Ok so its been very quiet on the q45 side a things when it comes to mods anyway n all about moddin so I figured I'd share my progress.. I can't recall where I read it but when I'm bored I look thru old posts looking for inspiration lol.. So I read some where on here that n fx45 diff is a direct fit with the f50 q45 good info to know but being that I had already swaped my diff with 1 from a 2003 m45 3.13 ratio I was in no rush to get back under there.. in comes ebay i come across a diff from fx35 very low price, I do some research n the fx35 n 45 use the same diff so I buy it.
Now once in my possession I sit both diff side by side seeing that I still have my original 2002 q45 diff I noticed they are almost exactly the same only difference is the part that connects to the drive shaft is different but its only connect by one bolt so I just swaped that out wit the one from my original diff and also the connecting stud at the rear is a lil bigger so the original bolt would not fit I called up infiniti n for the grand total of 1.97 I ordered the correct bolt now with that in place I was ready to rock and roll. N this time around I remembered to drain n refill gear oil wit mobile 1 b4 I put it in smart because las time I waited till I put it in to remember to change the gear oil not not so smart lol. Not that its much harder but it is that much easier with it being out already no pump needed.. the removal n install wasn't that bad being as this was my second go around it helps to have n extra pair a hands 2 jack stands n a 10 ton jack n the rest was history.. no pics but it's not much of job that really requires pics..
Now the the good stuff. She feels amazing idk y they didn't originally put in a 3.69 ratio diff in this thing i jerk my whole body every time i step on it my off the line is crazy lol then again I also have a few mods so my car I far from stock but this diff made a huge difference on the seat a my pants dyno lol.. I was impressed with the m45 3.13 diff but this 3.69 ratio is where it's at.. I was goin to try for the lsd diff out the g37 but those were more pricy but for the same ratio 3.69 I'm good with the fx35 diff..
N ps I have 2 spear diffs layin around now a 2.97 out of my 2002 q45 and a 3.13 out of a 2003 m45 I plan on putting them on ebay when I get a chance but if theirs any interest in here feel free to shoot me a pm I won't ask much for them.

Awesome to know what other mods can be done to improve results on the caboose dyno!

Got pics or video links by chance?

Nah no pics or video of the job as it was pretty straight forward so didn't bother but when I get a chance I will post a video of me doing a couple of 0 to 60 runs... but I do have a question for u are u familiar with the p1716 code? that's wat it jus started thowring a few days after I made the change I did some research n it points to the turbine revolution sensor not few very posts on it i looked it up in the service manual not too much help it just talks about how to check it with a consult 2.. it still shifts fine but every time I clear that code it comed back after a few mins of driving.. it seems as that sensor is in the valve body do u think i would need to replace that sensor? dealer quoted 190 for the part.

Those 0-60s will do, we take any excitement we can get.

Not too many posts that I have seen. There was one on the M45 subforum but unfortunately as we sometimes suffer, no updates from the OP.
What happens if you shift manually and hold the max at 4th gear or 3rd gear?

Okay so I just took it out for a spin n it shifts thru gears fine in manual mode but when I hold it 3rd or 4th it's kicks me out of manual mode and goes back into D only way to get back in to manual is to turn the car off and turn it back on again.. wat does this means? Am I having transmission problems here should I shoot my self now or later? Lol.. it's starting to seem like I may have to open up the pan n take a look at the valve body.. what are your thoughts?

...when I hold it 3rd or 4th it's kicks me out of manual mode and goes back into D

Explain this to me. If you pushed the stick to the manual shift side, and have bumped it up until the instrument cluster shows number 3 or 4, how can it go back to D? The instrument cluster actually says D while the selector is still stuck in the manual gate?

Yes that's exactly wat happen, when holding in 3rd or 4th gear it kicked me our of manual mode says D In the cluster in manual side goin up or down does nothing, goin back in D an trying so switch back does nothing..but when u shut the car off and restart manual mode come back.

That's a new one to me. I suppose it's some sort of overrun protection... it only started happening after the diff change, right?
Does it happen at any specific RPM? Have you tried to set the manual to any other gears, like 5 or 2 (and drive slowly)?
What if you drive normally for the same amount of time in normal drive, then try to go manual. Does it work, or basically you lose manual after 10 minutes of driving?

