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REVIEW - ATF in Gearbox

Discussion in 'Norton Commando Motorcycles (Classic)' started by 1up3down, Apr 2, 2019.

  1. 1up3down

    1up3down

    Joined:
    Jan 12, 2011
    After reading Comnoz's post a while about about him running with ATF in the gearbox for many thousands of miles touring with his wife and luggage I thought I would try it out.

    I like it. Finding a gear or neutral is immediate with just a snick, no drag or slight stick compared to regular weight gear oil. Using the gearbox is actually a pleasure now!

    Thanks Jim!
     
  2. Lineslinger

    Lineslinger VIP MEMBER

    Joined:
    Feb 26, 2017
    Mileage during test? Heat?
    Interested...
     
  3. lazyeye6

    lazyeye6 VIP MEMBER

    Joined:
    Feb 28, 2014
    Yes, how is it after 1000 miles?
     
  4. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    What about longterm gearbox wear with such a thin weight lube? Seems factory spec EP90 has a long history of gearbox durability, no?
     
  5. dynodave

    dynodave

    Joined:
    May 28, 2003
    I don't have any strong opposition to using ATF in the gearbox.
    The oil's duty is to lube and cool the gears and bearings and bushings.
    The oil selection I doubt does little to prevent the impact damage and crazing of the gear faces caused by the pounding of the heavy big twin against the antiquated design. In my mind, this is the biggest problem.
    I have enjoyed the use of the synthetic 75W-90 both Mobile 1 and Valvoline SYNpower 75W-90. These give slick gear selection even at 15-25 deg F. Not that I run the bike much at those temps any more. Conventional weights feel like stiff molasses.
    [​IMG]
     
    nortriubuell likes this.
  6. ludwig

    ludwig

    Joined:
    Aug 30, 2006
    I know Mercedes Benz ( and others ? ) used ATF in their manual gearboxes , but then , they have no primary reduction , so they spin much faster .
    If you want to be nice to your gearbox sprockets , install a belt drive with the lightest possible clutch , and choose a ratio that speeds up the box a little ..
     
    Last edited: Apr 3, 2019
  7. ashman

    ashman

    Joined:
    Jul 11, 2010
    I have always used the Hypoyd gear box oil all my Norton's life, I still have very light gear changes and a light click to netrual, gear box was rebuild back in 1979 from the dreaded lay shaft bearing and replaced the kickstart pawl 4 times and the only real wear on one gear was the kickstart gear where the pawl locks in for kicking, it was replace a very long time ago all bushes were replaced in 79 and are still inside, on my lay shaft the bearing was replaced with a tapper roller bearing back in 79 this bearing at the time was called the quick change bearing that the racers used in the days for quick changing gear ratios, this bearing is still inside my box, I have never had any oil leak from the kickstart shaft and shafts have never been shimed, so I think I will stick to my Hypoyd gear box oil, its been working well for me and all oil level have been messured by the reconmended level in my workshop manual.
    In my younger youth days my gear box copped a hiding from doing burn outs to very hard reving between gear changes, my lay shaft bearing blew right on 10,000 miles and blew when I put it into gear when leaving home and the new quick change bearing was given to me all though years ago.
    My gearbox has well over 160,000 miles on it and its still changes sweetly from the first day I brought my Norton new, so the Hypoyd GB oil must be doing its job, but I wonder if the tranny oil would have done the same but I am not going to find out I stick with what works for me.

    Ashley
     
    KiwiNeill, XTINCT and Tornado like this.
  8. XTINCT

    XTINCT VIP MEMBER

    Joined:
    Jan 10, 2012
    I won't criticize anyone here for trying something different, as I have gleaned a great deal of worthwhile knowlwdge from the contributors on this forum (you know who you are), and I do appreciate it.
    Except for extreme conditions, (racing?) I can't help thinking that this is a case of "In search of the non-existant problem".
    "Ain't broke, don't fix it " also comes to mind.
     
    concours likes this.
  9. marinatlas

    marinatlas

    Joined:
    Nov 4, 2007
    Hi, Ashley , what kind of taper roller bearing did you fit on your layshaft , to replace the 6203 ? as it should be 17x40x12, and the only one I can found right now in my book is the HR 30203 J which is 17x40x13.25 ........? or was it inside the kickstart to replace the bronze bush ??
     
    Last edited: Apr 4, 2019
  10. robs ss

    robs ss VIP MEMBER

    Joined:
    Aug 16, 2016
    Hi Ash - you've got to go with what works for you!

    The term Hypoid actually refers to a particular bevel gear design where the shafts are offset from each other (eg: some differentials) meaning that there is a lot of sliding happening during contact between teeth.
    Hypoid gear oils typically have a high sulphur content - giving it that "particular" smell (gut churning if the oil is burnt from overheating).
    It is also good for helical gears as they also experience sliding on the tooth contact patch.
    That was the design intent for the oil but... as I said above - whatever works for you.

    BTW - isn't it great to have some cooler weather? - Autumn is finally here.
    Cheers
    Rob
     
  11. ashman

    ashman

    Joined:
    Jul 11, 2010
    To tell you the truth I couldn't tell you as this bearing was given to me way back in 1979 I was down Sydney at the time and I went into this motorcycle shop that dealt in race motorcycles and caferacers, building race bike and spare parts, I told the owner who was a young bloke about my lay shaft bearing blowing on my Commando and he pulled this bearing out of the box and said this is what the racers are using so they can change lay shaft gears and lay shaft without pulling the gears off the main shaft, well thats what he told me and he gave me the new bearing and its been in there ever since, that was 40 years ago I was 20 at the time, so remembering the numbers or any other markings on the bearings you are asking a lot lol to many brain cells are gown now from my bad habits of youth from smoking puff and drinking etc., I have had no reason to go that far into my gearbox since the bearing has been in there.
    I say that shop be long gone now but I haven't been down to Sydney for a long long time.

