E53 2005 3.0d - Possible gearbox issue

[neilt]

I've had a look through the searches and can't quite find the issue i'm having so hopefully I can explain it.

A couple of weeks ago I left home (cold engine), and along the side road from my house it felt like the handbrake was on (25mph), something just didnt seem right. I had been towing a 500kg trailer the day before, and thought it was in my mind. At the end of the road I turned onto the main road and it seemed fine.

Fast forward to this weekend. I left home for a longer trip. as I climbed up the the dual carriageway from my town I put my foot down to pass a car, it kicked down and at about 65mph I lifted off slightly as it was holding 4th gear, as I did this it started to make a droning sound which stopped if I put my foot down again, it was at about 3000rpm. I couldn't get it to change gear (although thats not unheard of when going uphill), and also, it seemed that the torque lockup wasn't working.
The noise was bad enough that my wife mentioned it. She then went on to say that she had a problem driving home from work the day before where it felt like the handbrake was on!!!

So, its not only me that has noticed this, so I am guessing there is an issue starting.

Some history of the car. Its done 102k miles, and was owned by my dad from new, until I bought it last year with 88k. At 40k'ish miles (when it was 2.5 years old) it had new gearbox oil by BMW as there was a strange squeak when it changed from 3rd to 4th, BMW said it was a known issue and used a different oil.
Its done very little towing, I have towed my race car a few times (1500kg total trailer/car weight), plus the 500kg box trailer 2 weeks ago.

[neilt]

Having done some more investigation on the internet, it seems the Torque convertor can be an issue on the ZF gearbox, and does give the droning sound that I mentioned.... should I be worried? 

[Adam1411]

Im not too sure on the ZF box and torque converter but on mine (GM) the torque converter is the one to go 1st and then from that it destroys the gearbox the 1st thing i did was drop the oil to check for metal fragments that would be my 1st port of call

[Y13HYA]

i just had my gearbox done, but luckily my issue was not the torque converter. maybe worth getting a auto tran specialist to look at it.

[neilt]

I spoke to a local well known Auto Gearbox specialist just now. Luckily they have a ZF specialist there, who obviously knew his stuff as he mentioned the knocking into 1st gear issue.

His first comment was that most of the X5's that go in with the ZF gearbox have suffered electrical issues rather than mechanical (unlike the BMW engined Range Rover which suffers more mechanical issues).

He suggested I first get a OBD check to make sure the MAF and EGR are ok as they see issues when these are not 100% and send wrong signals to the gearbox. This remined me that I did have a low resistance on MAF fault when it was plugged in a few months back, so first thing I think I will do is see if that error has come back again...... £230 for a new Bosch MAF!!  :blink:

[Dimsum]

Hi Neilt

How did you get on with this problem?