IS250 Manual Gearbox Flaws

[DannyM]

Hi everyone, 

New to the forum, not new to the Lexus brand. I've recently purchased a 2007 IS250 manual with 140k miles. Loving the car so far, my own one slight dislike so far being the gearbox. 

Is there an inherent issue with the synchros in the Aisin RA6 gearbox fitted in the IS250? I've seen a number of complaints for different issues with these gearboxes on US Lexus forums including crunching between gears. For me personally, I find that when I try and shift quickly from 4th to 5th or 5th to 6th gear at high rpm there is a slight crunch. If you don't rush your gear change there is no problem. I've also noticed that there is a rev hang when you clutch in. I believe this is down to the nature of drive by wire throttle and or heavy flywheel. 

Has anybody here have similar nuisances with the IS250 manual gearbox? Just trying to determine if there are inherent issues with the gearbox or if it's more my driving style I need to adapt. Clutch was just changed on the car before I bought it. Definitely not a make or break problem either way. As a full package I love the car and it's something I can live with. 

All the best,

Danny. 

 

 

[Jez. W]

With that mileage it is probably wear. Depending on what sort of life it has had. I think the more you do it the worst it will get. 

You can get some good oil treatments which help, like redline etc. I did this in an old high mileage mazda mx5 and it definitely helped and almost fully cured it unless I really rushed the gear change. 

Try a gearbox oil additive/treatment. You will notice the box will be a lot slicker. Also if it just had a recent clutch what oil did they put in the box as it needs to be the correct stuff. 

If that doesn't work you will have to be gentle or get a gearbox rebuild.... 

[DannyM]

Thanks Jez. It was done at a Toyota dealer so I'd like to assume it was the correct 75w85/90 GL5 oil. That said I don't know the details of work done as it was before I owned it. I have myself replaced clutches leaving the prop shaft in so they could've done that. 

I've never actually spoke to anyone whose used a gearbox additive so great to here you've had success with it. I wanted to change it regardless for peace of mind so I will try a synchro additive with it. I tend to do full service and fluid change anytime I buy a car regardless of history. 

Cheers for your help. 

Danny. 

 

[DannyM]

Quick update on this for anyone who's interested. Replaced both my differential and gearbox oil 2 weeks ago. Turns out my gearbox was overfilled with oil. It must have been filled from the top previously (if that's possible on these) as at least a litre came out of the fill plug when I opened it! Replaced with Motul Gear 300 and there is a night and day difference. Shifting is much smoother and 5th gear crunch at high rpm is all but cured. 

Danny. 

[Texas]

Happy day, Cheapest fix you could possibly have for a Lexus I reckon ( removing some oil!)

Thanks for coming back and posting the remedy to your problem, hopefully others may benefit if they have similar symptoms in the future.

paul m.

[AFlex]

Did you do the oil change as DIY or did you get dealer to do it?

I am a bit wary to get an Indy dealer to do it because apparently it involves refilling several times to flush all the old oil out - it's not a simple drain and refill like the engine oil...

I think this video explained it well from memory...

 

[AFlex]

Also the other factor that I think plagues ALL manual transmissions nowadays is rev hang. (Not just a Lexus problem)

This is very noticeable in the IS250 manual - quickly press the accelerator immediately after starting the engine - notice how the revs immediately rise and fall. Now wait approx 10 seconds and do the same again - notice how the revs take a long time to fall after each press of the accelerator. This makes it very hard rev match if you are in a hurry. My personal way around this is to double de-clutch which slightly reduces the problem.

If I keep my IS250 for much longer I will invest in an RR racing engine remap which I think may help with this. (I'm also considering a 3GR engine swap as an upgrade to do concurrently).

[DannyM]

I changed the gear oil myself. I personally don't see the need to flush it. If you drain the old oil shortly after a drive when it's still warm you'll get the majority of the old stuff out. I'd recommend ordering up new crush washers from the dealer for the fill and drain plug. They're not expensive, think I paid €0.50 ea and got 4 as I did the diff too. The attached video wouldn't be applicable as that's an auto transmission and they do require a bit more care when doing an oil change. The manual is just a case of fill until oil begins to trickle back out of the fill plug. The car must be level when you do this of course. I'd also recommend you open the fill plug first before the drain as good practice! That way you won't have lost all the oil out of it before you realise you can't refill it. 

I think the ETCS is the biggest culprit for the rev hang. There's a bit of a delay before it registers you've taken your foot off the accelerator on a gear change. If you've ever driven the XE10 IS200 the ETCS delay can be really noticeable in that. Not so much rev hang but delay in throttle response at certain engine loads. That said the XE10 has gen1 ETCS with cable drive throttle onto a TPS with a stepper motor throttle plate. Lexus' do use dual mass flywheels so the high inertia also contributes to the rev hang. It's taken me a long time to get used to! Would definitely agree that rev match downshift helps massively.

