Transmission Replacement and Longevity Issue
 

Hi all,

We have a 2004 Nissan 350z with an automatic transmission at 140K miles. We had a mechanic check out the car for other issues for a few days and he said the transmission at a full stop sometimes do not start at first gear and throw code several times, which we did not ask for the code. He said that the problem more likely to be the valve body. Checking the price of the valve body. The price is over $1100. The mechanic said it might be best to get a used transmission to replace the old one since there might be other problem with the transmission since it has high mileage on it. Our questions are:
1. How long does a Nissan transmission typically last? Transmissions has not been taken care too well. Previous owner let his kids - teens drive the car for a few years.
2. What is the labor cost for replacing the transmission?
3. Beside getting a transmission from a Junk yard, are there other parts that I need to get for the mechanics to install the transmission?
4. Should we get all new transmission fluids for the replaced transmissions? How much transmission fluid?
5. We see transmission going from $500 to $1000 with similar past mileage? Why are there are such a large delta on transmission prices? What should we be looking at to ensure that we got a good transmission? Will the junk yard give like a 1 year warranty with extra cost?
6. We recently drain and fill the transmission 4 times. Could this have cause the issue? We heard about this, but we done this with our two other cars without any issue in the past?

Thanks,

1. Well cares Nissan engines can last 200-400k miles if not more. That said make sure you get a 2004.5 or newer transmission. Earlier models at least with the stick versions had some issues that were fixed in later years.

2. Labor? The labor cost is what ever your mechanic wants to charge you. I’d say expect $800-$1,500 for labor alone. Best to actually ask yourmechanic.

3. Just the transmission. It should have everything else or be able to pull parts from your old transmission. Another question you should ask your mechanic specifically.

4. Yes. Fluid shouldn’t cost you more than $30... But labor is another story. But since the trans will be out I don’t see it being very labor demanding.

5. The prices will very depending on model, year, miles and condition and parts that come with them. Some will come with the torque converter other will not.. Some come with the ECU which some people will need.. All depends.

6. Why have you drained the fluid 4 times?! Transmission fluid should be changed every 60k miles.. And yes it could be if you used the wrong fluid, not enough fluid or too much. You need to fill it to the proper level.

lol..

@CK32. Thanks for the feedback. We drain the transmissions during the maintenance to change all of the fluids.

Can you elaborate on the 2004.5 or newer transmission? Do I need to find out when the car was built to find the right transmission? If so, how do I find when my car was built?

Looking at Junkyard, I saw the following transmission option for the 2004 Nissan 350Z:
a. AT, from 10/03
b. AT, from 7/03 thru 9/03
c. AT, thru 6/03

When you said 2004.5, do you mean option (a) above? Would other years transmission works better like 2008 or are all the transmissions are the same up to 2008 and we should only care the mileage on that transmission?

Thanks,

Newer Z’s have better transmissions than older ones. 2004.5 is a later 2004. Someone else can come in and give you the exact transmission codes stamped on the transmissions you want to look out for.

I’m not sure if 2008 Z transmissions bolt right up but I’m sure there better than early model ones.

And you don’t need to change the trans fluid that often. Only every 30-60k miles. Unless it’s brand new you change it at the first 15k miles.

Just so everyone knows the approach that we used in choosing the transmission as a replacement for the bad transmission. We winded up matching the transmission to the manufacturing year and month of the car. The junkyard told us to check on manufacturing date for the car which is on the driver door or check with the dealer based on the VIN number. We then provided the car manufacturing date to match the following to the junkyard

a. AT, from 10/03
b. AT, from 7/03 thru 9/03
c. AT, thru 6/03

Searching through their database to find a matching automatic transmission base on the ranges below. We got a few options. Not sure if the transmissions are interchangeable but that is what the junkyard recommend in finding the right transmission. We wanted to avoid any complications. Using the on-line search yield better results on the transmission then calling the junkyard. They will always give you what they have in stock which might have higher mileage and cost more. We were able to get a 60K transmission for $400 + $75 core charge + $98 (3 years parts and labor warranty) and $50 shipping. Prices and inventory varies significantly week to week so check the on-line database often. After the purchase, the week after, we saw a few transmissions with 20K mileage at a fairly low price.

Wish there was a table around interchangeable transmissions and especially details around requirements and implications.

Thanks,

You have a 2004 Z.. You're going to want a 2004 - 2006 automatic transmission. 2003 automatic transmissions have an external TCM. 2004 - 2006 automatic transmissions have an internal TCM. 2007 - 2009 automatic transmissions also have an internal TCM but will not bolt up to your VQ35DE engine because they are made to bolt up to the VQ35HR engine.