I bought my car with 38,5k on her. So I'm that guy that likes to perform preventative maintenance. I've always felt 40k is a good rule of thumb to change out fluid in an auto. So I've tried to search google. FAQ's here, and there's no real concrete answer. I know there's a cast aluminum pan holding an extra quart for the 5 speed auto. But nothing really for the 7 speed auto. And does our vehicles come with a tranny cooler already? And if so. Should it be upgraded? I've read Infiniti's maintenance schedule. And it looks like all they do is check levels out. Are there any parts to help with beefing up a good tranny now? Shift kits? Solenoids?

My advise is to have the dealer use the flush machine at 60kmi intervals. This, IMO, is not a job you can do at home unless you want to do the drain and fill 10x in order to get the best fluid. If you do this at home without one of those fancy machines that replace fluid as it sucks it out, you'll never get remotely close to 100% new fluid.

Transmission, coolant and both differentials was around $600 last time I did it. IMO, well worth it.

My understanding is that you're not supposed to flush the 7 speed transmission. The proper procedure is to suck it out, which is how my dealer did mine. I'm all for doing my own maintenance, but like Ilya said, you really need to have the dealer perform the transmission service if you have the 7 speed.

armybrat wrote:My understanding is that you're not supposed to flush the 7 speed transmission. The proper procedure is to suck it out, which is how my dealer did mine. I'm all for doing my own maintenance, but like Ilya said, you really need to have the dealer perform the transmission service if you have the 7 speed.

Yeah, I do 99% of my own work because I have air tools, a lift, heated garage, etc. at home...but differential, transmission and coolant...I leave to the pro's. You can probably do coolant and differentials on your own, it's just a messy job which is why I don't. But transmission I wouldn't muck about with.

Sorry I wasn't more clear. My intention was to take it to a reputable transmission shop. That's why I work overtime. So I don't have to wrench on my car like I use to as a young man. And that'll be my main question to the shop if they're able to vacuum out all the old fluid from the transmission. But again. Is there anything we can do to the current auto trannys to beef them up so for arguments sake can handle 400rwhp?

I beat the crap out of my car (it has 83kmi on it now) and my transmission is solid as can be. I also make sure my fluid is changed every 50-60kmi. Never had an issue. I wouldn't worry about a cooler, etc. but to answer your question I don't think the M has a dedicated transmission cooler.

That's good to know. Thanks to you all. So maybe I'll hold off on changing fluid till I get to 50-60k...

Ilya wrote:I beat the crap out of my car (it has 83kmi on it now) and my transmission is solid as can be. I also make sure my fluid is changed every 50-60kmi. Never had an issue. I wouldn't worry about a cooler, etc. but to answer your question I don't think the M has a dedicated transmission cooler.

Actually the transmission fluid cooler is inside the radiator. Refer to the factory service manual TM.pdf located in the M56 Faq section of this forum. If I read this right, the cooler must also be checked when the AT service is done. This manual is very informative check it out...covers everything about this transmission, stuff way over my head LOL.