Hi, After multiple fluid changes (yes, I used Volvo fluid) and updating the servo cover with no 'cure' to increasing hard shifting I've decided to install a used AW55 tranny(with warranty) in my 2007 S40T5. I've got 2 questions:

Is there any ECU or similar programming that has to be done to accept the new transmission?
Is there a good guide or write up anywhere detailing the steps to replacing the transmission?

Thanks

 

Have you tried an "adaptation"? You will need to do that to the replacement transmission. Actually you "do" it to the TCM. The TCM has adapted to the wear in your current transmission and has tried to make the shifts smooth. So the "new" transmission may shift just like the old trans, unless you do the adaptation process. Happened to my shop when we replaced a very bad trans - the new trans did not slip anymore and shifted like the old trans, but not after adaptation.

Adaptation is where VIDA puts the TCM in that mode and the car is driven in a specific fashion to have the TCM learn the best way to shift for each gear. Takes about an hour of driving to complete.

You might also consider a valve body replacement - much easier than trans replacement (and maybe more likely to fix your complaints, especially since you are getting a USED trans of unknown quality) google volvo slam shifts for many good and bad stories.

 

Keep the same TCM and applied the adaptation

 

Did you try replacing the shift solenoids? If the tranny is shifting hard, it's usually the solenoids or similar "control issue" rather than a fatal flaw requiring a new tranny.

 

I didn't think about replacing the shift solenoids. Good suggestion. I'll look into it.

 

It's really not a difficult job (I did a youtube video on the process), and it doesn't cost much. Before I swapped a tranny, I'd roll the dice. Do the adaptation and fluid counter reset, too, of course.

 

Great advice! I replaced the three big solenoids(SLT, SLU and SLS) and the transmission is shifting like brand new! No more slips, clunks, hard shift, etc. And the CEL cleared up also. No big issues with the installation. The top torx bolts on the pan were a little difficult but using a 1/4" drive with a variety of extensions worked. Also a powered ratchet really speeds things up. Next up is a new exhaust manifold gasket!

 

Glad to hear that worked out. A lot (!) of people end up replacing perfectly good transmissions because of bad / dirty solenoids (or even just worn-out fluids). On the up side, I've bought really great cars for chump change because they had transmission problems that I was able to fix cheap and easy (once bought a very nice V70 T5 for $1,400 because it needed the servo cover mod - $30 and 30 minutes!). ;-)

And yes, those top bolts ARE the tough ones (which is why I kind of obsessed about them making the video). Hardly a show-stopper, but if you take them out last, it's just adding to the difficulty.