?

This topic contains 30 replies, has 13 voices, and was last updated by  Thomas Barth 5 years, 7 months ago.

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  • #7540

    Chris Beebe
    Participant

    I know that back when I was riding dirt bikes this was always a hot topic. I would just use ATF and change my oil every ride. Never had any issues. Others would use $$$$ oils and change it every couple of rides. Clearly shifter karts run harder than most trail bikes and I can see it needing to be changed regularly but how often?  I am running honda gear box oil in my shifter and seems to work fine. I just dont feel like pulling  the gear box apart quite yet! Thoughts?

  • #7546

    Ken Shifterkart
    Participant

    I change mine after every race event. For me this includes one practice day & the race day itself. I use Motul Transoil 10W30. I believe that changing it that frequently is “cheap insurance”…

    I’ve heard the ATF is a little too thin and doesn’t have enough or the right kind of high pressure lubricants to withstand the transmission and clutch.

    My engine builder, SwedeTech, highly recommends the Motul Transoil but doesn’t recommend ATF. They rebuild these engines every day and see the gearbox & clutch internals so I trust their judgement.

  • #7553

    Chris Beebe
    Participant

    I would have to agree with you on the ATF in a shifter kart app. You run at 110% all the time where as in a dirt bike app. you do a lot more putting around and its not so hard on the gear box components. I plan on sticking with the honda racing oil that’s in it now.

  • #7605

    Thomas Barth
    Participant

    The TM KZ comes from factory with ATF. Run it all season if you don’t feel like pulling engine for the oil change. Won’t hurt a thing.

  • #7638

    Matt Dixon
    Participant

    You can run the oil in your car all year in you don’t feel like changing it also…

    94y

  • #7639

    Ken Shifterkart
    Participant

    Tom,

    Chris is referring to “moto” engines and not KZ’s because he’s referring to dirtbikes.

    Please take your KZ comments to another thread.

    However, to address your comment, KZ’s have dry clutches (except for Pavesi which are primarily used in road racing) so the gearbox doesn’t share fluid with the clutch like a moto engine. In a moto engine, the clutch during its operation wears away the friction plates, however slightly, and that further contaminates the oil. Due to this, the moto oil gets more contaminants vs a KZ thus my, and SwedeTech’s, recommendation to use a proper transmission oil in a moto engine (like Motul Transoil). Also, ATF is more slippery than transmission oils and will change the clutch activation.

  • #7651

    Chris Reinhardt
    Participant

    A couple of more issues related also….

    The gearbox having a vent tube is open to the atmosphere, and going from a hot state during running to a cold state, parked in the trailer or garage, the oil will collect condensation.  Also, the oil level plug being very unreliable,  I like to drain the oil and refill, so I know I have the proper amount.  And, and…  how much is a quart the best of the best tranny oil compared to the fuel bill  to get you to the track????

    I know everybody is on a budget, but to me it’s like asking how often should I brush my teeth?  As often as you can….

    CR

    Chris Reinhardt

    CR2 Motorsports

    http://www.cr2motorsports.webs.com/

    XV Racing Products

    http://www.xvengineering.com/

    ­­

  • #7671

    James McMahon
    Participant

    Any discussion involving an oil tends to be a slippery one!

    Don’t sweat the small stuff and this is small stuff. Dry or wet clutch, I check level and condition each weekend, change it each season when the cases get cracked open. A season for me is about 4 road races though, so say 8hrs of running, some run a lot more in a year. The car oil analogy doesn’t apply as you don’t (or at least shouldn’t) have combustion byproducts in your gear oil!! The gear surface area is pretty large in these transmissions compared to the torque that’s being transmitted through them.

    I think you could argue either way as to whether MotoX or karting is harder on the tranny. Sure you are WFO in a kart a lot more, but think of the aggressive loading\unloading that happens on the motos. Then there’s the dust…

    Sure, every little adds up, but you have to draw the line somewhere and without any real evidence I think this is where I would draw the line. Check it once in a while, you’ll be fine, and yes I’m talking about oil bath clutches too.

