DIY: 2006 BMW X5 3.0i: Front/Rear Diff, MT, Transfer Case Fluids

[StephenVA]

Originally Posted by franccesco30

So after reading this post I decided to call a few shops to see what they would quote me for flushing the fluids. I called two different Curry's Auto service, and to my surprise one told me all fluids are "lifetime" so they won't even service that. The other said that the transfer case uses fluid from the transmission (manual), so they have to flush the transmission as well. I was only planning on doing the front/rear differentials and the transfer case, so I'm a bit confused now. I think I will trust my independent mechanic and buy the fluids and have him change them. Any suggestions? I'm in Alexandria Virginia by the way

Do you want to do it yourself? Or have a shop do it for you?
Suggestions: If you want to do it yourself? PM Email me as I am in North Arlington
Do It for You: Gary Martin MotorSports in Alex near Home Depot
Martin Motorsports
460a S Pickett St
Alexandria, VA 22304-4706
(703) 823-9735

He is a BMW guy and owns E39 M5, E53 X5, plus a herd of others. Tell him Stephen sent you as I have known Gary for some 20+ years. He has worked on some of my stuff over the years.

[ny x5 guy]

I just had a highly recommended independent shop in northern NJ change out my Transmission (manual) fluid, transfer case fluid (non x drive), and front and rear diff fluids. The man said there's a tag on the casings indicating what type of fluid to use. He used synthetic gear oils conforming to the oem spec. I noticed a nice improvement in overall smoothness of the shifting. Not a huge difference, subtle. Like it slips into gear a little smoother. My vehicle is a '03, entered service in 1/04, has 46,000 miles now. Figured after 10 years good to change it even though the miles are low. The man also adjusted my handbrake. Cost me sub $200 altogether.

Now I am wondering if I should put in a new serpentine belt and a/c belt, but haven't had a chance to eyeball them myself. My guy told me they looked ok. Just thinking I don't know when they were changed and they aren't that expensive, so that's next on my to do list.

[Ricky Bobby]

The MT and the transfer case have two distinctly different fluid holding capacities, fluids are not shared. Brake and clutch fluid is shared however,

[franccesco30]

Thanks RB,

Considering my 2001 E53 has 151K I'll leave the MT Fluid as is, but will proceed with the transfer case fluid. MT shifts fine but I want to do the transfer case anyway, so I'll post if I feel any difference.

Thanks for your input.

Cheers

Francisco

[bcredliner]

I am all about performance but in the case of the differential, transmission and transfer case durability is my priority. Since the original fluids have been fine for so many miles I don't use anything else. What am I missing?

[Doru]

Originally Posted by bcredliner

I am all about performance but in the case of the differential, transmission and transfer case durability is my priority. Since the original fluids have been fine for so many miles I don't use anything else. What am I missing?

Fluids have a lifespan. Some longer, some shorter. In the case of front & rear diffs, they can last quite a while, and in Cam's DYI you can see clearly those fluids still looked good.
For the transfer case, that's a different story. Even BMW has a lifespan put on that one, which I believe is around 60-100 K's. And the TIS also specifies the adaptation values of the TC should be reset after changing that fluid. When I changed it last year, while resetting the adaptation values you cloud hear clearly how the TC was doing it's thing.
Same with the Servotronics (if you have the N62) - once off, they have to be reset after installing them back.

[bcredliner]

Originally Posted by Doru

Fluids have a lifespan. Some longer, some shorter. In the case of front & rear diffs, they can last quite a while, and in Cam's DYI you can see clearly those fluids still looked good.
For the transfer case, that's a different story. Even BMW has a lifespan put on that one, which I believe is around 60-100 K's. And the TIS also specifies the adaptation values of the TC should be reset after changing that fluid. When I changed it last year, while resetting the adaptation values you cloud hear clearly how the TC was doing it's thing.
Same with the Servotronics (if you have the N62) - once off, they have to be reset after installing them back.

Not saying I don't think the fluids should be changed, I change them even the transmission fluid. I don't see why I would want to replace the OE fluids with a different brand when the original fluid has done a good job and I don't know for sure that other fluids even those I swear by would be better in these applications. Seems to me I have no better than a 50/50 chance that going to another brand is better.

[Ricky Bobby]

What shop are you using in NNJ just wondering?

[Ricky Bobby]

Btw at Francisco,

Unlike AT fluid and such, your MT will benefit from a fluid change at any mileage even though yours is higher. Change it out if you are doing diffs and transfer case!

[ny x5 guy]

I used Europcar Service, Morristown, NJ.