    Ashley
     
  12. ashman

    ashman

    Joined:
    Jul 11, 2010
    Hi Rob
    When I brought my Norton new back in 1976 and got the books with my new bike it had all the imfo for what grade oil to use in the bike and the gearbox oil that was reconmended was 90 grade Hypoid gearbox oil, it even reconmended using GTX motor oil, might have been good in Pommy land but was a terriable oil for our hot climate and after a few months of using it and running hot I changed to Pennzoil straight 50 racing oil and added a oil cooler and had no more problems with running hot, but I had no problems with the gearbox oil and to this day my bike still shifts like it done since new, last time I replaced my kickstart pawl all the gears I inspected looked all good with no sign of wear and tear, but since I replaced the kickstart gear where the pawl sits I haven't been back into my gearbox and thats been about 10 years ago or more.
    Am loving my time on the bikes at the moment, Autumn is a great time of year but still can't wait till the temps drop even more, my Norton loves the cold, my plans in getting up your way has been put back, fixing up another member here Alans Norton so many oil leaks to fix but only started today and so far have fixed 5 major oil leaks and tomorrow got the oil tank to look at but so far only looks like the oil lines need fixing no oil leaking from the oil tank so will keep my fingers crossed and putting in a reed valve from the breather.
    Talk to you soon Rob enjoy our chats.

    Ashley
     
  13. kommando

    kommando

    Joined:
    May 7, 2005
    Are you sure it was a taper roller and not just a roller bearing, the std roller replacement allows the layshaft and gears to be taken out as the rollers and inner race are normally on the layshaft and the outer race in the case, the rollers slip easily into and out of the other race hence the need for shimming if the endfloat is excessive.
     
    concours likes this.
  14. ashman

    ashman

    Joined:
    Jul 11, 2010
    No it was a taper roller bearing and the inner race stays on the layshaft when pulled out to change the gears.

    Ashley
     
  15. cyclegeezer

    cyclegeezer

    Joined:
    Jul 15, 2010
    How do you set the taper preload?
     
  16. ashman

    ashman

    Joined:
    Jul 11, 2010
    Like I have said its been 40 years ago since I put this bearing inside the box so remembering how I set the preload and all is asking a lot to remember everything I did to this box, I can picture the bearing in my memory and it was a $20 bearing at the time but what I did when installing it well all I can remember is a lot of balls and bits of old bearing laying on the bottom of my GB from the old blown bearing and replacing a few bushes but other than that its a long time ago, it was also my first gearbox build and was learning as I went.
    I have rebuilt a few other Norton gearboxes over the years but have never used another bearing like it, the other gearbox rebuilds the owners brought all replacement parts for the rebuild, I just pulled them down and told them what was needed and reassembled them, I have done about 5 gearbox rebuilds the last one about 3 years ago.

    Ashley
     
  17. bill

    bill

    Joined:
    Jun 1, 2003
    i don't believe a tapered roller would work worth a #### there. the pressure on the gears trying to separate would put a LOT of pressure on the taper forcing the layshaft towards the kick start shaft and first gear.
     
  18. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Maybe this was a trype of SuperBlend bearing, with slight tapering at ends of each roller to allow shaft bending?

    Anyways, we have not yet heard Mr. Ashman's story of the day the layshaft bearing exploded.....waiting with bated breath over here.....
     
  19. ashman

    ashman

    Joined:
    Jul 11, 2010
    Well I am not going to pull my gearbox down to find out as its been working fine all those years, its been in there for 40 years now and my gear changes are nice and smooth and only slight movement in the kicker to not worry about.

    Ashley
     
  20. ashman

    ashman

    Joined:
    Jul 11, 2010
    Not really much to tell brought my Norton new at the age of 17 years old first road bike but have been riding dirt bikes for a few years after leaving school, being young and no brains my Norton copped a hiding doing burn outs and high revs through the gears the usual stuff young fools did in them days, right on 10,000 miles I was leaving my Grandmothers place where I lived at the time, I started work early in the mornings so I pushed the bike out to the front curve to start it so I didn't shake the house down, fired it up and went to put it into gear and then there was a big bang, then nothing, thinking well thats a good start to the day, motor still running but no gears, so pushed back under the house, my Norton was my only transport at the time so a good reason to take the day off and to investigate, within a hour or so later had the gearbox apart, what a mess but only bearing damage lucky.
    When I think back about it could have been worst could have happen on the way to work in peak hour up the middle of traffic, very inpatient in them days, it was a Friday when it happen and next day I was heading down to Sydney 600 miles away with a mate we were down there for a week and thats where I was given the bearing, after retuning put the gearbox back together and its still going after all those years.
    But I do remember the guy who gave me the bearing all he said was this is a quick change layshaft bearing and the mate that was with me has long gone from this earth.
    The reason we went to Sydney NSW was my mate was buying a Nitrous Oxide kit for his car as they were not allowed to be sold and band in our state, young and silly lol.
    This was the days before the inter net.

    Ashley
     
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