    If you really wanna nerd out, get a UOA done on your used transmission oil, that will tell you EXACTLY whats going on: Viscosity, additives remaining, contamination (gear or bearing material) etc etc.
    ATF can be used (ever pull apart an auto transmission?….series of wet clutches in there) but I’d only do it with fresh plates. Otherwise, just run a good “racing” motorcycle-type gearbox oil, check it and let’r buck. Personally though, I think in this case its a good idea of have the extra anti-shear properties of the racing gearbox oil.

    Don’t overthink it.

  • #7676

    Frank Rapisarda
    Participant

    Chris If your an x- moto cross guy then you know of belray oils. Belray gear saver 85 wt will stand up to the most abuse, or go with the 80 wt. for less drag on the motor, the motul trans oil is excellent chioce also. If you you can afford to change it after every race weekend that is best, but i would not go more than 3 race weekends. Then in the off season have your trans polished, it will shift like butter and last longer, you can do it your self but it takes about a good 8 hrs to do it right.

  • #7718

    Thomas Barth
    Participant

    Matt Dixon said:

    You can run the oil in your car all year in you don’t feel like changing it also

     

    I didn’t say car. I posted the specs for the TM.

  • #7722

    Thomas Barth
    Participant

    Ken Shilling posted:

    I’ve heard the ATF is a little too thin and doesn’t have enough or the right kind of high pressure lubricants to withstand the transmission and clutch.

    Ken please don’t post information that is hearsay. The automatic transmission is way, way harder on oil. That’s why ATF was developed.

    ATF is called out for the TM Moto too and it has a wet clutch.

     

     

  • #7726

    Chris Beebe
    Participant

    I want to thank everyone for their replies! Its all good info to think about. Seems like if I asked A question about who liked round waffles vers. square waffles we would still have an internet argument! I like round waffles BTW! Its all good and makes for some good reads! Personally I have a mechanical background and know enough about two strokes to not need to worry! It would be easier if there was a manual out there for this but I always like to know what everyone else is doing! I am new to karts but not to motorsports so its nice to have these places to ask questions and learn a little about a new subject! I will say however that my plan it to change the oil based on drive time. Racing or practice, its all the same in my book because I drive the same. So probably about every couple of trips to the track. I will even say that even though some of the info may not apply earlier, I learned some new things about different kart motors! Its all good!

  • #7733

    Donnie Leonard
    Participant

    I have a Pavesi and the oils are changed every 3 race weekends.  I tend to do more sprint racing then road racing but oil is cheap insurance to me so it gets changed often.  In the gear box I use amsoil and in the wet clutch I use Toyota WS trans fluid since I have alot of it.  And if you want your trans to shift effortlessly I highly recommend looking into getting all moving/wearing parts in the gearbox REM treated.  If you want to know more about REM treating or where to get it done http://www.taylor-race.com will be a big help.

  • #7742

    Chris Reinhardt
    Participant

    <div class=”d4p-bbp-quote-title”>Thomas Barth wrote:</div>
    Ken Shilling posted: I’ve heard the ATF is a little too thin and doesn’t have enough or the right kind of high pressure lubricants to withstand the transmission and clutch. Ken please don’t post information that is hearsay. The automatic transmission is way, way harder on oil. That’s why ATF was developed. ATF is called out for the TM Moto too and it has a wet clutch.

    <hr />

    The funny thing is, everything KZ is hearsay because there isn’t a reference manual!!!! :)

    ATF is above everything else, a hydraulic fluid.  It obviously has lubricating qualities, but there’s probably better choices out there, even for the TM….

