Hey guys, so im having issues with my transmission. it all started when my diff blew and then sent an trans fault code on the dash, replaced the diff the light was still there… so i replaced both boards on the mech unit and used oem fuild and did the adaption everything worked fine took it for a drive same issue… while installing the mech unit i could not get the shift forks to slide at all they felt stuck 1 and 2 from the very top the other ones moved freely… im just lost right now as i am not sure if i should keep looking at the mech unit as the issue or do i have bad shift forks.
If the Forks themselves don’t move or move only with a lot of force then it sounds like a mechanical issue. Gears binding or a bearing going bad. No way to tell for sure without removal and dismantling it. If you can’t move them by hand, then the Solenoids will never be able to move them.
1 Like
I feared this …
I flatbedded my car to the dealer and the tech was able to come out with a Panasonic toughbook with Wifi and code it as it sat on the trailer by the back door of the service department. Took him less than 20min. Will vary by dealer but they charged my around $300+
What are your symptoms? They are not real complicated for an Automatic, Mechatronic electrics are fairly easy to replace. Some sensors require a more extensive dismantle. Clutches aren’t too bad. Mechatronic Mechanical is probably best to go with new although a few N. America big transmission places say they rebuild them and guarantee them but if you have to pull it out and swap it they aren’t going to cover the labor. Solenoids are easily replaceable on the Mechatronic unit. The transmission is basically made by a combination of Borg Warner and VAG.
2 Likes
The Speed sensors (x2) are in the gearbox section at the back of the DL501. I’ve seen on Youtube where somebody removed the gearbox section with the transmission in-place, in the car. I’ve seen a DL501 apart and the two sensors are just mounted on either end of a little stamped piece of sheet metal bracket. The book answer for them is:
Determination of the Clutch Output speed for computing clutch slip.
Determintation of Syncronization speed for shift control.
I’ve got the old DL501 out of my car that I want to tear down someday and build it up from new and/or improved parts but haven’t had the chance to do anything but remove the clutch basket. I’m currently living in Hawaii and my shop and most of my cars are living in WA state 
Not sure where you live but pulling the rear gearbox section off and installing the Speed sensors looks farily straight forward. The Drive Position sensor is right next to the Speed sensors so I would definitely replace that while I had it apart as they’ve definitely given issues to many on the forums over the years. Is yours a NSD or PXL transmission?
Hate to post it but these are the going rates from Audi. Suffix with an ‘X’ means remanufactured. I think the ‘U’ suffix either means a core charge or a Used product. Last I heard it takes months to get the transmission too.
That’s it here. But like many parts cheaper from the dealer than ECS: