Transmission=weird. help

[Niko97RS]

ok ive had this car 3 years. tranny shifts fine. not the problem

the problem is thats its an A4...correct? that means i have 4 gears.

that means that when i come to a stop. at MOST my car should shift 3 times.
sounds great right?

well if i come to a stop and feather the pedal watch the tach intensely....once i hit aobut 45-50 mph....my car has SHIFTED 4 times. ill start in 1(ovb) it will shift at 15, 25, 35 and then 50 mph....for an A4 with 342, when im going 50mph im doing like 1400-1500rpms. does this mean i have 5 gears or am i going insane. someone please tell me.


ps ive done this "test" with a bunch of friends whove all seen my car shift 4 times and can verify that

[TheWizardofOz]

Re: Transmission=weird. help

I think the 4th "shift" you are seeing may be the torque converter locking up, so you may see a slight change on the tach like it was shifting, but it's not.

Mike

[Niko97RS]

Re: Transmission=weird. help

why would the TC lock up...?

[vr4gasm]

Re: Transmission=weird. help

make a video

[TheWizardofOz]

Re: Transmission=weird. help

The converter locks up to improve gas mileage at higher speeds. Due to the way a torque converter works, if it were not to lock, it would only be able to transfer 90 some percent of the power it gets to output. When it locks up, 100 percent is transfered. I think this is because it uses a fluid coupling, so even when it reaches it's stall RPM it can still move slightly slower than the input. Someone feel free to correct all this if it's wrong, or clarify anything I've said, but this is what I remember from the howstufworks article on torque converters. It helps understand them alot, I would reccomend reading it yourself.

Mike

[Niko97RS]

Re: Transmission=weird. help

hmmm a video sounds good.

[Meatyshells]

Re: Transmission=weird. help

why dont you do a full throttle test?
if i remember...
1st goes to 50mph
2nd 80
3rd will take you all the way to your speed limiter so when you hit about 90ish let off and you should feel it shift into 4th and stay there
or take your overdrive off do exsactly what you did before and then when you get to 50mph turn overdrive back on

[chevy the kid]

Re: Transmission=weird. help

Mine in cool drive shift around 2200rpm.
80 mph for the second??? it's very fast for the second

What's the difference between overdrive and drive. Does it's more power in drive?

[silvachris1]

Re: Transmission=weird. help

ok ive had this car 3 years. tranny shifts fine. not the problem

the problem is thats its an A4...correct? that means i have 4 gears.

that means that when i come to a stop. at MOST my car should shift 3 times.
sounds great right?

well if i come to a stop and feather the pedal watch the tach intensely....once i hit aobut 45-50 mph....my car has SHIFTED 4 times. ill start in 1(ovb) it will shift at 15, 25, 35 and then 50 mph....for an A4 with 342, when im going 50mph im doing like 1400-1500rpms. does this mean i have 5 gears or am i going insane. someone please tell me.


ps ive done this "test" with a bunch of friends whove all seen my car shift 4 times and can verify that

It's the torque convertor locking in. You should see a drop of around 200 RPM or so when it locks in.

The converter locks up to improve gas mileage at higher speeds. Due to the way a torque converter works, if it were not to lock, it would only be able to transfer 90 some percent of the power it gets to output. When it locks up, 100 percent is transfered. I think this is because it uses a fluid coupling, so even when it reaches it's stall RPM it can still move slightly slower than the input.

Mike

That's pretty much dead on. It acts like a gear reduction when it's locked in. Torque convertors are actually alot simplier than most people think. Inside the TC, there's a disc with directional vanes on it, it's turned by the motor. Directly opposite of that disc is another with opposing vanes. The fluid in the TC gets pushed away by the first disc. When the fluid hits the second disc, the opposing vanes catch that moving fluid and spin it. Think of having 2 fans facing each other. Turn one on and it will spin the other. Anyways, what you're feeling is just TC lockup.

Mine in cool drive shift around 2200rpm.
80 mph for the second??? it's very fast for the second

What's the difference between overdrive and drive. Does it's more power in drive?

80 does sound a bit high for 2nd, I'm thinkin it's like 76 at most. Anyways, the difference between drive and overdrive is the gear ratio in the transmission. 3rd gear, or drive (in our 4L60E at least) is 1 to 1. Overdrive (4th gear) is like 0.76 to 1. With these ratios you'll feel more power in 3rd than you will in 4th, just the same as you will in 2nd vs 3rd, and 1st vs 2nd. It's called mechanical advantage or torque multiplication. The power is still the same, but the force is being changed by the gear ratios in the transmission, and then again in the differential.

[chevy the kid]

Re: Transmission=weird. help

I've tried to drive on street on drive and it seems the car better shift than overdrive.

[pintobean11]

Re: Transmission=weird. help

I've tried to drive on street on drive and it seems the car better shift than overdrive.

I found it weird when I bought my car that you can shift directly into OD then D is below that. I know this is an old thread and I'm with chevy the kid that my car seems to shift better.

Does everyone drive around in OD or D?

[Rangersltw]

Re: Transmission=weird. help

I believe if you are in D you are not going to shift higher than 3rd gear. When you are in OD you will shift into 4th gear, speed permitting.

[inheritthefire]

Re: Transmission=weird. help

For what it's worth, my a4 w/3.42's shifts at ~40mph into 2nd, ~75mph into 3rd, and ~115mph into 4th at WOT.

[ssms5411]

Re: Transmission=weird. help

It might be just down shifting and shifting again, I know mine with 3.73's WOT run will shift out of 1st at 35, then 2nd 70, and 3rd 122 and 4th 150 around there. Like Meaty said do a WOT run on a open road, I like to go about 10-15 miles first to check it for cops or pot holes etc. Then just keep your foot all the way down and don't let up so it doesn't downshift.

[auto666]

Re: Transmission=weird. help

I think the 4th "shift" you are seeing may be the torque converter locking up, so you may see a slight change on the tach like it was shifting, but it's not.

Mike

dead nutz