Transmission Fix

[teammootracer]

I've read that the 99-00 RX300 transmissions have a smaller then needed ATF pump, and that the 01-03's received a larger pump. Has anyone tried to install a 01-03 atf pump in a 99-00? Is the pump difficult to replace(internal)?

[RX in NC]

The pump is not the most significant transmission problem on the early RX models. It's the poorly designed and fabricated planetary gears. Search this forum using "RX300 planetary gears" as your search phrase and look for Lenore's threads about this issue from the 2008/2009 timeframe. After reading the threads, you'll have a much better understanding of the size and scope of the problem....

[tmastres]

I've read that the 99-00 RX300 transmissions have a smaller then needed ATF pump, and that the 01-03's received a larger pump. Has anyone tried to install a 01-03 atf pump in a 99-00? Is the pump difficult to replace(internal)?

I believe that there were some changes to the trans for the 01-03 model year Rx300's . There are so many post regarding trans problems over the years it may take months to find the ones that reference the changes but the last time this row came up (yes, there is quite a debate on this issue), I recall NHTSA numbers that showed statistically that the 99/00 versions had noticeably more failures than the 01-03 versions. Some claim the tranny's are exactly the same, some say there were improvements in the 01-03 model years. Take a look and decide for yourself.

As for the pump, I don't think that was the only issue, so replacing it may just be a lot of work for naught.

As mentioned by RX above, you'll need t set aside some time and mine the archive on this forum, there's a lot of info in there.