Did I damage my Automatic gearbox by cruising in 3rd Gear?
Discussion
Hi all,
I bought a 2001 Automatic 1.3L Yaris the other week. Since its an automatic (traditional) it has this button on the gear stick called Over Drive (O/D) and I believe while driving the car home on the motorway I had the over drive function off which meant the car was doing the 60 miles motorway journey on the 3rd gear the whole time with the speed averaging around 65mph. The day after, my temperature light came on so I filled it up with coolant and have been driving around and the level hasnt dropped since. So I am pretty sure it dropped in the first place because my engine got hot from driving high speed with over drive mechanism off.
So from this my question is how serious was this? Could it have damaged my gearbox and or will it increase the potentials of gearbox failing in the future? I ask all these because I am scared of the gearbox failing on me especially since its an AUTOMATIC. (I once bought a semi auto which died on me after two weeks of driving)
For those unaware of Over Drive, its the operation of cruising at sustained speed with reduced engine revolutions per minute (RPM). Its generally agreed that its good to have it off for city drive where you wouldnt want to shift beyond 3rd gear. OverDrive is ideal for highway journey as it will unlock the higher gears for smooth drive
Thank You
I bought a 2001 Automatic 1.3L Yaris the other week. Since its an automatic (traditional) it has this button on the gear stick called Over Drive (O/D) and I believe while driving the car home on the motorway I had the over drive function off which meant the car was doing the 60 miles motorway journey on the 3rd gear the whole time with the speed averaging around 65mph. The day after, my temperature light came on so I filled it up with coolant and have been driving around and the level hasnt dropped since. So I am pretty sure it dropped in the first place because my engine got hot from driving high speed with over drive mechanism off.
So from this my question is how serious was this? Could it have damaged my gearbox and or will it increase the potentials of gearbox failing in the future? I ask all these because I am scared of the gearbox failing on me especially since its an AUTOMATIC. (I once bought a semi auto which died on me after two weeks of driving)
For those unaware of Over Drive, its the operation of cruising at sustained speed with reduced engine revolutions per minute (RPM). Its generally agreed that its good to have it off for city drive where you wouldnt want to shift beyond 3rd gear. OverDrive is ideal for highway journey as it will unlock the higher gears for smooth drive
Thank You
jerrin91 said:
Hi all,
Its generally agreed that its good to have it off for city drive where you wouldnt want to shift beyond 3rd gear. OverDrive is ideal for highway journey as it will unlock the higher gears for smooth drive
Where and how have you determined that there is general agreement etc?Its generally agreed that its good to have it off for city drive where you wouldnt want to shift beyond 3rd gear. OverDrive is ideal for highway journey as it will unlock the higher gears for smooth drive
Because I don't agree.
The Mad Monk said:
Where and how have you determined that there is general agreement etc?
Because I don't agree.
i got that piece of information from the internet. At least thats what i made of the information i found? Please correct me if I am wrong though Because I don't agree.
Because I never driven proper full automatic before I didnt know what it was when i bought the car. so i chose to leave it off when driving the car home. Big mistake thoughNo 65 mph on third gear (if it was that) will not have knackered your engine, gearbox or cooling system.
Just as driving at 75 mph in 4th or O/D would not do that either, neither would driving at 85 in O/D. If the car can go that quick.
Is there a rev counter and temperature gauge?
If so what revs was the engine doing at 65 mph?
Did the temperature gauge go into the red?
Just as driving at 75 mph in 4th or O/D would not do that either, neither would driving at 85 in O/D. If the car can go that quick.
Is there a rev counter and temperature gauge?
If so what revs was the engine doing at 65 mph?
Did the temperature gauge go into the red?
JM said:
No 65 mph on third gear (if it was that) will not have knackered your engine, gearbox or cooling system.
Just as driving at 75 mph in 4th or O/D would not do that either, neither would driving at 85 in O/D. If the car can go that quick.
Is there a rev counter and temperature gauge?
If so what revs was the engine doing at 65 mph?
Did the temperature gauge go into the red?
i wasnt checking to be honest at the time. its all good now though as the car doesnt show any signs of stress it was put through. however my question is if i did any damage thats not visible now but can start to show in the future. suppose i say i was pushing the car beyond the redline for too long. what are consequences of it on the gearbox?Just as driving at 75 mph in 4th or O/D would not do that either, neither would driving at 85 in O/D. If the car can go that quick.
Is there a rev counter and temperature gauge?
If so what revs was the engine doing at 65 mph?
Did the temperature gauge go into the red?
Pericoloso said:
Why would you do that ?
Car isn't going to last long by constant thrashing.
hi pericoloso, i think you misinterpreted me. i would never do that, not even once. i was saying holding it in the redline at the time was what may have caused the car to overheat.. so will it have any consequences from that one particular instance of mishandling? Car isn't going to last long by constant thrashing.
jerrin91 said:
i wasnt checking to be honest at the time. its all good now though as the car doesnt show any signs of stress it was put through. however my question is if i did any damage thats not visible now but can start to show in the future. suppose i say i was pushing the car beyond the redline for too long. what are consequences of it on the gearbox?
Not a lot, but the engine would explode.You didn't redline the engine in any case. Based on information online the final drive in direct top gear on your car should be 4.28:1, and assuming it's on 175/65/R14 tyres you would have been running the engine at around 4,100rpm. A bit high, but not car breaking.
