# Changing the ATF

**URL:** <https://community.cartalk.com/t/changing-the-atf/120647>\
**Category:** Maintenance/Repairs\
**Tags:** prius, toyota\
**Created:** [July 8, 2018, 6:11pm UTC](https://community.cartalk.com/t/changing-the-atf/120647 "2018-07-08T18:11:35Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![manhal](https://avatars.discourse-cdn.com/v4/letter/m/c5a1d2/32.png) [@manhal](https://community.cartalk.com/u/manhal)\
**Post date:** [July 8, 2018, 6:11pm UTC](https://community.cartalk.com/t/changing-the-atf/120647/1 "2018-07-08T18:11:35Z")

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Is it recommended to change the transmission fluid after certain period for the prius 3rd gen.  
Toyota’s user manual don’t mention changing the ATF .

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [July 8, 2018, 10:53pm UTC](https://community.cartalk.com/t/changing-the-atf/120647/2 "2018-07-08T22:53:04Z")

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For long automatic transmission life, it’s recommended to have transmission fluid serviced every 30,000 miles.

Tester

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**Author:** ![oldtimer-11](https://avatars.discourse-cdn.com/v4/letter/o/e79b87/32.png) [@oldtimer-11](https://community.cartalk.com/u/oldtimer-11)\
**Post date:** [July 8, 2018, 11:30pm UTC](https://community.cartalk.com/t/changing-the-atf/120647/3 "2018-07-08T23:30:38Z")

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Toyota claims their transmissions need no service for the life of the car. If you expect the life of the car to be more than 100,000 miles, I would have it serviced. Only with genuine Toyota transmission fluid. If they tell you they are going to use some other fluid with an additive package to make it compatible with Toyota transmissions, get out of there as fast as you can and don’t go back.

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**Author:** ![insightful](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/insightful/32/2732_2.png) [@insightful](https://community.cartalk.com/u/insightful)\
**Post date:** [July 9, 2018, 1:41am UTC](https://community.cartalk.com/t/changing-the-atf/120647/4 "2018-07-09T01:41:15Z")

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As near as I can tell, your Prius transmission has two motor-generators, one planetary gear set plus a one one-way clutch if it’s a Prius Prime, i.e., no conventional hydraulically operated clutches. The fluid should last a very long time.

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**Author:** ![auto-owner](https://avatars.discourse-cdn.com/v4/letter/a/50afbb/32.png) [@auto-owner](https://community.cartalk.com/u/auto-owner)\
**Post date:** [July 10, 2018, 12:38am UTC](https://community.cartalk.com/t/changing-the-atf/120647/5 "2018-07-10T00:38:11Z")

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> [@manhal](#):
>
> Toyota’s user manual don’t mention changing the ATF .

Based on the few Prius experiences I’m familiar with, their confidence is well-founded.

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**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [July 10, 2018, 12:48am UTC](https://community.cartalk.com/t/changing-the-atf/120647/6 "2018-07-10T00:48:16Z")

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As @insightful said, you don’t have regurlar ATF. You do have a planetary gear box, so if you choose to have that fluid changed, have the dealer do it to make absolutely sure you get the right stuff in it. Every 50k wouldn’t hurt.