Questions regarding A/T- D, 2, L?

**oj88** · February 19th, 2009 12:21 AM

I find it weird that Toyota would put L and 2 and advice drivers not to use them. Why will the A/T overheat? Don't they have a lock-up clutch?

**woohoo** · February 19th, 2009 08:00 AM

Originally Posted by oj88

I find it weird that Toyota would put L and 2 and advice drivers not to use them. Why will the A/T overheat? Don't they have a lock-up clutch?

Sorry, I forgot the important part: FOR EXTENDED PERIODS ("for a long time" in the manual). My bad.

Here's the mentioned page, by the way:

**oj88** · February 19th, 2009 08:21 AM

^ Thanks for that. Still is weird that their A/T can't cope with that. Should I assume that they really don't employ a lock-up clutch? To the uninitiated, the lock-up clutch holds the two sides of the torque converter together under specific conditions. This is so that there's no torque loss due to fluid coupling and generally little to no heat is generated.

I would love to see the specs on the Avanza tranny.

**woohoo** · February 19th, 2009 09:50 AM

Originally Posted by oj88

^ Thanks for that. Still is weird that their A/T can't cope with that. Should I assume that they really don't employ a lock-up clutch? To the uninitiated, the lock-up clutch holds the two sides of the torque converter together under specific conditions. This is so that there's no torque loss due to fluid coupling and generally little to no heat is generated.

I would love to see the specs on the Avanza tranny.

I think it would have been better if they specified how long is "too long."

Is this what you're looking for?

**_Qwerty_** · February 19th, 2009 10:05 AM

dont forget to turn OD off when using L or 2.

**oj88** · February 19th, 2009 10:56 AM

Originally Posted by woohoo

I think it would have been better if they specified how long is "too long."

Is this what you're looking for?

Thanks but not really what I'm looking for. It's more of a parts list than a document about its description and operation.

Originally Posted by _Qwerty_

dont forget to turn OD off when using L or 2.

No need. As per the manual attached by woohoo, selecting "L" will put you in 1st gear with no possibility of shifting up. "2" will allow the tranny to use either 1st or 2nd gear. "OD" is only applicable in "D" (1st - 4th gear). Having the O/D turned OFF will only allow you 1st - 3rd gear in "D".

The last gear is usually the O/D.

**Yoda** · February 19th, 2009 11:22 AM

I see a lot of advice on these A/T threads about using L or 2 when climbing para daw mas malakas ang hatak, etc.

Uhm, no.

The reason why it's called an automatic is because the system will select the correct gear depending on the current conditions. From a standstill, selecting D or L will have absolutely no difference. Either selection will make the car roll forward in first gear. As you gain speed, dyan na magkakatalo. D will shift up to 2nd, 3rd, etc once the conditions are right. L will stay in first gear no matter how hard you press on the gas and how fast you're going.

So para hindi sumakit ulo nyo, put the sucker in D, set O/D to on and drive away.

You'll live through a majority of driving conditions that way. Very, very rarely will you need 2 or L.

**oj88** · February 19th, 2009 02:36 PM

Originally Posted by Yoda

I see a lot of advice on these A/T threads about using L or 2 when climbing para daw mas malakas ang hatak, etc.

Uhm, no.

The reason why it's called an automatic is because the system will select the correct gear depending on the current conditions. From a standstill, selecting D or L will have absolutely no difference. Either selection will make the car roll forward in first gear. As you gain speed, dyan na magkakatalo. D will shift up to 2nd, 3rd, etc once the conditions are right. L will stay in first gear no matter how hard you press on the gas and how fast you're going.

So para hindi sumakit ulo nyo, put the sucker in D, set O/D to on and drive away.

You'll live through a majority of driving conditions that way. Very, very rarely will you need 2 or L.

There are situations that the A/T logic can be confused, especially on a long uphill climb. The end effect could be that your A/T would continuously cycle between gears as it hunts for the best torque suitable for that climb. The L and 2 settings are a way to prevent this as you pretty much have full control of your speed of accent and RPM. You can then shift to D as road conditions improve.

If your A/T has grade logic or similar fuzzy logic intelligence, it may retard the up-shift but they're still subject to certain programming limitations.

**woohoo** · February 19th, 2009 03:34 PM

Originally Posted by _Qwerty_

dont forget to turn OD off when using L or 2.

No need to turn O/D Off, walang epekto sa L or 2 iyan. Sa D lang meron epekto...

**woohoo** · February 19th, 2009 03:40 PM

Originally Posted by oj88

There are situations that the A/T logic can be confused, especially on a long uphill climb. The end effect could be that your A/T would continuously cycle between gears as it hunts for the best torque suitable for that climb. The L and 2 settings are a way to prevent this as you pretty much have full control of your speed of accent and RPM. You can then shift to D as road conditions improve.

If your A/T has grade logic or similar fuzzy logic intelligence, it may retard the up-shift but they're still subject to certain programming limitations.

I didn't experience this gear hunting issue when I went to Baguio, but I did experience this a couple of times: The speed of the jeepney in front was in a borderline zone (with respect to my ride's gear shifting), and while no gear hunting occurred, it also didn't downshift to get more power. Somehow I felt that the engine was struggling. If it was a diesel engine, I suspect it would've created a "smoke screen" behind me

. I had to downshift it to 2 manually so I could overtake the jeepney safely.

Maybe this gear hunting issue is a thing of the past (read: applicable only to old A/T's).