2007 toyota matrix I have a growling noise more noticeable at the slower speeds; what could be the problem

SOURCE: Toyota Prius 2008 - Transmission or or fluid?

Here is the answer that you are looking for: Never.
The auto trans fluid in a Prius is what we call "World Spec", and never needs to be changed. Why? Because the Prius trans fluid is not used for hydraulic pressure or cooling the ATF fluid due to the lack of the aforementioned hydraulic pressure. All that the ATF does is perform a "lubrication" function. As long as there is no contamination of the fluid (such as being in a flood), do not bother with it.
Regards
Toyota Ed
Prius Master Tech

SOURCE: When do I change the transmission fluid in my 2003 Highlander?

If the fluid smells burnt or is black, replace fluid. Manufacturer suggests that you inspect it at every 30,000 mile interval. I would suggest having it flushed every 75,000 miles as a normal maintenence.

SOURCE: Noise (vibration) when turning right

That sounds like a left front wheel bearing gone bad My friend.. turning right transfers weight to the left side and it probably has a roar similar to a turbo fan jet.. Try it and lemmie know.. thank you

SOURCE: 2007 Toyota 4 runner transmission filter and fluid change??

at 50,000 miles there is really no need. i would wait and save up that money and do a transmission flush 7- 10 quarts of toyota f-type fluid can be costly but a flush removes all of the fluid and garnish along with any fine shavings (normal wear and tear) out of the tranny and replaces it with new clean fluid. normal intervals would be at about 80-100,000 miles. you should be able to find preventative maintenance schedules in your owners manual. if not any repair facility would have it on their computer.

SOURCE: 2002 toyota sienna change transmission fluid and

The drain plug is on the bottom of the transmission. Its torqued to 49 nM.
1. Remove tranny oil pan drain plug
2. Drain old fluid (roughly 2-4 quarts)
3. Reinstall drain plug.
4. Measure amount drained in a 99 cent orange juice pitcher from Walmart
5. Pour back the same amount drained using Toyota Type T-IV fluid (available in 1 quart bottles from a Toyota dealer.
6. Start engine and shift slowly through all the gears ending in Park.
7. Check fluid level on the dipstick. Add fluid, if necessary, to bring the level to a point inbetween the COLD and HOT marks on the dipstick.
8. Go for a 20 minute drive and recheck fluid level. Add fluid, if necessary, to bring the level up to,
but not beyond, the upper half of the HOT range on the dipstick.

As in 1973, NO FLUSHING is needed and NO FILTER REPLACEMENT is needed, NO PAN REMOVAL is needed. As, as in 1973 todays Toyotas have a metal mesh filter screen that doesn't ever get clogged except in rare cases of transmission operational abuse, including failure to ever change the fluid for 150,000 miles or more.