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120K transmission flush or fluid exchange?

11620 Views 7 Replies 6 Participants Last post by  mwr
I just purchased a 2004 fx35 with 117,000 miles on it and the previous owner maintained the vehicle meticulously at infiniti dealership, I pulled the service records and he performed every 30k infiniti dealer service (oil change, transmission fluid change, both air filters, coolant change, throttle body, fuel system, differential fluid, at about $800 each time) aside from the dealer oil changes, etc. I was thinking to do the 120k service early and do the spark plugs (I don't see any records for plugs changed) ,maybe flush engine, and do transmission.

Question is should I flush at this point or just do a full 12 quart drain and fill? Also the transmission from what I learned has no filter, I assume they will just remove the mesh screen, clean, and put back in?

Thanks for any and all responses in advance!
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By "hesitation" are you talking about transmission slip? If so, then yes... I think you might be able to regain the "rocket affect" off the line and when accelerating in 3 gear by fully changing your transmission fluid.

Note: The Gen 1 FX35 and FX 45 (which are the same) trannies are more robust than the 2006+ models. These trannies have a dipstick and a metal mesh screen. So don't replace the screen. And don't use a typical transmission pump exchange unit that will mix new ATF with old ATF... no matter what the mechanic says.

Instead, pull your transmission cooler return line and remove all the old ATF by starting and stopping your engine... every 3-4 quarts of fluid you drain. The process is really easy once you follow these instructions I just created after I flushed my tranny fluid in Jan-2022. Note: I used Valvoline's Max Life ATF and find it's working great vs. the 4x more expensive Nissan Matic S.

Also, don't pay your dealer to change your other differential fluids, because everything is very accessible and easy. Note: The dealer wanted $400 to change my differential fluids, and trans axle fluid in my FX45, but I bought my own fluids and had my local mechanic do it all for $125... with an engine oil change. All these fluids only take 1 hour to do! So don't go to the "Stealer" for theses services.... and you will need to educate you mechanic on which transmission cooler line to pull. I.e., on an FX35 you pull the line on the drivers side, but on my FX45 I pulled the rubber hose to the transmission cooler on the passenger side.

Here's the link you need to learn more: 2004 INFINITI FX45/35 (GEN-1) TRANSMISSION ATF FLUSH...
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