E46 320d auto box strange issue

[Boxwerx]

Hi all,

I’ve had an issue with my 320d for a while with a ratio monitoring sensor failure. Perfectly driveable with manual override and if it does throw a code a simple key reset does the trick.

However a few weeks back a friend was driving and suddenly lost all gears. The car stinks of gearbox oil but nothing leaking under the car. Now the car won’t go into any gear at all.

I haven’t had a chance to look over it yet, that’s tomorrow’s job but wondered if anyone had a similar issue and whether it was repairable? I have a new box on the way but ideally need to drive the car for the next few days, even if it’s in limp mode!

Thanks!

[Boxwerx]

Also is worth noting that 24hrs before this happened it lost reverse. However after pushing it out of the parking space and giving it an ‘Italian tune up’ it was completely fine again

[Raddee]

Why not get the error codes from the transmission computer, fix the sensor and give it some fresh oil and a filter before throwing a whole new transmission at it?

[Boxwerx]

The sensor is inside the gearbox so if I’m taking it off I’ll just replace it with a known good box. Yes, gear oil is also on the cards.

it was more the symptoms I was checking on whether it’s worth even chasing a fix

[Boxwerx]

So got to the car today and it appears that the shifter mechanism isn’t talking to the gearbox. I can move all positions freely and the numbers change on the dash but there is simply no drive, but strangely I can also start the car in any gear. This suggests to me that the position sensor is the problem. However, the only code I got was p0732 which it has had for the past year.

Ive checked fuses etc and all appears ok. Any further thoughts?

[Boxwerx]

Further update - just tried to check the fluid levels, couldn’t get the full screw out but there are no leaks and the gearbox oil cooler is hot so appears all is ok. On the ramp there is drive but on the ground it will only creep forward.

It sounds like something is loose and not quite catching to give it drive, almost like it’s not gripping the prop shaft properly or something. That said, nothing looks loose underneath.

Further update: towed the car round the yard and now have all forward gears. No reverse and weirdly R and N are also both forward gears now. This car is confusing the hell out of me!!!

[Raddee]

Don't know about R and N issues but about the slipping: you could have torque converter issues which could very well be related to the state of the trans fluid and level.

[Boxwerx]

So the latest in this saga is that we’ve managed to drag the car out of its parking space but there is no free wheel motion on the car in reverse. So basically whatever the situation the wheels simply will not go backwards, regardless of whether it’s running or not.

Ive just seen a video linked below on the x3 Gm box and it appears there is a simple rod that breaks and stops it from selecting different gears. This makes sense on my car because it’s only hot forward gears and drives perfectly fine in all gears. It simply makes no difference where the shifter is positioned.

has anyone else had this?

https://youtu.be/WIqKFZlMJF0