Gear Box Oil Change

Cotswold Pete · January 14, 2014

Had a chat with my mechanic the other day, about oil change and he said the best thing to do is to have the whole lot replaced, by having all the oil sucked out of the torque converter, as this is where 60% of oil is, and it does not get replaced on a 'standard' bleed of gear box.

Is this right, and if so has anyone had the lot sucked out, and does it make any difference going to this expense.

Apparently I was told the oil in my gear box is fine, but just curious to see whether it is worth coughing up for a full clean out.

Malc · January 14, 2014

I remember reading on here somewhere that it is strongly recommended NOT to change the gearbox oil under almost any normal running circumstances. Just top-up as appropriate.

Malc

ambermarine · January 14, 2014

The gearbox oil change ( Transmission fluid) is not part of a service reccomended schedule on the LS400 Mark 4.The exception to the rule is ,towing any kind of trailer for long periods, ie; Caravan or car transporter.It is unlikely that the oil will deteriorate through normal use and it also carries properties that with constant use swell the seals within the gearbox and feed pipes through the cooling system .So the old addage applies" If it aint broke don't fix it".

PEPE · January 14, 2014

I remember reading on here somewhere that it is strongly recommended NOT to change the gearbox oil under almost any normal running circumstances. Just top-up as appropriate.

Malc

Yes, this is exactly what my indie says.

Pepe

steve2006 · January 14, 2014

I did the drain and refill on mine (2ltrs x5 times) around 3 years ago at 60,000.

No problems before but the fluid was very dark and no problems since.

I also believe that you can pump the system by removing the cooler pipe and then refilling by the same amount removed.

Opinions vary on whether or not to change the fluid/filter so at the end of the day it becomes a personal choice.

Titch LS · January 14, 2014

The LS is not like a Merc or BMTroubleyou. BMW gearboxes are "filled for life" and they DO fail. I know a colleague at work whose BMW X5 transmission fluid was never changed and her gearbox repair cost more than my car. Another friend has a 'C' class Merc and before replacing his fluid (much more difficult than on an LS), he had bad slippage and jerking from the gearbox. Common sense tells you that any ATF will not last forever. When you drain the gearbox on an LS , only 2 litres comes out. I gradually replaced mine over a period of weeks just for peace of mind. I mainly use Toyota type IV ATF, but Comma oils also make the exact same ATF which works out a fair bit cheaper. Not many people seem know that.

Keith Bowler · January 14, 2014

When I bought my LS year before last I noticed it was a little jerky when selecting neutral from drive when stationary.

My Lexus expert checked the fluid and said that it was 'dead' very dark almost black and whiff of a burnt smell about it.

It has been replaced twice now to ensure that as has been said that the torque convertor gets to see the new fluid.

I have had silky smooth gear changes since with no other signs of any problems whatsoever.

Cotswold Pete · January 15, 2014

My mechanic did say that the fluid did not look like it needed changing, just if i did the full-monty method was best.

So as the gear box is performing fine, I'll leave it at that, as I only tow my own fat butt to work everyday see no reason to worry, though a gear box going for 250K+ miles without any trouble seems to like only a Lexus is going achieve.

dian11 · January 15, 2014

I'm agree with you :)

plastic orange · January 15, 2014

I had my fluid changed when I purchased the car 4 years ago - filter too. It wasn't cheap, but then peace of mind usually isn't. Having had an auto box ( Borg Warner 35) fail in the past, I'd rather prevention than cure. It's the same with engine oil - it does degrade, hence it gets changed.

Pete

Titch LS · January 15, 2014

I agree with you.

Parrot of Doom · January 18, 2014

"Filled for life" is a marketing trick designed to reduce the service cost of a vehicle, so that fleet managers are more likely to buy said vehicle. The fluid is certainly for life, although the life of the gearbox will be reduced if the fluid isn't changed. Silly.

Gearboxes are filled with oil, oil that will, over time, degrade in quality. It really doesn't matter if it's on the schedule or not, it should be replaced periodically, just like any other vehicle fluid. Any filters and gaskets should be replaced at the same time.

Your mechanic is correct, most of the fluid will be in the torque converter, although a fair bit may be in whatever oil coolers the transmission is connected to. Another way to get it all out is simply to disconnect one of the transmission oil cooler lines and run the engine until the oil has been pumped out completely (shut the engine off once the system is empty). This is certainly a common procedure on Mercedes cars but you may want to check if it's ok to do on Lexus boxes.

FYI, when we changed the transmission fluid on my Mercedes at about 160,000 miles, it came out black as the ace of spades. The replacement fluid was bright red.

munday · January 20, 2014

If you aren't experiencing any problems LEAVE IT ALONE!

A very experienced automatic transmission specialist i know recommends you change the fluid ONLY if you know there is a problem or you have DOCUMENTED PROOF that it has been done regularly in the past.

It is COMMON to see an auto gearbox fail only a few miles after having some nice new fluid in.

cruisermark · January 20, 2014

doesnt appear be a conclusive view wether to change or not then.

Malc · January 20, 2014

I surmise that if the oil colour looks good and the gearbox performs well then it's best to just leave well alone !

