Has my gearbox melted down ?????
 

Hi, I've a 2001 4.4i (80,000 miles) and the gearbox has just gone into fail safe mode (meaning stuck in auto in 4th and reverse only) but keeps swithching back to normal ever now and then ? I have checked gearbox oil and it is black and burnt ! my mate read the fault code for me and it reads FAILED PRESSURE REGULATOR has anyone else had this problem and is there anythink that i can do apart from replacing the complete box !!! BMW say new box £3000, my nearest trusted gearbox specialist quoted £1700 for rebuild !
Any info would be great.........
HELP.:rolleyes:

I would say that you could replace the pressure regulator located in the valve body, it's (ZF#0501 210 060 - Pressure Regulator) it's located at page 34 - 51.260 in the ZF Parts Catalog. It could also be the pistons and parts related to that part in the valve body, depending on the condition of the valve body it may perhaps also be a good time at doing a valve body rebuild yourself...

HOWEVER having black and burnt fluid tells me the clutch packs have been slipping, most likely due to insufficient pressure to the clutch packs, which means you've most likely burnt or worn them out. Not a good sign for a healthy gearbox.

My F Clutch Pack Piston was blown and it burnt out the friction material in the clutch pack due to the slippage. I didn't want to pay the amount of money that BMW or any shop wanted to fix my transmission ($4,500 to $6, 000CAD) so I did it myself. You can have a look at my post here.

If you just replace the pressure regulator I would recommend flushing out the trans fluid, and I suppose you could just continue driving it until it does fail completely... Let me know how it goes for you!

Thankyou for the reply what can I say spot on, have printed out info and will look into it but since I posted the thread the gearbox has run like a dream ???? Is this just lulling me into a false sense of security ???

What ever did happend with your trans?

my tranny did the same thing, 1st it was hard down shifting then failsafe mode then tranny gave in. It at the shop right now and its getting rebuilt and they quoted me 4300 to rebuild it. My X is a 2001 205000km when she blew.

time to trader to the stealer

:thumbup: Well sometime later the car came to a complete stop with all the warning lights and airbag lights lit up like the starship enterprise ! to find that the alternator(water cooled at a mer £900) was faulty and not giving the correct volts to anything and the first to notice this was the gearbox. So everthing is hunky doorie now but would not recommend changing watercooled alternator to everyone !
:nanana: so saved a packet on not replacing gearbox but did replace fluids as running on failsafe pushed the limits of the oil !!!

PLS tell us more about the water cooled Alt?

Apparently, the 4.4ii V8 has water cooled alternator:
http://www.realoem.com/bmw/showparts...81&hg=12&fg=20

This reminds me that I need to change battery on my X5. Good to hear that OP got his problem solved.

BMW is kinda finicky, my 535i had one incident of trans fail-save induced by low voltage. (yep my 535i was only 2 weeks, went to vacation right after delivery for 1 week then fail-save engine reduce power, never again).
You'd think transmission is not related to alternator.:dunno: