Interesting Transmission Activity

[subsince77]

I have been noticing something interesting in the way this AT works. Remember it's my first. I wasn't sure it was really happening until today. When I am driving up a long incline, a mile to three miles say, I have noticed that prior to an actual gear shift, there is something that happens that raises the RPMs just a little and gives just a small boost in power.

 

I thought I was imagining it at first, but today I really documented it. Several times I would be cruising uphill, still in fourth, at about 2250 rpm. As the hill steepened just a little, putting a slight bit more demand on the engine, but not quite enough to force it to shift to third, I would feel, hear, and see, the RPMs rise about 250 to 300 rpm. So it would go from say 2250 to 2600. It did this several times. Sometimes that little boost would be enough to keep it in fourth ( I think it has done it in third also). Other times, either the terrain, or I, would force the shift, and it would jump to the new gear and up something like 700 rpm or more, depending on what I did with the throttle.

 

What the heck is that? Has anyone else experienced this? I am as certain as i can be that i am not causing this with my foot. It almost feels like some kind of half step when the car is nearly ready for a shift. Spooky, or cool, depends on what it is.

[nipper]

That is the lock up torque converter unlocking.

 

BTW on hills you may be btter to not use cruise as they tend to drop down too many gears and hold it for too long then is needed. Also in a really hilly section where you notice the car hunting for a gear leave it in D3 and everyone will be happy.

[Fairtax4me]

Wut he sed. ^ 100% Normal operation. Forgetaboudit!

[subsince77]

Cool. Yeah, I never use the cruise on passes. The first time it woke me up by jumping two gears before i thought it would shift, right up to 5900 rpm to try to hold speed, I got that.

 

Much of the time on the gentler stuff, 4 & 5%, just using Sport is plenty, otherwise I drop it into 3 in manual. On Monarch pass I have used 2 on the really steep section at about 50 mph. 3 feels a little luggish. I may try to just hold 3 next time for fuel sake, but I don't think these engines are happy pulling grades below 3000.

 

They seem to love the 3500 to 4000 range on the steep stuff. I know it uses more gas, but there is more to a happy engine than fuel economy. I just try to make up for it the rest of the time.

[subsince77]

Dang it. Now I'm going to have to google locking torque converter so I know what that is. Who knew getting a newer/ different car would be so time consuming. Just interesting stuff to a die- hard MT guy.

[nipper]

Dang it. Now I'm going to have to google locking torque converter so I know what that is. Who knew getting a newer/ different car would be so time consuming. Just interesting stuff to a die- hard MT guy.

 

 

So then neweer to you is an auto from the late 1970's or newer

 

http://auto.howstuffworks.com/automatic-transmission.htm

 

http://www.edmunds.com/car-technology/automatic-transmissions-what-makes-them-work.html

 

 

Then after that in another 15 uyears we can explain (and by then we will all know) how manu-matics/multiple clutch manuals work and which tend to blow themselves up the quickest.

 

I am taking bets on that last one BTW.

[987687]

A couple things I wish from the auto... I wish the TQ would lock in 3rd, and I wish I could make it hold in 4th. Sometimes going up long hills (I live in a very hilly area), it'll downshift to 3rd. Accelerate too much, so I lift off, then it'll shift into 4nd, but a tiny more gas to maintain speed it goes to 3rd again.

Also, when I slam the gas to the floor, if I'm going over 40 it won't downshift to 2nd unless I put the shift selector into 2nd.

 

But what's happening with yours is normal..... Swapping mine to a manual to fix all these issues.

[subsince77]

So then neweer to you is an auto from the late 1970's or newer :.

 

Yes, I realized that it isn't so much that it is a newer car, but my unfamiliarity with automatics of any age. I have driven them of course, but emphatically refused to own one until now.

 

As to the issue of shifting, hunting gears, on hills, If this didn't have the sport shift and such easy access to manual gear selection, I would definitely hate it in the mountains. But as it is, it works very well.

[nipper]

A couple things I wish from the auto... I wish the TQ would lock in 3rd, and I wish I could make it hold in 4th. Sometimes going up long hills (I live in a very hilly area), it'll downshift to 3rd. Accelerate too much, so I lift off, then it'll shift into 4nd, but a tiny more gas to maintain speed it goes to 3rd again.

Also, when I slam the gas to the floor, if I'm going over 40 it won't downshift to 2nd unless I put the shift selector into 2nd.

 

But what's happening with yours is normal..... Swapping mine to a manual to fix all these issues.

 

 

1- No, as it used for pulling a load or adding breaking fdorce down hill.

2- no you will lug the engine.

 

The torque converter multiplies torque at a 2:1 ratio ( I think it is actually higher) and needs to be unlocked to multiply power for hills.

 

Keep the car in D3 for hilly areas.

 

Last one, change the tranny fluid and lest see if that goes away.