    BTW Honda manual says:  Change the fluid at least,  every 3 races or 7.5 hrs

    Chris Reinhardt

    CR2 Motorsports

    http://www.cr2motorsports.webs.com/

    XV Racing Products

    http://www.xvengineering.com/

    ­­

  • #7750

    Jimmy McNeil
    Participant

    Some Moto-X’rs feather the clutch on track, especially a cr125. When I raced two strokes, I pulled the clutch, pinned the throttle and used the clutch to accelerate through the corners (especially if their were ruts).  I could burn up a clutch in a couple months on a bike, Ive yet to burn a cr125 clutch up on a kart. For the most part, the clutch is used on the starts only. Ill go months between oil changes and the oil still looks new, have never had trans failure and went 20 months on my last rebuild.

    BTW, prob spend 3 weekends a month at the track.

  • #7752

    Sam Zavaglia
    Participant

    Thank god I read your post Jimmy, I was ready to change the trans oil in my Stock Motos tonight after reading others.

    I only change the trans oil every 2 years when I do a bottom end rebuild. That is around 24x race meetings at about 1 hour racing each meeting.

    I use Castrol MTX which is 2 stroke trans oil for wet or dry clutch, no problems.

    Our seasons would see a low of 40F – 100F and no snow so don’t have extreme outside conditions like some parts of USA to consider condensation in the transmission. Pretty much we are like LA California conditions here.

    I’ll rest easy now.

     

  • #8452

    Thomas Barth
    Participant

     

     

  • #8453

    Thomas Barth
    Participant

    gears- and for how many hours this will last- without adding oil?</span></p>

  • #8456

    Robert Lawson
    Participant

    This is a very interesting subject. And, like most others very subjective!

    I am currently on an ICC (dry clutch) and use very lite weight motor oil in the gear case for 2 years with no issues. For 15 years (add 5-6 more on MX engines previously) I had been running ATF in my RS125 (GP bike engine). The clutch was wet and it never gave me any trouble, even with the tall 1st gear.

    No matter the type I still change it after every weekend. The ATF on a wet clutch gets dark and stinks like clutch material, can’t say it broke down at all after 1 weekend. The oil in the dry clutch looks just like it came out of the bottle but I change it anyway.

    Just 1 gear related problem in 15 years on that RS, 4th gear went out of it. BUT….that was my own fault. I had multiple ratios for all 6 gears and most of them were purchased used from bike guys. The dogs were questionable yet I talked myself into using it anyway.

    Imagine racing Grattan, in a laydown 125, with only 5 of your 6 speeds, having to shift from 3rd to 5th 3 times per lap, for 30 minutes! Tough on the ole forearms for sure, can’t explain it but we ran decent times (about 1.2 sec off our best at the time) and beat some single 250’s winning the Unlimited class. I don’t recommend this practice, if it’s truly broken it could have caused catastrophic damage. In my case it was just worn dogs……and I was pissed…..so I ran it anyway!!!!!

    Beware: All the above is just my own personal experience…….as it happened to me……….otherwise known as “hearsay” :)

    Bon’ Appetite!

    RPM

  • #8459

    Robert Lawson
    Participant

    I forgot this:

    I bought that RS brand new and never changed any of the gearbox bearings.

    ATF keeps everything super clean, I soak my chain it after each weekend too!

    Chew thoroughly!!!!

    RPM

  • #8543

    Thomas Barth
    Participant

    Good news guys! Just got an email from KZ karter in Norway. His son runs a KZ10B. They rented a engine from a well know tuner for a big race. He checked out the set up and found that he (tuner) doesn’t run any oil in gearbox!!!

    But I’m sure they must process gears or treat with a special lube prior to event.

  • #8546

    Chris Beebe
    Participant

    Are you serious?

    I say if this is true someone just has to much money to spend and I could help them out if needed!

  • #8550

    Chris Reinhardt
    Participant

    <div class=”d4p-bbp-quote-title”>Thomas Barth wrote:</div>
    Good news guys! Just got an email from KZ karter in Norway. His son runs a KZ10B. They rented a engine from a well know tuner for a big race. He checked out the set up and found that he (tuner) doesn’t run any oil in gearbox!!! But I’m sure they must process gears or treat with a special lube prior to event.

