A6 4.2 tranny problems

**AudiSport12** · 09-03-2008 10:58 PM

x-posted on AW

The car is a 2000 4.2 w/ 103k miles.

Randomly now for the past while when I drive the car cold, the first shift clunks HARD followed by the gear selections on the display screen lighting up in all red. To make it shift correctly after that, I have to turn the car off to reboot it. Then it works fine.

Today it happened twice back to back in the middle of campus with all sorts of traffic behind me. After I turned the car off, then on twice, I got a CEL. I had Autozone scan the codes and it brought up:

P0730
Definition:
Gear incorrect ratio

Explination:
Open or short circuit condition

Probable causes:
1. poor electrical connection
2. low transmission fluid level
3. failed transmission solenoid

Another weird thing that I'm concered about is when taking off from a stop and steadily driving slow in 2nd gear, when a LITTLE bit of throttle is given, it jumps down to 1st then back up to 2nd pretty quickly. Also when driving on the highway cruising around 55-60mph, if I punch the throttle, it tries to search for a gear and will sometimes slam into 2nd when not needed and then kick back up to 3rd.

Now I know these cars are known for having tranny problems, But I am not sure if this is something that can be dealt with before anything gets worse.

We already had to replace the tranny on my moms '98 A8 4.2Q (was under warranty thank god) and I'm not wanting to do that with this car either (not under warranty).

Sorry for the long post.
Any idears?

**speedydragon** · 09-04-2008 12:08 AM

have you had your transmission fluid flushed lately? I had to replace my Tip tranny outta warranty due to Audi's "lifetime" tranny oil gunking up in my tranny. It got all hard and what not then ruined my reverse. Prior to my tranny replacement, I flushed the tranny a few times to get all the old gumk out and fill it up with fresh liquids, it worked good for a while. Or maybe somethign is wrong with your TCU.

**RAUDIS6** · 09-04-2008 12:22 AM

What does a tranny flush run on average at an "Indy" shop?

**projectdarka4** · 09-04-2008 08:19 AM

110

**Limen** · 09-04-2008 10:13 AM

I know its not what you want to hear, but I had to have mine replaced around 98K miles.

Same things were happening to mine.

**speedydragon** · 09-05-2008 07:46 PM

Costed me $250 because I told my mechanic to flush it three times with new fluids each time. One bottle (not sure how much) of that fluid was either $20 or $40, I forgot.

**samaj** · 12-20-2013 02:49 AM

I have a 2000 S6 with 103,800/- KM (64,499 Miles) The Tranny was rebuilt completely by the previous owner.
Is the Auto tranny on an C5 A6 4.2 & the C5 S6 4.2 same?

The car jerks sometimes in forward gear. Sometime at slow speed & sometimes when I floor it.`
My normal drive to office is 15 minutes. So maybe the car needs warming up for it to shift smooth?

Is there a LED light on the dash which comes on when the Tranny Fluid is low?
How often do you have to replace it?

**AudiSport12** · 12-20-2013 05:45 AM

Can't remember if they are the same or not. I sold the car shortly after this post in '08 with a completely non-functional transmission. New owner did a 6spd swap in it.

**Scotty@Advanced** · 12-20-2013 05:53 AM

Originally Posted by samaj

I have a 2000 S6 with 103,800/- KM (64,499 Miles) The Tranny was rebuilt completely by the previous owner.
Is the Auto tranny on an C5 A6 4.2 & the C5 S6 4.2 same?

It's the same trans family, 5HP24 but the gear ratios are different, so they are not interchangeable.

**samaj** · 12-20-2013 07:52 AM

Thanks but are they prone to the same common tranny problem?

**rollerton** · 12-20-2013 08:56 AM

Originally Posted by samaj

Thanks but are they prone to the same common tranny problem?

Yep. Like Scotty said, basically same trans, just different ratios so they all have the same issues.

**Scotty@Advanced** · 12-20-2013 09:52 AM

Originally Posted by rollerton

Yep. Like Scotty said, basically same trans, just different ratios so they all have the same issues.

If people would service their transmissions the ZF gearboxes will last a very long time. The 2 failures not related to service are the torque converter seal and the input drum splitting. Both were design flaws, the seal was remedied from the factory around the 2002-2003 model year.

**samaj** · 12-20-2013 11:30 AM

My transmission on my 2000 Auto avant has been rebuilt completely (as claimed by the previous owner) with only the housing left original. What could cause the ocassional jerks in forward gear change? Need to let the car warm up properly. Reverse is fine.

When the transmission oil level is low. Does a light flash on the dash?