what tranny do i have

[BLADE]

Hi guys thanks in advance for any help. I have a 2004 olds alero 3.4l with an automatic transmission. what trans do i have the 4t40e or the 4t45e I looked at the tag on the transmission and couldnt get a straight forward answer is there some way to decode the tag. on my 95 berretta its imprinted on the bottom of the pan 4t60e no problem. But the alero is not like that. And am I ok with dextron III ATF or is it ok to put synthetic oil in these. Im open to all options. My haynes manual says dextron III.

[Joelfke]

According to my alldata. you have a 4t40e. it came from factory with dexron 3 but GM has bulletins out that state you can put dexron 6 in with no issues

[robertisaar]

alldata is saying 4T40, but i could have sworn that that the 3.4 n-bodies went to the 4T45....

https://www.compnine.com/vid.php

throw your VIN in that, and see which RPO comes up. the trans RPOs almost always start with M, so you could skip down to there.

[BLADE]

ok went to pick up a tranny filter at store and he asked me if i had a 12 bolt pan i didnt know so i left. Counted it today and came up with a 14 bolt pan. so im starting to think since i have 2 more bolts do i have the 4t45e can anyone confirm this.

[robertisaar]

i counted 14 bolts on a trans pan gasket on a 4T40.

just look at your RPO codes...

MN4 is the 4T40
MN5 is the 4T45

in 2001 at least, a 3400 alero has a 4T45

[BLADE]

just tried that site it didnt find my vin # thanks for the help though. still havent found a definite answer. just the 12 bolt pan vs. 14 bolt pan just a thought.

[BLADE]

ok i will look for that code on the tag MN4 or MN5

[BLADE]

just looked at the tag it didnt have any of those nombers either. it did say gm of canada i dont know if that was the reason it didnt come up on that site. still at a lose on this one should i call the dealer or something?????

[robertisaar]

are you looking at the tranny tag? look at the bottom of the spare tire cover, and you should see the RPO list. you should see one of the codes there.

[BLADE]

ok i found it on the web site must have typed it in wrong thanks for your help its a 4t45e for my 2004 olds alero 3.4l thats a great site put it in favorites thanks a million

[BLADE]

do you use dextron III or has anyone tried the dextron 6 i didnt even see any at cheaker auto they had dextron III and i think dextron 4 synthetic

[robertisaar]

there is no such animal as dex 4, GM went straight from dexIII to dexVI. IMO, it's worth the cost if the spec sheet is even 50% exagerated.

[BLADE]

ya you are right about dextron VI i wasnt paying attention to the label. what do you mean if the spec sheet is 50% exagrated . Is it ok to use dextron IV in the 4t45e 2004

[robertisaar]

http://www.sandyblogs.com/techlink/2009/05/dexron-vi.html

short version: MUCH improved compared to dexIII, and dexVI is backwards compatible with any other previous Dex fluids.

[BLADE]

so what i get out of it is that dextron IV is backward compatible with dextron III . Thanks for all your help and time robertisaar I learned a great deal about this tranny. So i think that i will try dextron IV.