Gear Selection On Mkiv

[Mark Sparrow]

I've recently changed my trusty MkIII LS400 for a MkIV DHP-much improved in many ways over the old model but it has an annoying habit-after slowing down on the approach to a roundabout/junction etc and then attempting to accelerate when my way is clear the gearbox seems to hesitate before selecting a gear, resulting in either an enforced slow pull away on light throttle while I sense it thinking about gear selection ,or if speed is of the essence a huge jolt in the back if I apply full throttle. Is this a trait of the five speed gearbox (my previous LS400 was no trouble in this department, or is there a problem I should be looking into? Would love to hear from anyone who has experienced the same, or has some advice on the subject-regards, Mark.

[toxo]

Do you have a service history - when was the last time the transmission fluids were changed? I had this issue with an auto supra and it turned out to be that there wasn't enough gearbox oil in the box.

[plastic orange]

Mine does it from time to time (gearbox fully serviced too), and always when you least want it. I keep mine in sport mode which seems to keep it to a minimum though.

Pete

[Mark Sparrow]

Do you have a service history - when was the last time the transmission fluids were changed? I had this issue with an auto supra and it turned out to be that there wasn't enough gearbox oil in the box.

Hi Toxo-I have the service history-and it only has 56,000 miles on the clock, but I will check the gearbox oil again-thanks for the advice and I'll let you know how it goes-regards, Mark.

[Mark Sparrow]

Mine does it from time to time (gearbox fully serviced too), and always when you least want it. I keep mine in sport mode which seems to keep it to a minimum though.

Pete

Hi Pete-I was out in it last night and selected power mode just to see if it improved-great minds obviously think alike! Unfortunately I wasn't on a long enough journey to notice much difference, but I think I may take it out for a long drive this weekend and see what happens. Thanks for the advice-regards, Mark.

[passman53]

Hi,

I seem to remember this problem being discussed 2/3 years ago. Certainly my mk4 did just the same, just a little bit of extra pressure on the pedal and it would change down to 1st and really go much faster than I wanted/expected. I did get used to it though. From memory it was not a gearbox fault but the change from a cable accelerator to electronic, which seemed to be more "delicate". I hope this makes sense as it is from memory. I don't remember sport mode made much difference except that all the changes were more responsive when you put your footdown.

Not sure but I think it was Steve Bedford who originally raised this topic.

Pete

[ManicMark]

Hello I seem to remember the mark4 gearbox has a self learning ecu & adapts to your driving style, mine didnt seem to change when I felt it should to begin with, but all is OK now. If ive adapted my throttle position to it or it has to me I will never know.

[david_hornet27]

Mine also has this problem and has for the 18 months I have owned it. It is common and I have in the past found a thread relating to it. I do not think there is a cure apart from adapting to it, I changed the transmission fluid and it made no difference... You will get used to it, but it is strange that a car that is so well engineered and perfect in almost every other way suffers from this.

[mike213735]

I have been watching this thread with interest as my '98 MKIV also does this.

I was looking to change the gearbox oil just because of this, even though the car has a full Lexus service history.

I don't think I'll bother now, I'll just get used to it as I consider it a small price to pay as, as david_hornet27 said above, the car is "perfect in almost every other way".

BTW david, I too am in Reading, keep an eye out for a Gold '98 MKIV in south Reading, that'll be me :)

Thanks

Mike

[Mark Sparrow]

Thanks to all of you for your thoughts on the subject-I suspect that I will have to get used to it (or it used to me!), but as seems to be the general consensus it's a small price to pay for a wonderful driving experience! Will keep you all posted if anything changes-Mark.

[Redsteve]

Hello Guys,

I was suffering the same problem in my MK IV too.

I have pretty much solved my problem by adjusting the throttle cable. It had about half an inch of play in it before it was doing any work. Now I have tightened it the car is so much smoother to pull away and the gears change quicker as your input on the pedal is directly linked to the engine rather than having a delay as the cable takes up the slack.

It was only a five minute job and it has transformed my car.

Hope this helps.

Steve.

[SteveLS400]

Hello Guys,

I was suffering the same problem in my MK IV too.

I have pretty much solved my problem by adjusting the throttle cable. It had about half an inch of play in it before it was doing any work. Now I have tightened it the car is so much smoother to pull away and the gears change quicker as your input on the pedal is directly linked to the engine rather than having a delay as the cable takes up the slack.

It was only a five minute job and it has transformed my car.

Hope this helps.

Steve.

Hi Steve

I think similar advice applies to earlier models; if the cable/s are not correctly adjusted symptoms include those described here and the noticeable gear changes mid range.