Speed is generally not what kills gearboxes, it's acceleration.
Unlikely to cause any damage. Automatic (not automated manual) gearboxes, especially Toyota, are very tough. I had a colleague who had a Corolla some years ago. He didn't know about the O/D switch for several years and travelled the motorway at 110 km/h daily. The car lasted 20 years (as most Corollas in Australia do!) with no transmission problems.
More important is transmission fluid - change when suggested and make sure mechanic checks level.
More important is transmission fluid - change when suggested and make sure mechanic checks level.
Think about it logically:- It's not dissimilar to using gears 1-3 on a manual gearbox, as you've said yourself. It's similar to holding it at max speed on redline for a while..
All you've done is run it at high RPM (65 in 3rd in a 1.3 Yaris is going to be up there I'd imagine) for an extended period of time; meaning the engine would get hot and possibly work through some oil, as well as plenty of fuel.
Have a check on the general fluid levels, any leaks in coolant? water pump working? etc.
With regard to switching off O/D In town, I wouldn't bother - If you're going to let the car pick the gear, let it pick the gear - If you need to drop down, It'll kick down for you.
All you've done is run it at high RPM (65 in 3rd in a 1.3 Yaris is going to be up there I'd imagine) for an extended period of time; meaning the engine would get hot and possibly work through some oil, as well as plenty of fuel.
Have a check on the general fluid levels, any leaks in coolant? water pump working? etc.
With regard to switching off O/D In town, I wouldn't bother - If you're going to let the car pick the gear, let it pick the gear - If you need to drop down, It'll kick down for you.
I may have misunderstood and so be about too make a tit of myself, but is the feature you think you've got really an 'overdrive' function? It sounds very much to me like the 'D3' thing I had on an old Accord, which meant it wouldn't go above third gear and the purpose of which was to ensure you always had some engine breaking on long descents if you needed it. To have to turn a proper overdrive function on in order to be able to shift above third (which you'd probably do at about 25mph in a Yaris) seems mental tbh.
have you read the user manual for your car?
overdrive ON means you stay in 3rd gear it acts like a kick down function and can be used for overtaking.
Overdrive OFF means the car will select 4th gear when it is suitable.
Still, you being in 3rd gear on a motorway does not explain at all how you lost coolant and i suspect the coolant was low.... id be more concerned about driving around with no coolant in any gear that worrying an autobox/engine will explode because its done 4000rpm
overdrive ON means you stay in 3rd gear it acts like a kick down function and can be used for overtaking.
Overdrive OFF means the car will select 4th gear when it is suitable.
Still, you being in 3rd gear on a motorway does not explain at all how you lost coolant and i suspect the coolant was low.... id be more concerned about driving around with no coolant in any gear that worrying an autobox/engine will explode because its done 4000rpm
I've always assumed that Toyota used "overdrive" for 4th gear in an automatic in order to make it familiar to drivers in the USA.
Many (most?) American automatic gearboxes were 3-speed, or even 2, and when the interstates were built, leading to higher cruising speeds, it became common practice to add an aftermarket or factory-fitted 4th, overdrive (i.e. higher than 1:1), gear to the 3-speed. This was a separate unit, bolted between the gearbox and a shorter propshaft.
I guess that American drivers were used to a separate control for overdrive, so this arrangement continued, even when the car was fitted with a true 4-speed 'box. The Japanese manufacturers just fell in line with the American car companies.
You can still buy an overdrive auxiliary gearbox in the US.
This is a Gear Vendors o/d unit:
EDIT:
The true meanng of "overdrive" in relation to gear ratios is "higher than 1:1". The highest gear in any gearbox was invariably 1:1, because the direct drive was most efficient. When auxiliary gearboxes were developed to reduce RPM at cruising speeds, like the Laycock de Normanville unit on your Grandad's MGB, they were colloquially known as overdrives. Many 5- or 6-speed manuals still have overdrives. An extreme example is the Corvette, which has a double-overdrive transmision - 4th gear is 1:1, while the overdrive 5th and 6th gears can be as high as 0.71:1 and 0.50:1 respectively.
Many (most?) American automatic gearboxes were 3-speed, or even 2, and when the interstates were built, leading to higher cruising speeds, it became common practice to add an aftermarket or factory-fitted 4th, overdrive (i.e. higher than 1:1), gear to the 3-speed. This was a separate unit, bolted between the gearbox and a shorter propshaft.
I guess that American drivers were used to a separate control for overdrive, so this arrangement continued, even when the car was fitted with a true 4-speed 'box. The Japanese manufacturers just fell in line with the American car companies.
You can still buy an overdrive auxiliary gearbox in the US.
This is a Gear Vendors o/d unit:
EDIT:
The true meanng of "overdrive" in relation to gear ratios is "higher than 1:1". The highest gear in any gearbox was invariably 1:1, because the direct drive was most efficient. When auxiliary gearboxes were developed to reduce RPM at cruising speeds, like the Laycock de Normanville unit on your Grandad's MGB, they were colloquially known as overdrives. Many 5- or 6-speed manuals still have overdrives. An extreme example is the Corvette, which has a double-overdrive transmision - 4th gear is 1:1, while the overdrive 5th and 6th gears can be as high as 0.71:1 and 0.50:1 respectively.
Edited by gareth_r on Wednesday 18th July 23:42
Gassing Station | Advanced Driving | Top of Page | What's New | My Stuff