05 Auto, weird issue at 3rd gear, need change auto tranny fluid?
 

Hi, I got a 05 RX8, auto. Car just hit 70K. Replaced engine with <10K miles on it.

The issue I have is, when drive in auto mode(D position), when I slowly accelerate the car, when it gears up to 3, it will have a funny response. The feeling is the car rapidly drag you back and forth, kinda like it change gears rapidly between 2nd/3rd gear or 3rd/4th. I only notice this issue when use "D", when switch to "M"(manual mode), the issue is gone. Also, the issue only appears when I accelerate very slowly.

Since it hits 70K and the previous report never mentioned any automatic transmission fluid flush/change, I was wondering if that is the issue.

After doing some research I found ATF change is a quite pricy job. The fluid per se costs like 100USD, and it's way not as simple as manual '8. After doing some research some ppl suggest never change ATF or change it at 100K miles. Some ppl suggest change every 30k or at 60K miles.

So I go and checked my tranny fluid today, it's full, very clear on the dipsticker, only a little brownish color at the tip. When wiped by a paper towel, it's like a very light reddish or brownish color(like brand new engine oil, I was in dark so not so sure). I don't know what's burning smell, but it smells like a hot metal(car is fully warmed up).

So I don't know what to do now. Is the issue related to the tranny fluid? Do I need to change the tranny fluid(assuming the previous owner never did it.)

My local dealer asks for 260 for flush tranny, :eek:scares me a lot. I saved my ass off to replaced all the ignition system, general tune-ups, and anyother work I can do myself. 260USD is definitely more than I could afford now

Look forward to your suggestions

Thanks a ton in advance!!!

I suggest you have the transmission flushed. Check out the price at a local transmission shop; $260 seems kinda high.

Like any other lubricant, ATF wears out eventually (viscosity, contaminants, etc), especially under the heat and load of an automatic transmission. The notion of a "sealed for life" transmission is ridiculous.

You are lucky in that you have a dipstick on your 4AT. The later 6AT has no dipstick, it has an overflow port in the pan which makes checking the fluid much more difficult. Did you check your fluid level according to the book (motor running, normal operating temperature, transmission in park) ?

I would definitely get the transmission fluid flushed & changed. Make sure whoever does this uses the proper fluid specification (JWS3309, or equivalent).
Like this:

http://www.mobiloil.com/USA-English/..._ATF_3309.aspx

Thanks all, I have one more question, do you guys suggest I should replace the transmission filter? I cannot find that part from any vendor here, I also cannot find any part number from the tech manual or owner manual. Actually those manuals never mentioned there is a tranny filter anywhere. But i called the dealer and they said they will replace the filter and fluid.

So is there a filter? do I need to replace it? Where can I buy the filter?

Thanks

My manual says the fluid is "ATF mIII or equivalent like Dexron III", so I don't know if that the fluid you mentioned.

http://shop.advanceautoparts.com/web...RPTRANAMS_____

would this be compatible. this is the cheapest one I can find

I couldn't find a listing for it either! Call the dealer's "Parts" counter and see what they have for a filter.

There is some sort of screen, but it isn't well documented in most places. See if the dealer has a listing for it. It is more involved to change the fluid AND screen, as the pan must be dropped. The critical part is changing/flushing the old fluid, which can be done without dropping the pan.