From the APS Precision Transmissions website:

"Mopar ATF+4 is a World Class Fluid having exceptional durability. However, the red dye used in ATF+4 is not permanent; as the fluid ages it may become darker or appear brown in color. The ATF+4 also has a unique odor that may change with age. With ATF+4 fluid, color and odor are no longer indicators of fluid condition and do not support a fluid change. Use 45K miles or 3 Years as your guide also replace filter and have bands adjusted at service intervals."

 

If it is shifting fine, doing a light service (just a drain and filter change) should not hurt anything...just don't go flushing it. I would change it AND save for a new one down the road. ATF turning brown and smelling slightly burnt are not necessarily bad signs. It normally just means the fluid needs to be changed. If it turns black and smells really burnt, you have issues. You can buy any licensed ATF+4 (all ATF+4 is the same blend) and a filter kit for around $40 for a light service.

http://www.centerforqa.com/licensedatf4brands.html

 

My 46RE recently started slipping on the 3-4 shift and ultimately lost all gears. Further, the fluid was very dark even after just 200 miles from a fluid change.

Upon rebuild, I noticed that all the clutches and bands looked very good. The ultimate cause was the overrunning clutch assembly (needle bearings) in the OD unit failed.

Further, I am just about finished with the rebuild for less than $500.

I say all this to point out that a) the burnt fluid is never good and something is going bad inside your tranny and b) if you rebuild it yourself it can be very cheap.

I am putting together a help manual with lots of pics for the rebuild. When I am done, I will post on here.

 

I concur. The 47RE without some sort of unlikely adapter will not bolt up to a V8.