Gearbox problems...Software upgrade result...

[Roy2593]

Hi all,

I have had a problem with the gearbox. When i slow down at a junction and come to a stand still the car snatches a bit whilst going into first gear.

Also when going down hill, when i press the brake pedal it will change down a gear when it doesnt really need to, this will cause the car to lunge back!

I have taken the car to 'Trenics' BMW specialist in Queensferry Deeside where they have installed a software upgrade to the gearbox.

It has got rid of the harsh down change,thats gone completely but the snatch into first gear has improved but is still there! Its ok for the first 20 minutes you drive the car when its cold but it then starts doing it when the car has warmed up, but not as noticable before the upgrade! I was wondering if it might be something to do with the transmission fluid? Does it get too hot or something? or has it degraded?
I enquired with Trenics about changing the Transmission fluid and the guy there wasnt really interested and voted against doing it,he said that the fluid was probably the original fluid and the gearbox had got used to that fluid and changing it might be a bad idea!??

Any thoughts about changing the transmission fluid?
Has anyone done this and has it improved any gearbox problems?

Thanks,
Roy.

[X5Sport]

Which version of the X5 have you got and what's the mileage on it?

There have been long debates about the benefits or otherwise of changing the transmission fluids. Some owners report that it is beneficial, others report that all it does is flush the accumulated debris out and the transmission fails shortly afterwards. Have a read on the web and you will quickly see what I mean. The contact at Trenics may be absolutely correct, but it is a personal choice. You may win, you may have no difference or you may precipitate a failure.

Putting in a search using the term ZF 6HP26 and there's a result that actually describes your exact symptoms on an S-type Jaguar which uses the same transmission. The spooky bit is that I only read this an hour or so ago

http://www.thelurch.com/lurching_zf_transmission.htm

[Roy2593]

Hi,

Its a 2005 3.0d sport with 88000 miles.

I have searched various X5 forums and there are mixed feelings about changing the fluid!

Not sure what to do????

Roy.