Transfer case issue

[boqibama]

It looks pretty common for transfer case problem with X5s around 80,000 miles over the internet, but how much risk we are taking? I am hitting 80,000 soon, scared....

[mrbmwx5]

80k miles i'd be scare at all.
my 150k miles and still run like the beast.

[JCL]

If you keep your tire pressures similar front and rear, you have no reason to worry, IMO. Different rolling radius front and rear will stress the splines.

[rogerkiu]

I am using 255/60/17 tires on front, and 275/55/17 on rear. Is that ok for the transfer box? Thanks for advice.

[TwinsPoppa]

Originally Posted by rogerkiu

I am using 255/60/17 tires on front, and 275/55/17 on rear. Is that ok for the transfer box? Thanks for advice.

IMHO, I think you're okay. The difference in your tire diameters is only 1.75mm.

[rogerkiu]

Originally Posted by TwinsPoppa

IMHO, I think you're okay. The difference in your wheel diameters is only 1.75mm.

Thanks a lot!

[Weasel]

It also makes a little difference in whether you have pre 04 or 04 and up.
03 and earlier have solid connection, those are the ones that get stressed splines with tire diameter differences. 04 and up have x-drive clutches that allow a little extra slip for "tire tolerance logic". The worst you'd get with that is worn clutches in the case.

But either way it goes they don't just fail from age, only when something causes extra stress/wear to it. So you should have nothing to worry about.

[boqibama]

Thanks for the input, I'll keep eyes on tire pressure 24/7...

[boqibama]

by the way, it said in the manual, differential and transfer box fluids are lifetime, does that mean never having them cahnged will be fine?
And how much dealer will charge for transmission fluid change? Thanks

[primetime]

Yes it means you never have to change the fluid... You will get varying answers on this though on here from people's personal preferences. I'm at 103k miles and never changed tranny fluid once.