Hello all. I have a 2003 G35 coupe.

So my tranny needs to be replaced, I know that part already. What I need help with is finding the replacement tranny. I've been searching around and found a lot on Ebay, however when I finally decided on the tranny I wanted to buy, the place I called asked me "what was the model year?". When I told them it was 05/03 (May 2003), they said the tranny they had was a 2004 and it was not going to fit in my car. I was really confused because I thought they were all the same type of tranny from 2003-04. Now I'm not an expert (obviously) but the guy I spoke to did not want to give me details when I asked why it wouldn't fit. All he said was it wasn't going to fit and I can still buy it if I wanted but I'd be wasting my money. Can anyone help me with confirming if I have to buy the specific month and year tranny to match my car? It's getting worse the longer I drive the car and I don't have a second car so I'm definitely walking on egg shells right now.

 

If it's a 6MT, I think they had the same casings but different internals throughout the model run. Cleric is an expert on that, so I'd PM him for info. The 5AT was the same Jatco unit every year. IIRC the "CD009" was the best iteration of the 6MT.

 

6MT you can throw in any tranny.

5AT you can throw in any tranny if you swap the existing valve body and TCM to the replacement tranny. Look at your transmission, there are two styles and you probably have 3 green harnesses, the other newer tranny has a single large grey one.

The transmission internals are basically the same, a few parts revisions but the only true differences was the TCM and valve body and you can swap yours into any other G35 or 350Z 5AT tranny. If you find one with the correct harness but don't want to (or can't due to mechanical failure) swap the valve body and TCM you MIGHT need to have it reprogrammed by Nissan. Some folks require it and some don't.

Just out of curiosity have you gotten a quote from a local shop to rebuild your existing transmission? It's usually a reasonable price if you pull the tranny yourself. If you only have one vehicle factor in the price to rent a car or truck for a week or so.

From experience, you can fit a transmission in the back seat of a cheap rental sedan, just wrap it in plastic so you don't get oil on anything lol.

 

Oh yea, I forgot to mention it was a 5AT. The quote I got from the shop to rebuild it was a little over $4000 and change. This is why I was seeking a replacement on Ebay etc.

 

I was able to get a brand new transmission (only vehicle and only dealership within an hour of my house/college, needed it back on the road and figured if I was upgrading stuff why not) for $4400 at an Infiniti dealership with only knowing the service manager for a few months. If you're doing a rebuild for $4000, I'd expect some internal upgrades at that point, not back to OEM specs. If you could convince them to install a Transgo kit at the same time, I'd consider that a meh deal.

 

If I was in your shoes I'd seriously consider buying another car and selling the G. It might be a better option than putting $4000 into a car that's probably worth right at that number. Your budget would be $4000 plus what you could get for the current G, let's say $2500, and you could probably get something else in better shape for $6500, including another G, if you shop around.

Just a thought...

 

If it were me, I'd plop in a 100k mile transmission off of ebay for $500 total including new fluid and install a TransGo kit while I was at it. Then start to disassembly the old 5at for fun lol.

 

I'd get another quote. That's how much it costs to rebuild the transmission in my 2500HD which is FAR more expensive than the components in the G.

If that price included removing and installing the transmission then it sounds about right since they add on about 10 hours of labor.

 

Out of curiosity how many miles did you have on it? And did you change your atf?
I have a 04 with 172k.
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It has 170k as of this morning. I bought it used though so I didn't do a tranny flush but I did changed the aft sometime around 2017....if that makes sense. I'm not a gearhead so pardon me if I confuse any terms in advance, but I have definitely been learning a lot in the past few years. My mechanic was saying it would be less problematic for me to change over to a manual transmission but I'm thinking with the cost of the parts and me being in college.....yea that's gonna be way more expensive. I would prefer it though because manuals are so much more fun to drive.

 

yea that was the quote to remove and install the other tranny.

 

That was (and may still be) the plan, if I could get a decent one for that price. so far the available ATs are $800+ with about 80k. the less expensive ones are above 150k and that wouldn't make sense to me since mine is 170k and giving trouble.

 

I would do that, but I'm in college and the funds aren't quite there as yet. I can't even sell it because it's super modified and KBB is rating it at <$2000 so I wouldn't even be able to sell it for a good profit to make do for another. So I figured I'd just spend this $1000+ to change the tranny and keep it moving

 

Get another auto tranny. By the time you buy a 6MT, a flywheel and clutch, and the 6MT ECM you're going to he WAAAAY more than just sourcing a used 5AT.

 

Doing a conversion will always cost more than doing a simple swap. Go to other mechanics. I left one because they did sloppy work. Are you leaking fluid? Slipping? Whats your fluid level at? Also never do a flush, youll get particles where you dont want it. Drain, measure what comes out, refill. Drive a bit, change it again. I hope you used Nissan J or S matic
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