    And you believed him?

    And how do the bearings get lubricated?

    Chris Reinhardt

    CR2 Motorsports

    http://www.cr2motorsports.webs.com/

    XV Racing Products

    http://www.xvengineering.com/

    ­­

  • #8561

    Robert Lawson
    Participant

    CR,

    Don’t know about you but nothing drivers/tuners do surprises me.

    Guys,

    The lite weight oil and ATF for that matter are used (in most cases) because of their lower viscosity……it’s simply easier to turn a gearbox in thin lube. Belray gearsaver is as close to ATF as anything can be spec wise. That’s what I started on back in the day and is the sole reason I went to ATF. Let me be clear here, I was using Mobil 1 synthetic ATF. If you look into it this product is NOT available wherever Mobil 1 products are sold. Very few AP stores that carry Mobil 1 products will carry the synthetic ATF. NO Mobil fuel stations will have it, hell….they don’t even know what your talking about!!!!

    These minor changes from OEM or “Manuel suggestions” are what Tuners call “Free HP”. Understanding this you will find many more “free HP” tricks on your chassis than in your engine, no matter the classification or brand.

    The “No Lube” GB trick is not so unbelievable to me. A true test of patients if it’s not on a cassette gear case that has bearings that are quickly accessible. The now immortal King of Hocus-Pocus, Zito Maximus (aka Kenny D), has shared many of his chassis tricks of “free HP” with me over the years. Most at first sounded ridiculous, even stupid! The most outstanding in my memory was to remove one dust/dirt shield on all chassis bearings, remove all shipping grease (heavy weight lube) with a propellant cleaner of your choice (carb/brake cleaner) and replacing that lube with……well, I can’t tell you! It’s a concoction of Teflon (kinda, but not exactly) and a super fine (can’t express “super” enough here!) high speed lubricant that will not break down.

    My results were as he promised, eye opening. The stop watch tells the story and just pushing the kart afterwards was noticeably easier.

    Would this type of thing work in gear case bearings? He isn’t here to convince me so I can’t answer that but it isn’t inconceivable. I would guess, if the “tuner” in question above didn’t label the fill plug with a tag reading “NO OIL” maybe he knows something the rest of us don’t. Maybe it was shipped and purposely had no oil in it…..we don’t know that either.

    Kenny never produced a “Manual” as far as I know. But, I never considered what he had to say as Hearsay simply because it wasn’t in print or from a “Manufacture”.

    All an OEM Manuel will tell you is what they recommend for “safe operation”. Meaning, in not so many words, your OEM engine is produced in a “safe” state of tune. My RS was not manufactured by Honda Motor Corp., it is produced by HRC. A completely different entity, it’s why you can’t use RS p#’s at your local bike shop. They don’t use the same language….so to speak.

    A stock std RS, new like mine was, is a “privateer package”. MUCH safer tune than the Factory set-ups. They do this for a reason, not to slow private riders or to hog all the good stuff for the Factory supported teams but to keep privateer teams in business. Simply put, they can’t afford the maintenance schedule of Factory bits. Everyone should automatically know that you will lose reliability as you climb the ladder of mods or kits from stock std. Without those private teams the Factory teams couldn’t exist.

    Opinion directly related to testing results my friends is not hearsay. It’s fact. What makes it difficult to implement is simply whether you believe the source or not.

    There are so very few of us guys left in Karting now. Guys that are not bound by a book or a shops “Gospel”. Guys that will plow that path on their own, build it themselves. Test it, change it, test it again, toss it to the scrap, redesign it, and test it again, and again, and again.

    These are the true karting pioneers. Kenny was just one of them. Tom, god bless his aging a$$, has done more of this than any of you combined.

