I went to get my oil changed the other day and the tech was rambling on about some kind of fluid that needed to be changed to handle my all-wheel drive. He said that it should be changed every 30K. Does anyone know what he's talking about?

 

It's all spelled out in your owner's manual. Start there. If that's not enough, look in the Tech/General Questions forum.

 

Front differential: gear oil
Read differential: gear oil
Transfer Case: ATF

Make sure he uses gear oil of the correct grade and viscosity, and the correct ATF.

 

Thank you for actually being helpful.

 

Maintenance intervals have always, at least in the 30+ (?) years I've been on forums, been a source of great debate.

Driving Japanese cars for most of these years I've always defaulted to the owner's manual as the manufacturer knows how the vehicle should be maintained. While the arguments are valid that fluids could be changed with greater frequency, there is cost/benefit to consider so while changing engine oil every day would ensure the least amount of wear on the engine, it wouldn't be cost effective - there is a happy medium between cost and benefits.

Additionally, I worked in car dealerships (import) for >10 years and the service department is held accountable to generating a profit to the dealership so when a mechanic states the fluid needs to be changed every 30k miles, I question whether he/she knows this to be factual or is recommending additional work to generate revenue.

Below I've included the maintenance requirement Infiniti recommends for my 2011 G37x (2012 is the same) and they indicate the fluid should be inspected every 12 months/15k miles. However, there is a call out (Note (1)) stating the fluid needs to be changed every 30k miles if towing a trailer or driving on rough/muddy roads.

Ultimately you need to do what feels right for you taking the manufacturer's recommendations into consideration and knowing your personal driving habits.

-Eric

Edit: Many new owners do change fluids as they don't know the history of the vehicle or the previous owner's driving habits. This could certainly be considered a "best practice" for peace of mind.

 

Too much to read... need the short version

 

So 7AT trans fluid is maintenance free, but diff oil still needs to be changed at 15K and 30K.

I recently got my AWD Q used at 30K and I'm not sure its been done...that is a dealership repair, no?

 

Every 30k miles should be fine.

 

Personally I would not go by this recommendation and plan on changing my trans fluid every 30-60k miles which may be overkill but hopefully preserve the tranny. Mine definitely felt smoother after getting my fluid changed at about 80k miles but not sure if previous owner changed it at all.