Destroyed trans in 8 months?....warning graphic details involving tranny...

[lswing]

Well, the saga continues this week. Had the wiring looked at last week, drove about a 100 miles and no trans temp sensor warning has shown back up. Took the beast out for a spin today. Opened WOT in third gear tip and "bam" into 4th at about 3,500-4,000 RPM's, arggghhhh.....

All other driving is fine it seems, and did a run in Sport at WOT, but starting in first gear, and no slip noticed. With the shift points much higher I don't think the trans gets the same torque load that causes the slip when in 3rd and Tip.

I can only assume that either clutches are worn, or not enough pressure is being applied, and max torque in 3rd causes the clutches to slip and shift to 4th, I assume...trans fluid is full/new and temp is just fine, 55C today.

Newly rebuilt trans went in the car in January, 4,500 miles, probably 100-150 shifts at WOT bounced off of redline. Seems to me others have had much more luck. I also know my car runs damn strong as everything is buttoned up well, so torque numbers of 550+ out of the engine is putting a hurt on the trans.

Well, I'll keep checking for codes. I also de-tuned after today's run by maybe 10/15 hp/tq, so that should help keep it together. It actually wasn't slipping last month before I added the extra power, just enough to push it over the edge.

Hopefully there's some other explanation for the trans not holding third gear, but more doubt each time it doesn't. To be continued.....

[MaxRS6]

Oh man- that doesn't not sound good. Why don't you send it to transmission shop for them to sort it out?

[Bigglezworth]

Talk to the rebuilder. Would think that with that low of mileage and run time that it would qualify as warranty.

[905084]

Only when hot? Fluid type?

[lswing]

Only when hot? Fluid type?

As mentioned, was basically cool, 49c trans fluid temp on today's slip, 50 degree air temp, basically cold. Trans shouldn't slip due to fluid temp until 95c or more...

Thanks for the input fellas, yep, thinking this is grim. Even if we pull it and I have it rebuilt again, bummer is the $2,500 or so for labor to pull and replace. I do have an EGT going though, ughh....

Ran stock fluid the first 4 months, then Amsoil the next 4, now back on stock...

The fact it drives fine most of the time, maybe I could drag it on for another year or so, but bummer to not be able to open it up 100%.

[lswing]

Max and Bigglez, yep I could send it back at some point, as mentioned it's the pull and put back that costs as much or more is my main concern. I can pay for it, but the down time and $ are not really pleasant as you can imagine...

[lswing]

Maybe I'll have a trans shop in town take a look, I know a good one, this is still an auto trans after all...

[4everRS]

Tozo rebuild right? What does he say about it?

Sounds like you really don't have a choice as far as another rebuild......

[905084]

Well....as much as people hate it, what I did bought me an extra 3000 miles.....

[lswing]

Tozo rebuild right? What does he say about it?

Sounds like you really don't have a choice as far as another rebuild......

He said the clutch pack, even upgraded, can't handle the power, and he offered to rebuild it again. He said if you run a tuned car, and press it, you will eat the trans...this trans in it's first car before being crammed into the rs6 was meant for 300 HP...

All's I can figure is I put the hammer on this car more than others that have had it last longer.

I worry I'm going down the line of the user mmaturo, many of you know him, three trans in 3-5 years. Maybe I'm just asking too much from it...

IF i do another rebuild might keep the next one lower power and get a car with a trans that can actually handle 5-600hp...

[DHall1]

Turn down the wick just a bit. .02c

It could last another year in this state.

Find another trans core and send it out for a stout rebuild. Keep in on the shelf for the rainy day.

Edit: I just looked at your response. Get that second trans and have Tozo go thru it. He once told me that he could modify the valve body for increased line pressure output but you would feel it on the upand down shifts. I bet he would give you a break on the second trans as your building the backup for the first one with early failure. .03c

[905084]

Another option....my builder found this pipe cracked....can't remember what clutch packs it controls, but 3 out of 4 of the trans I own had this pipe cracked, which will dump clutch pressure.....certainly worth trying...I repaired mine with the end of a solder flux brush.

[lswing]

Turn down the wick just a bit. .02c

It could last another year in this state.

Find another trans core and send it out for a stout rebuild. Keep in on the shelf for the rainy day.

Agreed, already turned her down a touch...might drop timing even more just to play safe.

This was a stout rebuild, unless something went amiss...

Truth is, I wouldn't know something was wrong unless for trying some big runs in 3rd gear tip, all well otherwise, for now...thanks DH!

[lswing]

Another option....my builder found this pipe cracked....can't remember what clutch packs it controls, but 3 out of 4 of the trans I own had this pipe cracked, which will dump clutch pressure.....certainly worth trying...I repaired mine with the end of a solder flux brush.

