Hi!!
I have a 2007 aspen. I have the 07 and 08 owner's manual.

In the 2007, they write to change front and rear axle fluid at 15 000 miles.

In the 2008 manual, they write to VERIFY after each 18 000 miles, and change it if it is a police, taxi, etc vehicul. So, we never have to change it as per this manual

and for the oil change, 2007 is every 3000 miles, and 2008 every 6000 miles...

Why this big difference, for the same Aspen???

Thanks for u'r help!!

Sorry for my english, i'm french

 

i to have same problem if u have got any suggestion from anybody...please tel me thanks in advance....

 

I know the '07 4.7 & '08 4.7 engines are different. From 265hp to 303hp Not sure if the Hemis changed

 

Axle Fluid

I took a look at the owner's manuals for 2007 and 2008. In 2007, the severe service schedule calls for changing the axle fluid every 15k miles. The normal service schedule doesn't even mention it, so even then Chrysler acknowledged that it was only necessary to change it under certain conditions.

For 2008, page 443 of the Owner's Manual requires that the front and rear axle fluid is inspected every 18k miles, and changed if you're "using your vehicle for police, taxi, fleet, off-road or frequent trailer towing". Most of us will never need to change it, or can do so as a just-in-case item from time to time.

I suspect that Chrysler was getting pressure from owners and industry, so they softened the language in 2008 along with tossing the severe service schedule. I had mine changed once at 18k miles (bought the vehicle used), and made sure they used synthetic fluids. I won't be changing it again anytime soon.

Oil Change Interval

Similar to the above, the 2007 manual had severe/normal schedules, and the 2008 version only uses the summary table on page 443. As you mention, they finally dropped the 3,000 mile interval for severe service, but the change was likely more political than mechanical.

With few exceptions, a 6,000 mile oil change interval is more than sufficient for modern engines, especially if you choose to use a synthetic oil. I believe Chrysler pushed the interval to 6,000 miles in response to competition from other auto manufacturers, who nearly universally went to 5,000+ mile intervals around the same time (or sooner). Many makes are now at 7,500 mile intervals, with "severe" service being 5,000 miles. Chrysler is still WAY on the conservative side in hope of making more $$$ on service, IMO.

Incidentally, I think Chrysler is also hammering us on other service items too, and it has probably lost them sales. I just had to change out the spark plugs on my Hemi at 30k. It's ridiculous that Chrysler chose copper plugs in these engines when most other engines go 100k before plugs need to be changed.