My gear change used to be smooth but lately  i have noticed a little jerkiness i have replaced rubber driveshaft coupler but that's made no difference, i have read a number of articles regarding replacing transmission fluid , could anybody advise on this .      BMW X3 F25 XDRIVE  AUTO  

Morning Darren

The transmission in your car is made by ZF and is a 6 speed (or should be)

BMW Dealers used to say the transmission is "Sealed for Life" what that really meant was the end of their 3 year warranty responsibility.

ZF actually recommend servicing the transmission between 60,000 kilometres and 100,000 kilometres dependent on use. Sadly on most cars the poor old gearbox is one of the least serviced most abused parts of the car. You don't say how many miles your car has covered or whether there is any evidence the gearbox has ever been serviced. It probably hasn't !!

I would start with a Flush and fluid/filter change a ZF specialist or good Transmission specialist will also check the solenoid operation and upload the latest software.

Worth talking to one before things get worse (they wont get better) a few hundred now is better than rebuild later which would be in the Thousands

Just my thoughts 

Dave

 

 

Thanks Dave,    The car was full BMW service history up to 70,000miles ,   I have changed engine oil every  year since then , my current mileage is  115000,  Iam pretty Shaw there's been no fluid or filter change on the automatic gearbox. 

Morning Darren

I would change the Fluid and filter I put my X5's front on wheel ramps then jack up the rear and put it on axle stands to get it level. Tip make sure you can undo the Fill Plug before draining 

Then its a straight forward job make sure you have a couple of containers to collect the fluid there is quite a lot (or should be) At 115k I would think you should be OK just make sure you get the correct Fluid and filter. The only part you may need help with is the software updates a good Transmission Specialist should help talk to a few.

Dave