If there's no check engine light along with the issues, it's time to go to the dealer.


This won't help you, but I can't help but think, "Does this mean it is easier or even more difficult to do a manual conversion?"

Well I would say it's complicated a lil bit of yes and no.. bein that this is the 2nd time I've changed my diff 1st time with the m45 dif there was no issues.. this time around there was no issues at 1st about a week or so.. them it did give me a check engine light p1720 which points to a speed sensor and p1716 which is the turbine revolution sensor that I asked u about previously.. but I didn't even notice the manual override or it kickin me out of manual mode until u mentioned to me holding it in 3rd or 4th. N it stays in manual mode forever as long as I'm shiftin thru gears accordingly it does not kick me out as long a i don't max out 3rd or 4th.. so no I wont be headin to the dealer jus yet as it does not fully effect my driving ability.. it still shifts fine in D and as long as I'm shifting thru gears manual mode works find so I'll still try n figure it out on my own..I'll be leading towards changin out the turbine revolution sensor only downside to that is Its in the valve body so I'm goin to have to drop the pan.. no rush tho I'll continue investagating till I get to that point.. n no I have never really thought about a manual conversion. Maybe a lil but jus the thought of it seems like it would be too much work lol.

Would that be P0720?
The only common thing between that and P1716 is the harness or connectors... unless your transmission is about to explode. Disconnect and reconnect the harness(es) going to the transmission. Disconnect battery overnight... hopefully it straightens out.

Otherwise, stick to D and keep trucking.

No I'm 100 % sure it's it's p1720 as I'm lookin at it now I took a screen shot of my faults jus those too.. when I look up 1720 it's points to a speed sensor.. and that was 1 of my thoughts as well to check the connections but the only harness I can really see in the transmission area is from the crank sensor under there.. if u get a chance double check on your 03 m45 n Tell me wat If any harness u can find goin to the transmission.. that would be gladly appreciated.. pics if u find any would be cool as well. Thank you in advance

No pics from my 03, but it's generally somewhere round here

EdBwoy wrote: ↑

Thu Apr 20, 2017 8:48 pm

....


...

I might have to dig deeper in the FSM to find P1720. I couldn't immediately see it in the EC or AT section of various years/models.

Yea thanks I found them I was lookin on the wrong side there all in the passenger side.. everything is all disconnected now, im gon let it sit till the morning n she how it goes.. n yea I also was lookin thru the manual n there is no p1720 in there but that is wat my torq pro app is reading but when I do read the details it does say the same thing as p0720 so maybe the app got the codes a lil mixed up a bit lol.. I'll keep u posted on how it goes once I reconnect everything

Could you take some pictures of the plugs and stuff when you go back under there? That'll be much appreciated

ok cool i can definitely do that I'll email them to u.. I'll probably go back under there in a few n try n clean all the connections there 3 of them..

Can you keep us updated on what's going on? I was just about to do this rear end swap. I'm looking for info about the G37 (posi) rear end. It's mod or nothing for me too.

Put everything back together.. the car shifts fine but it's still throwing the same codes and it disables manual mode if I floor it either in D or M.. I'm goin to change out the turbine revolution sensor when I get a chance. I'm jus gon roll with it for now. I really am almost certain it's not diff related as this is my 2nd diff swap.. M45 dff had no issues for about a year.. i think it's jus a coincidence.. it still pulls harder then ever when I step on it.. that being said the g37 diff is the route I wanted to go but it was a lil bit more pricy, it will fit ur just going to have to swap out the part that connects to the drive shaft with the one off your original diff.. let me kno how it goes if u do go that route.

Yeah, it sounds like it's still driveable to me.

I don't think this matters, but out of curiosity, are the ABS rings on the diff axle stubs in good shape? If they had an issue, then I'm guessing they would throw the ABS, SLIP lights, show a speedo issue or something else through the ABS module... but I thought I'd ask.

And would you know if the size and number of teeth on the pickup ring is the same across the 3 diffs you've had?

I want the G37 diff... Badly!