That's pretty conclusive to me.

Malc

Parrot of Doom · January 20, 2014

If you aren't experiencing any problems LEAVE IT ALONE!

A very experienced automatic transmission specialist i know recommends you change the fluid ONLY if you know there is a problem or you have DOCUMENTED PROOF that it has been done regularly in the past.

It is COMMON to see an auto gearbox fail only a few miles after having some nice new fluid in.

Your experienced specialist would no doubt hold a different opinion if anyone gave the same advice when it came to engine oil.

I simply do not understand why on every other aspect of a vehicle, people recommend periodic fluid changes, but when it comes to transmission fluid, apparently there's witchcraft involved and it should never be touched. Transmission oil is subjected to extremes of temperature and degrades over time. And I do not believe that failures are common because fluid is replaced. I suggest it's more likely that the fluid was replaced in an attempt to cure a fault, or that the wrong fluid was used, or incorrect amounts of said fluid.

lexusdaduk · January 20, 2014

I checked my Fluid about 6 months ago it's red and looked fine I have no gearbox issues the car has covered 85.000 miles, Personally I think Lexus know that changing gearbox oil is a lottery it can cause damage and as gearboxes are very very expensive they shy away from it in favour of leaving alone against possible replace claim,

1 claim for a new gearbox would eradicate 20 gearbox oil fills it's simple math. History has shown that leaving alone is the best financial policy.

If lexus or any other garage could advertise a £250 fluid change into their service a schedule CONfident in the knowledge that it would cause no problems I think they would.

Had a GB oil change on my E300TD @ 62,000 it's covered a 123,000 and still running fine.

Parrot of Doom · January 20, 2014

Sorry but that's just rubbish. The idea that a periodic fluid change will damage an automatic gearbox is just complete lunacy.

Titch LS · January 20, 2014

I completely agree with Parrot of Doom. To never change your ATF is simply asking for trouble. ATF is an oil and it WILL degrade. It therefore will need changing periodically. My friend's BMTroubleyou X5 suffered a catastrophic autobox failure because she NEVER changed the fluid. Very expensive policy to follow, in my book. The first thing I did when I bought my high mileage Mk4 was to change the gearbox oil. My gearbox changes are as smooth as butter. I know It will stay that way if I don't allow the ATF to degrade. Common sense tells you that to preserve your gearbox, CHANGE YOUR ATF !!

Malc · January 21, 2014

Anyone know what the official Lexus position on this is ??

Malc

munday · January 21, 2014

If you aren't experiencing any problems LEAVE IT ALONE!

A very experienced automatic transmission specialist i know recommends you change the fluid ONLY if you know there is a problem or you have DOCUMENTED PROOF that it has been done regularly in the past.

It is COMMON to see an auto gearbox fail only a few miles after having some nice new fluid in.

Your experienced specialist would no doubt hold a different opinion if anyone gave the same advice when it came to engine oil.

I simply do not understand why on every other aspect of a vehicle, people recommend periodic fluid changes, but when it comes to transmission fluid, apparently there's witchcraft involved and it should never be touched. Transmission oil is subjected to extremes of temperature and degrades over time. And I do not believe that failures are common because fluid is replaced. I suggest it's more likely that the fluid was replaced in an attempt to cure a fault, or that the wrong fluid was used, or incorrect amounts of said fluid.

Comparing engine oil to gearbox oil is not relevant, comparing and engine to a gearbox is not relevant. There are many intricate differences that will influence and affect oil performance and degradation. Engine oil has to put up with massive sheer forces, chemical attack, massive heat and carbon buildup from the combustion process. Gearbox oil has moderate sheer stress in comparison and moderate heat. Therefore they are composed entirely differently.

How many engines have you seen fail due to a correctly done oil change? I'm guessing zero. The same CANNOT be said for gearbox oil changes.

I am very much more inclined to follow the advice of a specialist who has been in the business 20+ years and deals with a number of gearboxes each and every day.

Notice how I stated not to change it if you DO NOT have DOCUMENTED HISTORY of it being replaced periodically in the past. If you know its been done at 60k and 120k, sure do it at 200k. However, if you're at 150k with no history of it being done, don't touch it.

EDIT: My gearchanges are smooth as butter too, 218k and no gearbox oil change.

Cotswold Pete · January 21, 2014

Seems like a bit of a hornet's nest here.

Gear changes are fine in my 400, though some people on this forum say the 430 and 460 are smoother, so I suspect my ATF is fine, but cannot see that changing it will in anyway will cause a problem.

I assume a gear box is not subject to extreme heat and pressure of an engine, but the ATF will get slowly contaminated as minute metal wear of the gear box means oil picks it up. I understand the gear box has magnets in the pan to attract the fine particles away from the moving parts, so this also helps (I guess).

My previous Mk2 had rather dirty looking ATF (187K on clock) and it did seem to be a little less smooth than Mk4, but then maybe the Mk4 has slightly smoother action. Certainly compared to Omega I had with 180K on clock, with not ATF change, the LS is 1000 times smoother.

Parrot of Doom · January 21, 2014