Gearbox Oil

[Lexiguy]

Hi guys

I have just been watching High Peak Autos on YouTube and Matthew Goodwin appears to firmly believe that changing the gearbox oil is essential maintenance that is rarely done. 

Matt says that invariably the old oil has deteriorated and is no longer lubricating and protecting as it should. He adds that it is a cheap job to have done.

My questions are:

Has anyone changed their gearbox oil or had it changed?

Does it need doing and why isn't it on the Lexus service schedule?

Is it the same as when I have changed gearbox oil previously there has been a drain plug at the bottom and a second one higher up which indicates when it is full by allowing any excess to run out.

I presume no special tools are required, just 2 plug washers and adequate gearbox oil.

My car is in at Lexus Leeds for service in 3 weeks and wonder if it would be good to get it carried out at the same time.

Thanks, Anthony 

[PCM]

I'm not sure anyone knows...

Some say never and others say, yes.

Had mine done back in the day and I did feel it made a difference.

It's probably a similar argument to that of premium fuel?! 

[Lexiguy]

Hi Piers

You are right, opinion on the subject appears divided so I was hoping that some clever bods on here have 1st hand experience of the Lexus auto box and can give me the benefit of their expertise!

Thanks, Anthony 

[Malc1]

my indy would never change the oil completely ......  the only effort he would " allow " was a partial drain and refill and that was a few years back and all was then and is still well with my gearbox ( I believe ) and I could not then, nor now, appreciate any perceptible changes in operational "feeling"

and I think I read somewhere that on the Ls400 box it's done at 130k miles ?

Maybe it's an old wives tale about complete draining, flushing and re-filling BUT I do remember somewhere on here, way back, about replacing the filter too, ensuring that all and any crud is also removed ..............  why there should be any of that in there I don't know 

BUT the job for complete 100% is to also change .  or at least clean ....  that filter too .......... I was reading 

Good luck !

Malc

[wharfhouse]

Not a Lexus, but in the mid 1990s I bought a new E39 BMW 528i Auto. This also had the lifetime fill gearbox. I kept it for 10 years and did 210K miles in it. It LED quite a hard life including high speed runs across Europe. Always serviced by BMW and the auto box oil was never changed. The auto box was still working as well as when it was new when I finally traded it in. At the time there was the same debate on the E39 forums about the lifetime fill. In the US in particular some owners had run over 300k miles with no change in the gearbox oil. Others had changed the oil and then suffered issues... From what I have read the consensus seems to be that the lifetime fill is valid (assuming normal driving) for a few hundred thousand miles but if you do want to change it then do it early and regularly to avoid issues of debris getting moved into the small channels. I also believe that regular use of a car helps reliability enormously - if a car sits around week to week without any use, then that seems to result in more issues too.

The issue with a lot of this debate is that people stop reporting on cars that are in the 200k or 300k mileage on these sorts of forums and so we don't really get a full picture of when gearboxes are failing with the lifetime fill and even if we did whether the failure was something that change in fluid would have made any difference to. I also don't believe a lot of the YouTubers (especially in the US) going on about changing oils - in the US many still recommend changing engine oil every few thousand miles...! - by the way my 528 also just had scheduled engine oil changes too, nothing more, and the engine was running sweet as a nut at 200K miles.

Just my 2-penny worth of experience.

[royoftherovers]

2 hours ago, PCM said:

I'm not sure anyone knows...

Some say never and others say, yes.

Had mine done back in the day and I did feel it made a difference.

It's probably a similar argument to that of premium fuel?! 

Once again Piers you are correct.

The questions posed by Ant can best be answered by Lexus UK or by Colin B via this Forum.

Answers provided by Members here are likely to be mere opinions.

[royoftherovers]

8 minutes ago, wharfhouse said:

Not a Lexus, but in the mid 1990s I bought a new E39 BMW 528i Auto. This also had the lifetime fill gearbox. I kept it for 10 years and did 210K miles in it. It led quite a hard life including high speed runs across Europe. Always serviced by BMW and the auto box oil was never changed. The auto box was still working as well as when it was new when I finally traded it in. At the time there was the same debate on the E39 forums about the lifetime fill. In the US in particular some owners had run over 300k miles with no change in the gearbox oil. Others had changed the oil and then suffered issues... From what I have read the consensus seems to be that the lifetime fill is valid (assuming normal driving) for a few hundred thousand miles but if you do want to change it then do it early and regularly to avoid issues of debris getting moved into the small channels. I also believe that regular use of a car helps reliability enormously - if a car sits around week to week without any use, then that seems to result in more issues too.