    I have only been at this for 30 years after Pops turned me loose to do it myself. I love development and sourcing, and testing, it keeps me thinking outside the box (Manuel)!!!!!!!

    I know, I know, it will take a week to digest this post!

    Dessert anyone????? :)

    RPM

  • #8564

    Chris Reinhardt
    Participant

    Robert, I agree with you, if Kenny said it, I would believe it, for a couple of reasons.  For starters the man had some gray matter, and most importantly, the information would have been FIRST HAND.  Ever seen a gear that came out of a gearbox with no oil in it?  It’s not pretty….

    Considering the person that posted it, lashed out to somebody else about posting hearsay, then did exactly the same thing, doesn’t really bode well…

    As far as information in a manual, if you are a decent engine builder, that’s a really good place to start with regards to how far to want to set your tolerances.  Some of the best engine builders I’ve ever met, were machinists.  They measure everything, and know what to do with + or – tolerances.  There’s nothing stopping a person from measuring everything in a motor and coming up with your own set of tolerances,  if you don’t mind breaking some eggs to make an omelet….  and Italian eggs aren’t cheap…….

    All this food talk is making me hungry, and it’s lunch time!!!!

    CR

    Chris Reinhardt

    CR2 Motorsports

    http://www.cr2motorsports.webs.com/

    XV Racing Products

    http://www.xvengineering.com/

    ­­

  • #8566

    Thomas Barth
    Participant

    And you believed him?

    Yes, I believe him!

    The other side of the pond is where all the ‘secrets’ are.

    And how do the bearings get lubricated?

    If you have done maintenance to the KZ you will find that the some of the GB bearings are sealed, some are not. The gear box shafts turn at approximately 3500 rpm. The bearings will hold up fine without lube.

    My son tells me I provided a KZ for a couple of races a few years back. No oil in gearbox. Never found out until I took engine down.

    Chris you need to get up to speed.

  • #8568

    Chris Reinhardt
    Participant

    I hear over there, they put whole tomatoes in the gearbox, after the race, they drain it and make a nice sauce with it :)……

     

    Tom Barth wrote “The other side of the pond is where all the ‘secrets’ are.”

    Hold the phone, you said there weren’t any secrets?  I quote: “all you need is to bring it up to homologation spec”.  I believe you also said they all run the same……

    Why would they put a fill and a drain plug on a transmission that doesn’t require oil?  Why would they ship them with ATF inside, and why would you specify that they require ATF?  I guess maybe if there were a factory service manual, all this wouldn’t be such a mystery…..  Or as Robert wrote “Manuel”, that’s the guy back in Italy that has all this information….

    OK, let it rip Tom, I have my boots on……

    CR

     

    Chris Reinhardt

    CR2 Motorsports

    http://www.cr2motorsports.webs.com/

    XV Racing Products

    http://www.xvengineering.com/

    ­­

  • #8573

    Greg Wright
    Participant

    Another exciting episode of the Chris and Tom show, Always good for some grins.

    Greg Wright
    Rapid Racing Inc.
    Vintage B-Stock Pilot
    "When in doubt Gas it, It won't help but it ends the suspense."

  • #8625

    Robert Lawson
    Participant

    You guys are too much! Tom is turning into Wally before our eyes!!!!!!!!!

    Tomato sauce……that’s funny dude. :)

    And Tom…..just stirin away.

    Have a good time fellas.

    RPM

  • #8648

    Carl Beavers
    Participant

    Make sure it is full before each race day and change it at the end of the season. More than that is just a waste of oil.

  • #8672

    Thomas Barth
    Participant

    and  how do the bearings get lubricated?

    Just did the bottom end on TM K9B today. I hadn’t paid much attention to the gearbox layout before I found out some tuners don’t use oil. So I looked at bearing placement and realized that the C/L of the (4) main bearings (main shaft, secondary shaft) in the box are located above the oil level screw hole. The only way that the bearings can get lube is from splash. So it appears that lubing the gears and bearings is not a big deal.

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