Well, before you know whether you should drain the torque converter or not you need to know if your transmission fluid has ever been changed before. Was the fluid that came out of the pan burnt? Did 4-5 Quarts come out when you drained the pan, or less? How much metal shavings where on your magnet? My father is a regional manager of 4 different Perfection Tires in Washington State and per their policy they cannot drain the torque converter without warning the customer of potential risk. That risk is that if parts of the transmission are being held up by the fluid in the torque converter fall out of place it could ruin your transmission or introduce issues you never had before. Was there a yellow bobber in your pan? If so, the pan had never been dropped, which generally means the fluid has never been changed. If the fluid in your truck has never been changed and it has 185K miles on it, its WAY past due. It's generally accepted that a full drain should be done around every 30K gained miles on the odometer for best results. At 185k miles I wouldn't even entertain a torque converter drain. I would suggest a pan drop w/ filter change every 7K miles until she dies. When you drop the pan, a little over 1/3 of the fluid is renewed with new fluid and that fluid mixes w/ the fluid in the torque converter. My concept is if you do a pan drop every 7k miles w/o draining the torque converter more pure fluids will mix with the older fluids, making a more pure mixture, without risking the destruction of your transmission.
How do I know all this? Well, I did the same thing as you, but I was told by several people, including my father to NOT do a full drain in case my fluid had never been changed in my truck w/ 115K miles on it. I dropped the pan only to find the yellow bobber, indicating my fluid had never been changed. I am not to concerned however because the fluid that drained from the pan was still a brownish redish color, vs a burnt red color, a total of 4-5 quarts drained out, and I had very little metal shavings on my pan magnet.
It's stupid to say "It's not a truck if I doesn't have 4 wheel drive!" Most people who have trucks use them as daily drivers or for hauling and only use 4x4 ~1% of the time. 4x4 trucks have a lot more parts, they're harder to maintain and 4x4 trucks also get ~2MPG less on average City and Highway compared to a 2WD truck...So if anything, 2WD's benefits outweigh 4WD's
Last edited by m3t4lm4n222; 08-15-2012 at 03:29 PM.