I know this is a little off topic for this newsgroup, but this group has
people with expertise in about any field pertaining to vehicles. The 4L30E
is used in a couple GM cars, as well as the Honda Passport, Isuzu Rodeo and
I need to change the AT fluid and filter in my passport with the 4L30E
transmission. The shop manual says purchase a transmission fluid
thermometer from you local parts counter before attempting this or serious
damage may be done to your transmission. It has no dip stick, so fluid has
to be pumped in through the drain plug or overflow check hole. Is it really
so critical that you have to check the temp of the fluid before adding more.
This seem like a lot of Bull to me, but I am not a professional like some of
Would like to hear what some of you transmission guys think about this. Do
you know of another safe way to check it without thermometer?