Hey Everybody,
I'm having some disconcerting experiences with my 2004 Coupe's auto tranny. The car has some modifications (most significant is a magnusson supercharger) though the drivetrain from the block to the wheels is stock. I run 6-8 HPDE events each year and the trans temps consistently get above 200 on a track day. The car is equipped with a tranny cooler. No stall converter or shift kits. I had a local lube shop replace the fluid recently with Mobil1 synthetic but they didn't change the filter.

The symptoms I'm experiencing are long slow sluggish shifts from 1-2 and even worse from 2-3 (slipping?), especially under heavy acceleration. Lately, the slippage has been bad enough that the engine hits the rev limiter when shifting under hard acceleration. I did not notice any changes after changing to the synthetic fluid.

As a reference, I have a video on youtube where you can hear the 2-3 shift. Below is the link and you can hear the shifts at around 1:20 and 3:12 in the video.

http://www.youtube.com/watch?v=E3j8ZGZ9XW0

Currently, the shifts have gotten a bit worse. I'm hoping this is can be resolved with some computer tuning or a change to an appropriate fluid with filter change.

Any help troubleshooting is appreciated. Get as technical as you want, I'm all for learning a little something here.

 

You may be able to make some adjustments with a tune, however if you have a maggie, it is only time when your trans is going to blow up. I would just bite the bullet and spend the 2500-2800 on a level 5 or 6 RPM trans. Until then, take it easy on the car to avoid a tow, GL!

 

i recently have gone through the trans a4 problems. one thing that came up during the very first of this was the fact that the exhaust goes so very close to the trans that if it moves closer to the trans for some reason, and i mean like only a half inch it causes the trans fluid to bubble which has a huge impact on how the trans is operating. i am no mechanic and this may be lore at best, but it made all the sence in the world to me. good luck, i pulled mine out and ended up doing the WHOLE drivetrain!! by choice of course

 

You've been living on borrowed time - the time has come for you to give the guys at RPM transmissions a call.

 

Background : From the factory GM in order to please a variety of customers try to make the shifts "seamless " on an A4--To accomplish this they have to slip the trans clutches--This gives them more seamless soft shifting --Bad thing is that slipping clutches create heat and premature wear
Trans tuning with EFILIVEor HP can correct this and give you firm crisp shifts and almost eliminate the slipping---As your trans adds up the miles and number of WOT shifts things begin to wear out and your trans begins to skip over the shift point and hit the safety rev limiter---This is quite common---
Again you can correct this with tuning
Bad news is that it may be too late---and it may have beome eccessively worn by driving it too much with soft shifts and with your high HP--and it may just need a rebuild-
I would still seek out a tune---as you may be able to save it --and even if you need a new one--you'll need the new one tuned as well or the same thing will happen again----
PS: personally I do not like a mechanical shift kit on a computer controlled trans-- it does not make proper line pressure adjustments usually and makes full line pressure all the time---A computer tune will make it shift just as firm and crisp-- and your ECM won't be fighting the shift kit all the time--

 

that actually makes perfect sense, but the RPM trannies come with upgraded (shift kit comparable im sure) valve bodies. no real way around what you mentioned here, other than tuning it down, which seems counter intuitive?

 

you may be right :/

day 2 of an HPDE event this past weekend and the transmission refused to make the 2-3 shift.

we're exploring options now...inspect fluid/tune/and see how much longer it will last; swap it out for a built tranny; perhaps convert it to a 6-speed manual. The auto tranny simply isn't made for the track imho.

Anyone familiar with automatic to manual conversions on the C5 Coupe...something that can stand up to the hp from the maggie?

 

thanks for the background info, i find stuff like this quite helpful!

 

Call RPM ( http://rpmtransmissions.com/ ) you can get the trans and whatever conversion parts you need from them as well.

I converted from an M6 to an A4 for drag racing. If I were set on auto cross I would have definitely kept the stick.