Greetings,
Sorry to re-open this can of worms but I'm looking for some information. There are several threads in various newsgroups concerning the effectiveness and safety of a transmission flush. Some folks (myself included) prefer dropping the pan, cleaning it out and changing the filter while others believe properly flushing the tranny is OK.
Now here's my question -
Since I have an '04 with the Allison tranny (which has an external filter) wouldn't it be essentially the same if I had the tranny flushed at the dealer then changed the spin-on filter afterwards as compared to dropping the pan to change the fluid then changing the spin-on filter? In fact, I wouldn't even have to drop the pan since the Allison's pan already has a drain plug in it from the factory.
I'm looking for two things: Whichever would be the best and least expensive for my tranny. I understand that just by draining the fluid from the pan thru the plug doesn't get all the fluid out. Does a flush exchange all of the fluid?
Thanks for any input.
Cheers - Jonathan