I'm a bit sceptical about how much the remaps can change the throttle mapping. You could potentially map it in your favour in that under certain conditions you've less error feedback and it's a bit quicker to reach its target position. You wouldn't have control over the feedback gains though which is ultimately what will drive its ability to respond quickly and accurately to changes in driver input. I'd love to see a 3GR manual swap in one. It's such a shame we didn't get a 350 in Europe. Even the US still got a bit short changed with the only option of an auto 350 too. It's understandable why Toyota didn't offer a manual option though, was never going to be a big seller.

 

[AFlex]

I think the blame for rev hang is often a bit misdirected at the DMF - try what I said next time you are in the car, and you will see there is something in the computer that kicks in after 10 seconds or so. The throttle response totally changes after first 5-10 seconds of startup, and the revs begin to fall much more slowly. I will try and record a video when I have time. Seems to me it's definitely an ECU issue (It's done to reduce emissions). Having said, it that would be worth trying deactivating ETCS to see if it helps...

Yes I would also love a 350 but the engine swap (4GR) just seems too complicated. I know there is a guy Jeff Lange on the US forums who successfully did it but he literally works for Lexus and probably has a bunch of mates to help him out. Jeff himself says that the 3GR engine is a direct drop in - don't even need to change the engine ECU.

People might say that it's better to just get a BMW 335i but I love the lexus reliability - these engines are just bulletproof and can keep going for 'spaceship' mileage, as someone very aptly put it on this forum.

Not a fan of the European cars myself - they specifically seem to cater towards corporate fleet cars where there is this 3 year useful life mindset (after which they fall apart). Absolute madness when you consider how much a car costs you in depreciation if you only ever keep it for 3 years.

 

 

 

 

 

 

[DannyM]

The ETCS does do a lot of secondary functions like idle control, traction control etc so I wouldn't be surprised if the Toyota engineers stuck something in there for emissions control. 

The swap you want to do is the 3 litre v6 from the GS300 which is the 3GR, is that correct? The 2.5 in the IS250 is the 4GR. 

I've had a couple of BMWs in the past albeit older ones but I will say they don't age well. From the interior they suffer badly from bolster tears in the drivers, seat wear on steering wheels can also cause splitting in the leather. An equivalent age and mileage Lexus won't have those issues. I still love BMWs though they are fantastic drivers cars. The BMWs can be a bit of a minefield regarding engines so you do need to be careful with which you buy and the maintenance. 

I live in Ireland and we have massive depreciation here on larger petrol engine cars and cars older than 2008 as our motor tax favours newer diesel cars and small engine petrol cars. I actually went onto the way back when web page and looked up the original for sale price of the IS250 here. Mine is a sport with the nav and sunroof and they were €60,305. For the price I paid you're talking €4,300 per year in depreciation. That is the nature of the Irish market here I don't know how the UK market fairs in comparison. The most popular cars here at the min are the likes of Hyundais as the Irish have a "new car mentality" where they prefer having a brand new reg numberplate on low spec cheaper brand cars than buying something a few years older for the same money with nicer spec. All our nice spec cars here tend to be UK imports. My IS250 was originally a Northern Irish car. 

[AFlex]

15 hours ago, DannyM said:

The swap you want to do is the 3 litre v6 from the GS300 which is the 3GR, is that correct? The 2.5 in the IS250 is the 4GR. 

Correct. Looks like the most sensible swap but would have to find out how much it would affect my insurance premium as to whether it would be worth doing.

15 hours ago, DannyM said:

For the price I paid you're talking €4,300 per year in depreciation. That is the nature of the Irish market here I don't know how the UK market fairs in comparison. The most popular cars here at the min are the likes of Hyundais as the Irish have a "new car mentality" where they prefer having a brand new reg numberplate on low spec cheaper brand cars than buying something a few years older for the same money with nicer spec. All our nice spec cars here tend to be UK imports. My IS250 was originally a Northern Irish car. 

I wasn't so much saying that the Lexus won't depreciate as much - I was saying that to perpetually own cars from 0 to 3 years and then trade for a new one is a mugs game - you will spend your entire life paying depreciation. I think this fact is lost on a lot of people because the motor industry has very successfully shifted our focus away from the list price to the "monthly PCP price". Very clever strategy, exactly the same strategy as is used with iPhones etc. If you buy a reliable car outright and keep it for 10 to 15 years you get much more for your money (I bought my IS250 Sport used for 10k and have since owned it for 7-8 years and it's still going strong. (And btw there is the same culture in the UK of preferring a brand new reg numberplate, which, being someone who is more of a 'driver', I have never fully understood)

[Pfallon2009]

On 10/23/2020 at 9:30 AM, DannyM said:

The ETCS does do a lot of secondary functions like idle control, traction control etc so I wouldn't be surprised if the Toyota engineers stuck something in there for emissions control. 

