Hey everyone,

I'm trying to figure out what maintenance I need to do at 30k miles on my 04 Expy 4x4. From the maintenance guide, I see that I need to replace the fuel filter and engine air filter, no problem. What I'm wondering about is the fluids. The guide says this about tranny fluid change:I know that I have a 4R75W tranny, and the "normal" schedule calls for changing the fluid at 150k miles. That seems like way too long to wait. Same for front axle and transfer case fluid changes. Under the "special operating conditions" section, it generally calls for tranny fluid change every 30k miles and transfer case fluid change at 60k miles, but no mention of front axle.

So, here are my questions:

1) Should I change the tranny fluid every 30k miles and transfer case fluid every 60k miles just to be safe?
2) Is it ok to wait until 150k for the front axle fluid change? Or maybe every 60k miles along with the transfer case?
3) My understanding is I never have to change the rear axle fluid, correct? Unless the rear axle is submerged in water? (that's what the maint guide says)

For the record, I drive mostly in 2WD, only use 4AWD in bad weather (snow) and on dirt roads, and occasionally 4H or 4L when off-road or in deep snow. I don't tow much, but I do have a Thule roof rack always on the roof. Once a week I carry 1-4 bikes up top for short periods, but I don't tow anything or generally rag on my truck. My miles are probably 60% highway (at speed) and 40% city or stop+go traffic.

 

well i would change the engine oil fuel and air filters and tranny fluid and filter 150k is way to long both diff's are filled with synthetic fluid so there is no need to chnage them unless you had them under deep water.