Yea abs rings seems to be in good shape.. and I'm not sure about the size and number of teeth at 1st glance they seem to all be the same size but I'll double check n count the number of teeth on all 3 of them to be certain

Hey everyone,

A G37 sedan just hit the junkyard, and I can go down and grab that diff. It's raining today, so hopefully I can go and get it tomorrow. I've seen a lot of misinformation on the web while looking for specs and how to spot the right diff to grab.

For example, G35 with leather seats will have an LSD. If it doesn't have cruise control, it will have an open diff, etc, etc.

How can I tell, for sure, that the G37 I'm going to get the diff off of, has an LSD with a 3.69 gear ratio?

All the best,
~HollywoodJackson~

On options, the one thing I knew for (almost) sure on the G35 sedan was that if they got a manual trans they were LSD. Coupes, maybe all manuals had LSD plus some autos.
I think way more G37 had LSD, maybe even all coupes regardless of trans. Take all that with a grain of salt though.

One way I have done is to check the FSM rear final drive section, or was it maintenance section? I believe that's where it tells you what the cars came with from the factory, unless someone made a change.

And if you have access to the VINs, I believe you can also run them online and get options.

Thanks EdBwoy!

I wound up getting an LSD from a 2005 350Z. It works great! IO also have the P1720 [v/sp sen (a/t out) EC-561] code with the Check Engine Lamp.

There probably isn't any way to fix this, is it?

All the best,
~HollywoodJackson[/b[]~

So, I notice this conversation has sort of died out. I really want to know what other mods DarkKnightQ has done. I still want to add around 5-7 pounds of boost eventually. My next mod though will probably be the G37S Akebono brakes and sportier wheels.

So far, I've put BC Racing coilovers and the '05 350Z vlsd. I thought the coilovers were going to be the most bang as far as mods. WRONG. The 350Z diff is OFF. THE. HOOK. Both rear wheels lock up nicely. The acceleration is crazy! I need to unplug all of the sensors at the wheels, and the two sensors on the diff. Then I think I will be able to burn the wheels and get the car sidewayz, as in really drifitng.

Since I lowered the car, I've developed an exhaust leak right before the Center Muffler. This actually has the car sounding great!. Another code I get now is that the intake is getting too much air. I guess this is because the exhaust is flowing a lot freer.

Regarding the code you all say you couldn't find above, I found it in the EC chapter of the FSM. P1716 refers to TURBINE REV S/CIRC and can be found in AT-123.

All the best,
~HollywoodJackson~

350 z diff sounds like fun lol.. how was the install? Even swap?

DarkKnightQ wrote: ↑

Mon May 14, 2018 12:34 pm

350 z diff sounds like fun lol.. how was the install? Even swap?

Even swap, perfect fitment. The only thing I HAD to do to the 350Z diff was to remove the driveshaft flange, and replace it with the one off the Q45 diff. I did open it to check the inside off the diff and apply a new gasket and fluid before installing.

It. Is. Fun! I think the gearing ratio may be slightly different from the FX35, however. It could be the same, I'm not sure.

As far as the trouble codes (I'm getting some weird trouble code behavior as well, with the diff swap). I have P1720, and P1140 and P1145. The speed sensor, and the other two for bank 2 Var Valve Timing sensor and VVT Control code. What is interesting, is that before this, I had P1720 and the trouble code for Bank 1 Cam Position Sensor. What I did after getting the bank 1 code was, I swapped the Cam Position Sensors to see what codes would pop up. If the Cam Sensor Bank 2 code appeared, then surely it would be a faulty Cam sensor. Well... That's not exactly what happened. After swapping sides, I didn't get a Cam Sensor bank 2 code... I got P1720 and bank 2 codes for the VVT sensor and VVT control.

Looking in the FSM, I see the VVT control, VVT sensor, and Cam sensor is listed to be in relation to the Speed sensor. The ECU takes all of this data into consideration to adjust VVT. Easy enough to understand. Honestly I think the Cam sensor MAY be bad. But the cause of the problem is the ECU not understanding the different readings its getting from the two speed sensors (1 signal from the tranny, the other signal from the sensors at the diff and the wheels not matching)...

All the best,
~HollywoodJackson~