The issue with a lot of this debate is that people stop reporting on cars that are in the 200k or 300k mileage on these sorts of forums and so we don't really get a full picture of when gearboxes are failing with the lifetime fill and even if we did whether the failure was something that change in fluid would have made any difference to. I also don't believe a lot of the YouTubers (especially in the US) going on about changing oils - in the US many still recommend changing engine oil every few thousand miles...! - by the way my 528 also just had scheduled engine oil changes too, nothing more, and the engine was running sweet as a nut at 200K miles.

Just my 2-penny worth of experience.

Just to add to your two penny worth Phil.

"Life time fill " was defined by the original Honestjohn (Peter Lorimer) in the DT in the 70`s to mean "for the lifetime of the production run of the current model" which was typically around 7 years.

An average of 12,000 miles annually LED to 84,000 miles and owners never kept their cars for that long. But successive owners (BUYERS AND SELLERS) latched onto the term "Life time fill" as it enabled them to sell their vehicles as the buyer was LED to believe it would enable them to minimise their maintenance costs.

Your BMW experience is not untypical and needs to be admired.

On the otherhand my 20 year old Merc has covered 260,000 miles and had its Transmission oil changed every 40,000 miles. It has a full (Merc and Indy )  Service history.I have noticed a significant improvement following each change, noticeably from 2nd into first. The Transmission has otherwise been faultless throughout its lifetime.

In short, my advice would be  "if it works don`t change it and do change if you notice any subtle change." Every 100,000 or 10 years miles might otherwise be an apporopriate point at which to review the performance of one`s transmission.

[wharfhouse]

15 minutes ago, royoftherovers said:

Just to add to your two penny worth Phil.

"Life time fill " was defined by the original Honestjohn (Peter Lorimer) in the DT in the 70`s to mean "for the lifetime of the production run of the current model" which was typically around 7 years.

An average of 12,000 miles annually led to 84,000 miles and owners never kept their cars for that long. But successive owners (BUYERS AND SELLERS) latched onto the term "Life time fill" as it enabled them to sell their vehicles as the buyer was led to believe it would enable them to minimise their maintenance costs.

Your BMW experience is not untypical and needs to be admired.

On the otherhand my 20 year old Merc has covered 260,000 miles and had its Transmission oil changed every 40,000 miles. It has a full (Merc and Indy )  Service history.I have noticed a significant improvement following each change, noticeably from 2nd into first. The Transmission has otherwise been faultless throughout its lifetime.

In short, my advice would be  "if it works don`t change it and do change if you notice any subtle change." Every 100,000 or 10 years miles might otherwise be an apporopriate point at which to review the performance of one`s transmission.

As you say - a lot of speculation as to what is the right or wrong thing to do...

[Neil E]

I say change it if it's old or high mileage. They seem to run fine without changing the oil for a very long time but why would you not change it for some nice fresh Aisin fluid at some point? If it's a dirty brown colour and not a nice shade of red, that's perhaps a good indicator.

[Glyn Jennings]

11 minutes ago, Neil E said:

I say change it if it's old or high mileage. They seem to run fine without changing the oil for a very long time but why would you not change it for some nice fresh Aisin fluid at some point? If it's a dirty brown colour and not a nice shade of red, that's perhaps a good indicator.

The service book only goes up to 10 years or 150,000 miles saying to inspect only. If it had extended past this I am sure it would suggest changing the diff and transmission oil at some point. I think from seeing various posts on  other forums the important bit is all the old oil and any residue is flushed out properly.

[wharfhouse]

45 minutes ago, Glyn Jennings said:

The service book only goes up to 10 years or 150,000 miles saying to inspect only. If it had extended past this I am sure it would suggest changing the diff and transmission oil at some point. I think from seeing various posts on  other forums the important bit is all the old oil and any residue is flushed out properly.

Therein lies the issue - if during the drain/flush any debris gets lodged in the very small hydraulic passages of the auto box it will have issues possibly requiring much more expensive repair. That's why the consensus seems to be either a) do not change if very high milage unless problems are experienced (in which case you have nothing to lose) or b) change early and regularly as Roy has done with his Merc. I have followed these debates since my E39 BMW 528i days and from what I can conclude never changing the oil does not seem to pose any more risk than changing the oil at a high mileage - in fact there seemed to be less reported issues leaving well alone (with cars doing 200k/300k miles happily with no change) compared to issues reported from those who changed the oil - of course that may also be down to the skills of the person doing the change too... Changing the oil regularly at perhaps every 50k miles (assuming you have had the car from nearly new) seems to be the safest bet if you want to do oil changes and run the car to 200/300K miles.

