LS430 (2003) rough downshift

[Abid221]

Hello

I've noticed on occasions that my LS430 (2003 - pre Face-lift) down shifts from 2nd to 1st roughly. Meaning I can feel in downshifting. It doesn't do it all the time though. 

I, 95% of the time drive locally school runs Asda etc. Not sire of this is relevant. 

Up shift is smooth and I don't even notice changes. 

Is it one foot in the grave for my gearbox? Time to look for a new car?? Hope not. 😞

Previous owner did mention that he'd flushed and replaced oil but didn't check. 

Any assistance would be welcomed. 

[GrahamG]

Adam, how many miles on the car?

Your car will have a gearbox dipstick so start there. Healthy ATF oil will have a degree of redness, any redness you can detect against the metal of the dipstick is good. Old burnt oil will be black. 

[GrahamG]

Are you aware that the ATF is cooled via a small radiator within the bottom of the main engine cooling radiator? If the water mixes with the ATF your gearbox is lost. There have been instances where early diagnosis arising from the gearbox misbehaving have saved the day wirh a replacement radiator.

My own action would be to get the car without delay to a Lexus main agent or an automatic transmission specialist.

Many makes suffer from this potential problem so it is well known.

[Abid221]

17 minutes ago, GrahamG said:

Are you aware that the ATF is cooled via a small radiator within the bottom of the main engine cooling radiator? If the water mixes with the ATF your gearbox is lost. There have been instances where early diagnosis arising from the gearbox misbehaving have saved the day wirh a replacement radiator.

My own action would be to get the car without delay to a Lexus main agent or an automatic transmission specialist.

Many makes suffer from this potential problem so it is well known.

Graham G

Fortunately the previous owner had installed an external radiator (pictured). Dont know if it's doing its function though. 

 

There doesn't seem to be any water in the oil when I checked the oil level. Mind you the oil was brownish with very slight signs of redness. So brown with a very slight hind of red. But you'd probably have to stare at it to see the read. 

Also not sure where the level of oil should be. When I checked just now (hot engine) its level was just above the first level indicator indent. 

The car has been looked after. It's currently at 180k mileage. 

I've attached some pictures. 

[cruisermark]

Well given the 2 factors stated above, mileage and colour being brown I would spend some money on a gearbox oil change and take it from there.

[GrahamG]

Let us be optimistic and say the external rad is doing its job and if we read  brown for red then that ATF is healthy, it is certainly not black.

I will leave you to compare the dipstick reading with your manual but do not be tempted to throw in more fluid just for luck because the level is important. I do not see that level being responsible for your problem.

I have no further advice but hope an adjustment or new solenoid might be all you need. Worth an expert opinion surely.

Good luck and let us know how you get on.

[Malc]

maybe a simple enough oil change, well as much as can be changed in one go .........  might give you a smoother drive

Malc

[steve2006]

This is for the earlier LS but may help with a flush or partial fluid change.

http://www.lexls.com/tutorials/transmission/

The transmission fluid doesn’t just do the hydraulic functions inside the transmission but also provides critical cooling and lubrication. It is therefore very important to ensure the fluid is fresh and of the correct type specification (Toyota TypeIV). If the fluid is past its best it can cause gumming up of the valves and shift solenoids.

[royoftherovers]

3 hours ago, cruisermark said:

Well given the 2 factors stated above, mileage and colour being brown I would spend some money on a gearbox oil change and take it from there.

That`s what solved the identical problem I had in my W210 Merc.

[jonthetourist]

36 minutes ago, steve2006 said:

 

The transmission fluid doesn’t just do the hydraulic functions inside the transmission but also provides critical cooling and lubrication. It is therefore very important to ensure the fluid is fresh and of the correct type specification (Toyota TypeIV). If the fluid is past its best it can cause gumming up of the valves and shift solenoids.

When I took mine in for service last week there was another 430 in Osaka. They said at some point someone had put the wrong fluid in the trans, and it was causing problems with the solenoids.

[BachelorDays]

Just to double check on the basics - you'll get the correct oil level when the engine is running, car is hot (at least half an hour of running) and you take a few readings (three or so).

Brown and smelling burnt or looking lumpy is the really bad sign. Smelling oily and looking like a smooth fluid is good, specially if the oil level is also at the right level.

If the car has had a fluid change in the last 50k miles then another fluid change will probably do good. If it's been longer than that just be careful the change doesn't cause more harm than good. Wouldn't do a flush in this case anyway.

Finally, do take a look at the MAF as well. It could be the original and at 180k may well be causing issues.

[Abid221]

39 minutes ago, BachelorDays said:

Just to double check on the basics - you'll get the correct oil level when the engine is running, car is hot (at least half an hour of running) and you take a few readings (three or so).

Brown and smelling burnt or looking lumpy is the really bad sign. Smelling oily and looking like a smooth fluid is good, specially if the oil level is also at the right level.

If the car has had a fluid change in the last 50k miles then another fluid change will probably do good. If it's been longer than that just be careful the change doesn't cause more harm than good. Wouldn't do a flush in this case anyway.

Finally, do take a look at the MAF as well. It could be the original and at 180k may well be causing issues.

Hi BarchelorDays

What if the oil smells oily and is smooth but its brown? 

Does the oil have to be red? 

And also is changing the oil a big job.? I sure can't afford to go to the stealers for sure. 

[Tinonline]

You need to get this checked and a good garage will cope at not too many £’s.

Gearbox oil has to be red.

Engine oil clear light see through light tan. If new almost too clear to see.

Rough changes from time to time are normal when you catch the system at the wrong speed/time particularly on deceleration. It’s called catching the gearbox out.

But again, gearbox oil should be red and not smell bad even if it’s old. 

[BachelorDays]

12 hours ago, Abid221 said:

Hi BarchelorDays

What if the oil smells oily and is smooth but its brown? 

Does the oil have to be red? 

And also is changing the oil a big job.? I sure can't afford to go to the stealers for sure. 

I don't think you've got a real issue with the gearbox. If the fluid level is good you should be fine until the next service and discuss the fluid change at that time. Any decent garage doing your car service will handle transmission fluid too.

You keep mentioning the stealers. Are you still using them for servicing? If so, time to find a good garage (Toyota Independent or another).