gearbox oil

Discussion in 'Bay Tech Clinic' started by robmich, Oct 27, 2017.

  1. robmich

    robmich Active Member

    Messages:
    485
    Location:
    buff point
    Hi All was wondering if there is a use by date on oil i have a bottle in the garage that is nearly full i bought it 7 or 8 years ago and only topped it up but was thinking about doing a complete change this weekend there is more than enough left what do people think
    Rob
     
  2. peter915

    peter915 Active Member

    Messages:
    494
    Location:
    Sunshine coast
    It should be OK - its only heat and usage that will destroy the oil.
    I would use it.
    Should change the gearbox oil often.
     
  3. robmich

    robmich Active Member

    Messages:
    485
    Location:
    buff point
    interesting you say that all the manuals say you dont need to ,but i guess they were written a long time ago when the vehicles were a lot newer, what are your thoughts on some of the additives
    Rob
     
  4. peter915

    peter915 Active Member

    Messages:
    494
    Location:
    Sunshine coast
    You could buy all the additives available but its better and more reliable to Change the oil often.
    Remember the differential and the gearbox are combined ( transaxle) together with only a small amount of oil. No filter, no cooler.
    Next time your vehicle has just completed a long drive, duck under the bus and put your hand on the gearbox near the diff, just see how hot it gets.
    Oil is cheaper than the parts in the box
     
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  5. Grantus

    Grantus Well-Known Member

    Messages:
    13,189
    Location:
    Southern ACT
    So at what km interval do you consider to be “often”? :rolleyes:
     
  6. peter915

    peter915 Active Member

    Messages:
    494
    Location:
    Sunshine coast
    I'd do the box oil every 20k
    Like I said, its cheap, its easy to do, so its viable - bit like rotating the tires.
    It would be different if you had a filter and cooler (with a pump)( and thermostat)- then the oil would perhaps have an extended life.
     
  7. syncro

    syncro Well-Known Member

    Messages:
    8,425
    Location:
    Southern Highlands
    Unless you are driving through water the gearbox oil lasts for many years. It doesn't wear out and there is a magnet to catch the metal bits. Buy good quality and it will not be heat affected. Do not use GL5 as it corrodes the synchro rings.

    Put your finger in the box and just see the condition of it.
     
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  8. robmich

    robmich Active Member

    Messages:
    485
    Location:
    buff point
    Hi All
    replaced the gear oil today also added a tube of Nulon additive (the guy at the auto parts shop was a convincing salesman ) the old oil was a lot darker than the new stuff the magnetic sump plug didnt have many bits stuck to it ,not like the pictures of other peoples that i have seen on sites like this, the worst part of the job was getting the drain and fill plugs out, looks like some butcher had used a chisel in the past only had a short drive as ran out of time no difference that i could tell hope to get a few more Ks on it tomorrow and might drive it to work next week ,the spare parts guy said to put a couple of hundred Ks on it to get the teflon additive to stick to everything, will report back with results
    Rob
    should add i used castrol EPX 80w 90 as recommended by 1500 king many years ago
     
  9. peter915

    peter915 Active Member

    Messages:
    494
    Location:
    Sunshine coast
    Rob
    Nice one - the transaxle will love you.
    As a matter of interest and to make a point of - How much did the exercise cost you approximately ?
     
  10. robmich

    robmich Active Member

    Messages:
    485
    Location:
    buff point
    Hi Peter
    the oil cost $40 i decided not to use the old oil and the additive was another $30 took about half the day but that dosnt count as it was a labour of love
    Rob
     
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  11. Grantus

    Grantus Well-Known Member

    Messages:
    13,189
    Location:
    Southern ACT
    Well done Rob. :)

    How long since the last time it was done? :rolleyes:



    I still question as to how many others would do it, or ask for it at servicing intervals, every 20k? o_O

    Seems a very short life span for a modern gearbox lubricant, in this day and age, where some new cars boast 15k and higher engine oil changes.
     
    Last edited: Oct 28, 2017
  12. peter915

    peter915 Active Member

    Messages:
    494
    Location:
    Sunshine coast
    Ah - some of us need to take another look - it's not a gearbox

    Its a transaxle

    It has a differential inside the same box as the gearbox.

    https://en.wikipedia.org/wiki/Transaxle

    All sharing about 3.5 litres of oil (approx)

    I did a quick look on Google before - and on the first page there were at least 3 entries for manual gearboxes (stress Gearbox not Transaxles) and all three entries varied - said from 20K up to 60K depending on vehicle and driving style, etc, for oil change.

    My 100 series Toyota Landcruiser service sheet lists the oil change for both differentials and the transfer box at 20 K.
    The Gearbox is an Auto.
    The rear diff can get extremely hot, I mean real hot.!

    A mid 1980's Porsche 911 has a 915 type transaxle made in house by Porsche, a 5 speed unit.
    It comes standard with an internal oil pump and a external oil cooler.

    The 911 weighs less than a T3 and is more aerodynamic and the oil service on the Transaxle was approx 60K.

    You can spend $3K on a transaxle re-build. If spending $80 every 2 years on an oil change extends the life of the unit; isn't it worth it?
    Or is it ostrich stuff?

    Peter
     
  13. Grantus

    Grantus Well-Known Member

    Messages:
    13,189
    Location:
    Southern ACT
    I would question the quality of just a $3k transaxle re- build for a T3.....:eek:
     
  14. David H

    David H Well-Known Member

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    2,057
    Location:
    newcastle
    Change mine every 100,k. Whether it needs it or not:). Done that for the last 7 & it's the original box :D. (one bearing bad ex factory done at 105,k). Don't know what Bentley says:eek:.
    Cheers
     
    Last edited: Nov 10, 2017
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  15. Grantus

    Grantus Well-Known Member

    Messages:
    13,189
    Location:
    Southern ACT
    700k out of the original, and still going? Impressive! :)

    And just 7 oil changes? :rolleyes:

    Kinda goes against other advice being suggested........o_O
     
  16. robmich

    robmich Active Member

    Messages:
    485
    Location:
    buff point
    Hi Grant
    i changed it 8 or 9 years ago when i bought the kombi
    Rob
     
  17. syncro

    syncro Well-Known Member

    Messages:
    8,425
    Location:
    Southern Highlands
    That's because it is an off roader and subject to water contamination.

    My Beetle gearbox did 450,000 without an oil change.
     
  18. 1500king

    1500king Well-Known Member

    Messages:
    1,435
    Location:
    Adelaide, SA
    Mineral Hypoid oil is the go.. More to protect the Ring/ Pinion. GL4/GL5. 50,000km max life... VW specified "filled for life" for many...Take that with a pinch of salt..
     

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