[ColinBarber]

There is a lot of speculation about transmission fluid and what lifetime means. Is it 70k, 120k, 200k?

If your vehicle is under a warranty, be that original manufacturer's warranty or an extended/supplementary warranty such as Relax, then as per the service schedule that you need to adhere to you don't need to replace the fluid if you are on the normal schedule, only inspect every 4 to 6 years. If you are on the severe schedule (a lot of towing, using vehicle as taxi etc), then fluid should be changed every 60k miles/6 years. Once you are out of warranty then just because Lexus have stated it is lifetime doesn't mean you have any comeback if the lack of change causes a problem.

The 'lifetime' fluid situation seems to have come about for two reasons. One, it was a bit of an arms race with each manufacturer claiming longer and longer times between replacement and therefore running costs of the vehicle is cheaper than the competition. Two, removing the possibility of oxygen, dirt, moisture or the wrong fluid being introduced or incorrect fluid level actually improves transmission reliability over allowing regular fluid changes.

You have three main ways to change the fluid:

1. a pan drain and refill is the safest but only removes about 1/5 of the total fluid within the transmission, so you either need to repeat multiple times (but never fully replace everything, just dilute) or just do it once every 20k miles to maintain a freshness to the fluid. If you just drain the pan into a measuring container, then you could just replace with the exact amount of fluid without going through checking the level. If you drop the pan and change the filter then you definitely want to check the level.
2. drain the pan as above then use the transmission's pump to pump out fluid via the transmission cooler lines, 0.5 litre at a time and refill until you start to get clean fresh fluid coming out which would replace nearly all the fluid.
3. Use an external flush machine - which may use too much pressure or reverse flush and stir up dirt that people have commented on. I'd only consider this if you have transmission issues and as a last attempt to fix things before having to resort to a transmission rebuild.

 

7 hours ago, Lexiguy said:

I presume no special tools are required, just 2 plug washers and adequate gearbox oil.

 

No special tools but there is a procedure that needs to be followed to check the level, including putting the vehicle into a special mode that will tell you when the fluid is within the correct 10 deg temperature range then checking the level with the engine running.

 

As to whether you should or shouldn't do it. The only Lexus I'd 100% recommend it would be for the series I RX300 with the 4 speed transmission, as the clutch material seems to wear away and contaminate/clog the transmission so a fluid change and/or external filter is a good idea. Otherwise there is no question that the transmissions get a bit slower and jerky over time, valves can start to stick which fresh detergents can help with - these transmissions can still carry on working for 200k+ miles but if you want optimum then consider doing a fluid change.

Personally if I had a Lexus that I planned to keep I would do a pan drain once it was 10 years old and then every 20k miles, only using the recommended Toyota fluid.

[royoftherovers]

1 hour ago, ColinBarber said:

There is a lot of speculation about transmission fluid and what lifetime means. Is it 70k, 120k, 200k?

If your vehicle is under a warranty, be that original manufacturer's warranty or an extended/supplementary warranty such as Relax, then as per the service schedule that you need to adhere to you don't need to replace the fluid if you are on the normal schedule, only inspect every 4 to 6 years. If you are on the severe schedule (a lot of towing, using vehicle as taxi etc), then fluid should be changed every 60k miles/6 years. Once you are out of warranty then just because Lexus have stated it is lifetime doesn't mean you have any comeback if the lack of change causes a problem.

The 'lifetime' fluid situation seems to have come about for two reasons. One, it was a bit of an arms race with each manufacturer claiming longer and longer times between replacement and therefore running costs of the vehicle is cheaper than the competition. Two, removing the possibility of oxygen, dirt, moisture or the wrong fluid being introduced or incorrect fluid level actually improves transmission reliability over allowing regular fluid changes.