Interesting, the boys in Europe on 246.com have talked about an ATF pipe cracking and causing issues. Thanks!

I have a very competent mechanic in town, but the details of this trans are not easy to figure out.

I would put some money on lack of pressure, it's either that or worn out clutch plates, but fluid was clean two months ago when this first started. Location of pipe please?

Since you're a pilot and part time rs6 mechanic you can fly up here right? I'll put you up for a few days while you work on the trans

[lswing]

Turn down the wick just a bit. .02c

It could last another year in this state.

Find another trans core and send it out for a stout rebuild. Keep in on the shelf for the rainy day.

Edit: I just looked at your response. Get that second trans and have Tozo go thru it. He once told me that he could modify the valve body for increased line pressure output but you would feel it on the upand down shifts. I bet he would give you a break on the second trans as your building the backup for the first one with early failure. .03c

Spoken with Tozo over the last few months, and he seems surprised it went/issues so early, and offered to fix it. From what I know trans has every upgrade possible to handle increased power...more clutches in each pack, increased VB pressure, updated springs/pins. He's a good guy to talk to, so I figure we'll catch up in the next few weeks and keep looking for a solution. Thanks!

[mmaturo]

He said the clutch pack, even upgraded, can't handle the power, and he offered to rebuild it again. He said if you run a tuned car, and press it, you will eat the trans...this trans in it's first car before being crammed into the rs6 was meant for 300 HP...

All's I can figure is I put the hammer on this car more than others that have had it last longer.

I worry I'm going down the line of the user mmaturo, many of you know him, three trans in 3-5 years. Maybe I'm just asking too much from it...

IF i do another rebuild might keep the next one lower power and get a car with a trans that can actually handle 5-600hp...

Lol...I picked the right night to be bored and poke around on this forum and your statement at the top couldn't be more true. But yes actually 4 transmission if you count the original one in the car, 5 torque converters over 60K miles (from when the first one went at 27K miles on the car) and 5 years...pretty good abuse on 3 of the 4 (stop light runs and some track days_...all on a stock strong motor (395hp and torque at the wheels on the dyno). And last tranny was going when I traded it in...with zero abuse and few miles on it (a rebuilt unit off the boat from ZF under my last possible warranty claim). Keep on rebuilding them.

My only real comment is thank goodness Audi has strengthened the transmission technology since. The RS cars are less of an experiment these days. Zero issues on my S5 after the RS6 with Stasis tune; now RS5 that I have driven way harder than the RS6 even (14 track days around the country over 1 year and 17K miles); and my R8 that sees some hard driving. I'm looking forward to the RS7 I have on order with all the power and beast feel with way more reliability.

[mik15]

lswing - maybe is time to let it go and get that AMG you were looking for , honestly this constant fear of something breaking had me in the end and decided to sell it, it is a perfect car for someone that will use it as fast cruiser, but when you start asking for more from the C5 RS6 is when you realize that it isn't up to the task on a long run. The later RS and S models are way much better, the RS6 C5 seems to be a project they did with whatever they could find in their backyard at that moment, i don't think it was a very well thought plan, apart from the DRC systems which was anyway a total failure, everything else was taken from a regular A6 and "strengthened" a bit without doing some endurance tests, just my 0.2C....

[DHall1]

I dont think we have to worry about lswing jumping ship.

Easy to say this is a backyard project. But really this is cutting edge design for what was on the road 10 years ago. Have you driven any other A6 of the era? S6, Allroad?

RS6 is on another planet. Hell, I thought I could drive the S6 Avant until such time I could convert it to RS specs but I could not stand to drive that car. I thought it would feel like the RS but it was a far cry. sold it

My 10yr old #1 is rock solid to this day. As reliable as any Lexus but faster than almost every car on the road.
My 10yr old #3 is rock solid to this day with only 1 transmission replacement and has never let me down.

We are at the mercy of what ZF designed at the time. This engine is detuned and if we turn up the wick it will wear parts. So what. I will take the RS6 and turn up the wick just to the point of safe for that ol ZF.

As for endurance tests. Someone better talk to ol Mad Max. 180k and counting and he still tracks the beast to its limits.

lswing - maybe is time to let it go and get that AMG you were looking for , honestly this constant fear of something breaking had me in the end and decided to sell it, it is a perfect car for someone that will use it as fast cruiser, but when you start asking for more from the C5 RS6 is when you realize that it isn't up to the task on a long run. The later RS and S models are way much better, the RS6 C5 seems to be a project they did with whatever they could find in their backyard at that moment, i don't think it was a very well thought plan, apart from the DRC systems which was anyway a total failure, everything else was taken from a regular A6 and "strengthened" a bit without doing some endurance tests, just my 0.2C....