The swap you want to do is the 3 litre v6 from the GS300 which is the 3GR, is that correct? The 2.5 in the IS250 is the 4GR. 

I've had a couple of BMWs in the past albeit older ones but I will say they don't age well. From the interior they suffer badly from bolster tears in the drivers, seat wear on steering wheels can also cause splitting in the leather. An equivalent age and mileage Lexus won't have those issues. I still love BMWs though they are fantastic drivers cars. The BMWs can be a bit of a minefield regarding engines so you do need to be careful with which you buy and the maintenance. 

I live in Ireland and we have massive depreciation here on larger petrol engine cars and cars older than 2008 as our motor tax favours newer diesel cars and small engine petrol cars. I actually went onto the way back when web page and looked up the original for sale price of the IS250 here. Mine is a sport with the nav and sunroof and they were €60,305. For the price I paid you're talking €4,300 per year in depreciation. That is the nature of the Irish market here I don't know how the UK market fairs in comparison. The most popular cars here at the min are the likes of Hyundais as the Irish have a "new car mentality" where they prefer having a brand new reg numberplate on low spec cheaper brand cars than buying something a few years older for the same money with nicer spec. All our nice spec cars here tend to be UK imports. My IS250 was originally a Northern Irish car. 

Hi Danny, I'm also in Ireland and I'm looking to buy is250. Did you try the autos, there are a lot of recommendations to pick the auto over manual online. Also have you had any issue with the e10 fuel, I know Lexus has said any pre 2008 is250s are not compatible with e10 fuel. Thanks Padraig 

[DannyM]

12 hours ago, Pfallon2009 said:

Hi Danny, I'm also in Ireland and I'm looking to buy is250. Did you try the autos, there are a lot of recommendations to pick the auto over manual online. Also have you had any issue with the e10 fuel, I know Lexus has said any pre 2008 is250s are not compatible with e10 fuel. Thanks Padraig 

Hey Padraig. I never drove the auto but my own preference now having owned the manual would be an auto box. I sold my IS250 about 2 years ago for the reasons mentioned above. I had really high expectations for it which I think was ultimately the problem as the longer I owned it the more I disliked it. It's probably the one car I've owned that I never clicked with. My expectations was it would be an improved upon IS200 manual. They are certainly more refined and grown up but I felt the manual option was an afterthought by Lexus. If I was to repeat I'd 100% go auto and ideally SE-L spec and just enjoy it for a daily cruiser to waft around in.

I can't weigh in on the E10 impacts as I sold mine before it came into affect. I'd imagine you'd be relatively safe if you've went for something 08 or older that's been in continuous use. I'd be more concerned about something doing minimal mileage that has E10 sitting stagnant in the fuel system pulling in moisture. I'd start with the E10 additive then. The Wynns stuff is great. I use it in my bikes which range from newish fuel injected to old carburetted stuff. They do sit up over the winter with fuel in the tanks and have had no issues to date.

[Pfallon2009]

Ok great thanks. Ya I might stick to the auto so. I am just concerned about the auto doing the constant hunting for right gear or even dropping to too low a gear when I put power on, I don't want the thing screaming when I'm driving through streets of dublin! I am looking a cheap fun roundabout and would love a BMW 325i or something but I hear nothing but mechanical and electrical issues with everything below the 10k mark, and I don't have the skills or time to be fixing them up. 

[H3XME]

50 minutes ago, Pfallon2009 said:

Ok great thanks. Ya I might stick to the auto so. I am just concerned about the auto doing the constant hunting for right gear or even dropping to too low a gear when I put power on, I don't want the thing screaming when I'm driving through streets of dublin! I am looking a cheap fun roundabout and would love a BMW 325i or something but I hear nothing but mechanical and electrical issues with everything below the 10k mark, and I don't have the skills or time to be fixing them up. 

It won't be hunting for gears all the time. It's only a 6 speed. It's not bad like that at all. IS250 will treat you well, and they are much more suited to the auto box than manual.. they're no sports cars. Not to mention, go for a test drive mate, you'll know then.

[scudney]

Probably wants to drive it like........lol 😆🤣

[Pfallon2009]

Ok your right test drive is the only way. Thanks for the advice