You have three main ways to change the fluid:

1. a pan drain and refill is the safest but only removes about 1/5 of the total fluid within the transmission, so you either need to repeat multiple times (but never fully replace everything, just dilute) or just do it once every 20k miles to maintain a freshness to the fluid. If you just drain the pan into a measuring container, then you could just replace with the exact amount of fluid without going through checking the level. If you drop the pan and change the filter then you definitely want to check the level.
2. drain the pan as above then use the transmission's pump to pump out fluid via the transmission cooler lines, 0.5 litre at a time and refill until you start to get clean fresh fluid coming out which would replace nearly all the fluid.
3. Use an external flush machine - which may use too much pressure or reverse flush and stir up dirt that people have commented on. I'd only consider this if you have transmission issues and as a last attempt to fix things before having to resort to a transmission rebuild.

 

 

No special tools but there is a procedure that needs to be followed to check the level, including putting the vehicle into a special mode that will tell you when the fluid is within the correct 10 deg temperature range then checking the level with the engine running.

 

As to whether you should or shouldn't do it. The only Lexus I'd 100% recommend it would be for the series I RX300 with the 4 speed transmission, as the clutch material seems to wear away and contaminate/clog the transmission so a fluid change and/or external filter is a good idea. Otherwise there is no question that the transmissions get a bit slower and jerky over time, valves can start to stick which fresh detergents can help with - these transmissions can still carry on working for 200k+ miles but if you want optimum then consider doing a fluid change.

Personally if I had a Lexus that I planned to keep I would do a pan drain once it was 10 years old and then every 20k miles, only using the recommended Toyota fluid.

Many thanks Colin.

[Lexiguy]

1 hour ago, ColinBarber said:

There is a lot of speculation about transmission fluid and what lifetime means. Is it 70k, 120k, 200k?

Hi Colin

Thanks for that comprehensive appraisal of the gearbox oil change question and your explanation of different gearbox oil changes. 

I will email Jordan Robinson the service manager at Lexus Leeds and give him the information you kindly supplied and they can price up the cost of oil, filter, sump gasket and labour cost for the job.

Kind regards, Anthony 

[Malc1]

I think I was reading that these sump gaskets are non-sacrificial ..... in that they are simply cleaned off and re-used

This may not apply to all models tho' of course !

Malc

[Malc1]

2 minutes ago, Malc1 said:

these sump gaskets are non-sacrificial

sorry I meant the filter being clean-uppable !

Malc

[cdmaskell]

A very detailed thread, explaining the do’s and don’t of changing oil.  Am I being too simplistic?  Oil gets hot, contaminated and deteriorates.  Is it any different to regular changes of brake fluid, coolant and diff etc. All can have problems if not carried correctly.  It can only be beneficial.

 

[Lexiguy]

I have Emailed Jordan at Lexus Leeds and it will be interesting to hear his take on it! I will left you know.

Anthony

[ColinBarber]

4 minutes ago, cdmaskell said:

Oil gets hot, contaminated and deteriorates

Yes, although ATF doesn't really get contaminated as it is within a sealed system and under less frictional stress compared to gear oil.

The main reason brake fluid is changed is because it is hydroscopic and will rust the brake lines if not changed periodically - this isn't an issue for ATF.

 

59 minutes ago, Malc1 said:

sorry I meant the filter being clean-uppable !

for the 6-speed transmission in the face-lift SC430 it uses a foam filter inside a plastic housing - you cannot really clean and reuse it.

[cdmaskell]

Colin, completely away from g/ box oil.   I understand why b/fluid is changed. The hygroscopic effect is also caused by fluid boiling and causing a void in the fluid line.  Mind you cannot be a problem on a Lexus as the don’t generate much heat.

[ColinBarber]

7 minutes ago, cdmaskell said:

Mind you cannot be a problem on a Lexus as the don’t generate much heat.

depends how you drive it I guess 😉

[cdmaskell]

Colin. Please excuse my curiosity of your name. Are you related to Charlie Barber. Ex Barber Transport  Hackbridge? 

[ColinBarber]

1 hour ago, cdmaskell said:

Colin. Please excuse my curiosity of your name. Are you related to Charlie Barber. Ex Barber Transport  Hackbridge? 

Nope, not that I'm aware of.

[cdmaskell]

Sorry for the intrusion.

[Lexiguy]

Hi guys

Thanks for all the contributions made to this thread, which has formed a more balanced approach to this job.

Despite not receiving any clarification from Lexus yet, I think no change point is erroneous as contamination, ingress, or leaks are always possible, especially when a car has done 100k or is 15+ years old.

How could the above problems be known about and corrected without changing the oil?

Thanks, Anthony