F25 X3 30d first time BMW owner - transfer case issues?

[Benji]

In my continued quest to get everyone around me into a BMW, I recently got a brother of a mate into a F25 30d pre LCI M Sport, white with white leather, 160,000km, very nice spec FSH, well looked after, matching good tyres etc. After an extensive test drive, which specifically tested that 4wd is working, we struck a deal and took the car home. I was very impressed with the effortless power delivery of the 30d and general refinement and quality of the car with only a few minor cosmetic issues.



As a first step in preventative maintenance, I recommended that he take the car to ZF for a transmission service. ZF came back saying the car needs a new transfer case due to an "imbalance in the drive chain". There are no symptoms of shuddering or weird noises from the transmission. I am struggling to believe this diagnoses, but ZF are a trusted vendor...Are there any thoughts or advice on this? Change the oil and send it?

As a second round of preventative maintenance, I recommended he delete the DPF, swirflaps and EGR. I spoke to Sherwin at Xcede who can disable EGR and swirflaps via coding, but does this not still leave the failure prone hardware in place and kinda defeats the purpose?

Is there anything else we should look at? Crank pulley I believe should also be inspected

 

[tdi_stig]

Common issues on the 30d.
|
EGR gets dirty. Clean it and delete it.
Intake gets dirty due to EGR. Clean it and delete EGR.
Swirl flaps. Can be software coded, but like you said, the flaps remain. Best is to remove them so they don't fall into engine.
DPF can get clogged. Get downpipe and delete from software to prevent error.
Control arm bushes can get worn, if guys replace and not follow correct procedure they will fail prematurely.
Steering rack bush gets worn and can cause a rattle when going over bumps.

 

[Solo Man]

Remove the swirl flaps. Easy on that motor. On my N47n motor (2013 F10 520d) i bought a new inlet manifold gasket (Rheinz) which already had the swirl flaps deleted thus covering all the holes left if one does remove the swirl flaps. Also get an egr delete kit and fit that asap as on my son's F25 3l d the egr got stuck in the open position causing holes to burn in the inlet manifold. So get rid of the egr. Remove or replace the cat (sell the innards for about R2k) with a straight pipe. If it was my car i would just drive the car without worrying to much about the transfer case. The suspension i will leave as is untill you hear knocking sounds. On my son's car i replaced the lower control arms when the ball joints became noisy. Had a front wheel bearing fail on that car when i still had it before trading it to my son. I have not heard transfer case issues on the F25 but some on the E83. As i said, would not worry about it, fix it when it breaks! This is my advice from experience. Your choice though!