Auto Trans Experts - please chime in

[yoyoyoda]

Here is a thought, maybe get the sump gasket checked too, if its leaking fluid then that will definatley cause that symptom.

Or try magic fluids. I can vouch for Lucas products.

http://www.youtube.com/watch?v=WjNbeInU6-4

[Arragonis]

I'll get the fluid level chacked on Monday at the place that does our work vehicles, and then get underneath when the bit of weather we are having here at the moment clears - my garage is full of MGB.

[Arragonis]

ps. I missed your post. New gasket was fitted at the same time, no leaks under the car either.

Also that falcon link is similar but opposite - the guy there is saying his is worse when warm, mine is worse when cold.

I'll start the process tomorrow.

[Arragonis]

OK - Booked in for the fluid to be checked Friday together with a few other issues.

For the past few days I removed the grill block (temps getting to 105 C) and also drove Hermann like a normal auto driver - i.e. no use of N when coasting.

Guess what ? Issues more or less went.

No snatchiness even when cold, 2nd-3rd is still "pausing" but much less than before and no jerking in other gears.

I even found Hermann behaving like an excited puppy on A-roads again - the flappy paddles are responsive (there is a Clarkson annoyingly long pause of about 0.5 seconds as usual) and changes using them are smooth again.

I have tapped that the gearbox seems like the gears are being worked by someone who is drunk and wearing boxing gloves but at least the boxing gloves are gone.

I'll still get the levels checked though, amongst a few other items...

[yoyoyoda]

That's great to hear, if your temps are higher in the transmission it can cause issues like slippage.

Transmission fluid if its not in the right temperature range can cause all sorts of issues not to mention a shorter life span.

I would suggest that if you want to keep the air dam that you install an external transmission cooler and put it in front of your a/c evaporator and radiator. Just be careful and get it properly installed with the right fittings, doing a half-assed job on your expensive vehicle with an auxiliary transmission cooler could end badly. When you use clamps and ordinary rubber hose on transmission coolers they can end up popping off.

I would also recommend that you get a temperature gauge and measure temps of your transmission housing just to be sure its that, a cheap infrared no contact thermometer will work just fine and let you check temps elsewhere too.

Either that or make up an aluminium cowling which will scoop up some cool air from the airstream below your car and let it push air onto the transmission.

Depending upon your current weather situation that could have been the issue all along, the front air dam.

[War_Wagon]

I don't know about Audi's specifically, but many newer computer controlled automatics "learn" the way they get driven. If you always drive with your foot to the floor when passing people, the ECU will get in the habit of ramping up line pressure and holding your shift points longer when you are at WOT for example. It's also why weird things like a faulty mass air meter can make the transmission act up - the engine may not have a lot of load on it, but the signal the ECU is getting from the faulty meter is confusing it, so it won't apply the correct line pressure, shift points, etc for the given engine load/RPM. My genius tech friend explained it to me much better than that, but that's the "I drive a '90 Civic 5 speed" technical version of it. When he services a transmission in a vehicle that has had a hard life trying to get it to smarten up, after the fluid/filter change etc, he will disconnect the battery for a few minutes, then take the vehicle for a long test drive, taking it easy. The ECU has been reset by the battery disconnect, and for the first while of the test drive it's "learning" to shift/act normally again.

If driving your car "normally" seems to result in the transmission not acting up, it seems to me that the transmission had originally learned to operate normally, and perhaps your hypermiling techniques were confusing it? The same way a faulty sensor would cause it to act up, the ECU is looking for one set of learned parameters and is stumped with what it is actually receiving. For what it's worth, it's free to disconnect the battery, try it and then just take the car for a normal drive, see if it does anything weird. My advice is free so take it for what it's worth ha ha, good luck.

Edit: Adaptive transmissions, that's what they are called, now I remember. Here's some idea of what I was getting at http://www.thetruthaboutcars.com/200...transmissions/

[Arragonis]

Originally Posted by yoyoyoda

That's great to hear, if your temps are higher in the transmission it can cause issues like slippage...

Update today - my local specialist checked the fluid level for me (for free!) and noted it was at the right level and of good quality - at that point I said it had just been changed so that got a thumbs up.

They did a full on check of the rest of the car and noted a front suspension wear problem (which I knew about) and some software updates needed.

I've booked it back with them for the suspension and engine SW update (one of 3 needed, none are for the trans) next week. I planned to do these anyway and these guys seem quite good so a good time to do it. I have a few other issues to sort as well which they also detected without me telling them which is good - for me anyway.

I would get under the car myself but my drive is a steep slope and this is Scotland which is bloody cold. I do have to remove the rear bumper tomorrow to fit a new parking sensor though.

Originally Posted by War_Wagon

I don't know about Audi's specifically, but many newer computer controlled automatics "learn" the way they get driven... If driving your car "normally" seems to result in the transmission not acting up, it seems to me that the transmission had originally learned to operate normally, and perhaps your hypermiling techniques were confusing it?

I wondered about this too, however as part of the fluid change there is an "adaption procedure" which reprograms the box to adapt to new fluid - the garage did this twice and I've (tried do) do it myself.

Although thinking further maybe the car is adapting itself to it's first "caring owner". The DPOs (Dreaded Previous Owners - a classic MGB owners' term for normal people) seem to have accepted the idea of Audi long life service which means an oil change at 18K (if lucky) and no gearbox fluid change at all - as it is "sealed for life".

So maybe it is in a state of shock ?

[yoyoyoda]

Originally Posted by Arragonis

Update today - my local specialist checked the fluid level for me (for free!) and noted it was at the right level and of good quality - at that point I said it had just been changed so that got a thumbs up.

Good good gooD

So maybe it is in a state of shock ?

Poor thing, maybe give it some comfort by talking to it ?

Here is your problem:
Did you start the learning process when the car is on a hill? if so then that could cause some problems for the transmissions learning process..

In Subaru’s case, a Transmission Control Module sits at the heart of their four speed adaptive autobox. Sensors tell the ECU (Electronic Control Unit) when the car’s going uphill, downhill or around a corner. The black box directs gear changes according to event-specific algorithms designed to make those experiences “better.” Selecting Sport mode calls-up a different internal 'map' or program which allows higher engine speeds during acceleration, and delivers more responsive downshifts when the guy in front of you doesn’t slide over to the right.

I would suggest that you re-start the learning process and just park it on a flat surface until everything has settled down.

If its at all possible =D

[Arragonis]

Long time no update in this topic.

The box has been behaving better since redoing the adaption process but still has occasions where the changes seem quite harsh. Case in point this week during our round UK tour after 2-3 hours of cruising in 6th the changes down after that seemed very harsh for a while and then eased up. Changes up were as smooth as ever.

Been doing some reading and found this about changing fluid - I did mine at 81K. It could cause problems maybe :

The reason for this is your old fluid is thicker, and as a result helps seal all the stuff that's worn out inside the transmission. Take that thick fluid away and put in new thinner fluid, and it slips past all the areas the old fluid was sealing. Once this happens, the transmission can no longer function as it used to.

I also wonder about the torque converter clutch - I wonder if when hot after a long cruise it doesn't disengage all that well so the trans remains locked for a split second in other gears. I also wonder if this clutch remains stuck on for a short while when starting from cold.

There are no error codes, no fluid leaks anywhere so not sure what else to try.

Again ideas welcome.