RS6 C5 2002 big gearbox problems

[RS6Leigh]

Hi all,

im new to the forum, but hoping somebody can shed some light on this as I'm at a loose end at the moment.

A a few weeks ago on a motorway with the box in manual mode I hit the kickdown. It changed down to 4th, but as it changed up to 5th it completely missed the gear and hit the rev limiter. As I came to a stop at the next roundabout the car then wouldn't go forward, but eventually banged hard into gear and set off again.

So i tried changing the oil and filter, but this seems to have made it worse.
It then errored up on the dash and got stuck in 3rd or 4th.

It now won't move forward or backwards without a hard Rev.

I I will be doing any repairs myself, but at this stage I'm looking for the simple fix before starting the dreaded job of taking the gearbox out.

Any my help will be massively appreciated.
Thank you, Leigh

[RS6Leigh]

1677616777

[G2]

Is it currently possible to view live data in the trans? If not would check related fuses. And the harness thru plug connector at front of trans. The plug is often contaminated with oil. Haven't seen any per se shift issues from this so far, but is precautionary. I use a special electrical connector spray and dielectric grease when servicing the trans.

Otherwise sounds like the trans had a bad day...most will default to 3rd gear. That may cause the TCC clutch to stay open (otherwise the engine would stall in 3-4 gears)

Assuming that gear changes via TIP are not possible?

What did the oil look like when drained? Debris and metal bits?

Might also check the Facebook group 'Audi RS6'; see if someone had the same issues.

Best of luck but, prepare for the worst as they say. Keep us posted.

[RS6Leigh]

Hi G2,
Thanks for the info. Yes it is possible to read the data live.
I will have a look at the wiring harness, that would be a nice fix as I am preparing for the worst.

It is not possible to change gear via tip.

When I drained the oil it came out red, and was free of metal or debris. The new oil was genuine Audi oil and was golden in colour, so I am assuming somebody has just filled it with any ATF in the past.

After I changed the oil I took the car out for a drive, and it performed normal through all of the gears for about 3 miles, and then slowly got worse. It now barely moves forward at all.

[G2]

Sure thing, hope it might help.

Knowing those points helps some: Not a good sign the TIP function is inop. Nor reading live data. Means the harness plug is probably fine. The Temp Sensor will cause hard shifting. May have spiked causing a hard shift and then broke something....

You can try following the related trouble tree diagnosis info for related codes. Worth a try.

Not a fan of OEM trans fluid for this car. I tend to see a lot of metal debris (very small flecks). Shift well, but wouldn't use it for long. Not meant for 500+lb/ft of Torque in a 415lb/ft rated trans (that's 12yrs old).

In the grand scheme it's likely time for major trans work. Hope you get a lucky "break".

[lswing]

Step 1, don't use kickdown switch.

Step 2, new trans needed it sounds. The one that completely blew on me had exact symptoms, toasted clutches. Check fluid and guess it's full of debris, or it was before someone changed it and sold you the car.

Those codes might not relate to your issue.

Update location in your info, repairs and VIN will shed more light on the issue.

[RS6Leigh]

My transmission was supposedly rebuilt not too long ago. I found the invoice earlier.
My car is tuned. It's making 560hp with 842ft/lb

[RS6Leigh]

16780So according to this it was reconditioned on the 1st of October 2012.

[lswing]

My transmission was supposedly rebuilt not too long ago. I found the invoice earlier.
My car is tuned. It's making 560hp with 842ft/lb

Dyno sheet? No. 842nm yes. 2012 is a long time ago. My second modified box slipped after 8 months, running tuned as in my sig. You've chatted up rs246.com right, not a bad group for a bunch of punters:)

[RS6Leigh]

Yes, 842nm. Sorry, it was late.
I wish it was 842ft/lb.
Ok, so I'm going to try the things you have all said here probably this afternoon, so I will be back with some answers later.

Thanks for for you me help guys, this is the first time I've had to do anything to it so it's all a big learning curve.

[DHall1]

Go see unit 20 or mrc

[RS6Leigh]

Hi guys,
move not had chance to have a proper go at this fault yet as I've been flat out with work, but I'm hoping to have a look at the electrical connector on Monday and then go from there.
I'll keep you posted.
Cheers.

[fukinavit]

Not a fan of OEM trans fluid for this car. I tend to see a lot of metal debris (very small flecks). Shift well, but wouldn't use it for long. Not meant for 500+lb/ft of Torque in a 415lb/ft rated trans (that's 12yrs old)


what magical trans fluid do you use then?

[EINHORN]

BND, I'd guess