2012 st d40auto vibration in driveline on downshift.

[Wadesymes]

Hi everyone!

First time poster long time reader of many threads.

Had an ongoing problem with me yd25 2012 d40 st auto since i bought it nearly a year ago with 85000 on the clock.

Im getting a vibration/ shudder coming from the driveline when the auto trans seems to be shifting down through gears, mostly slowing for traffic lights.. she also seems to get a slight vibration when coasting around a bend or going up an incline.

Also when driving up through the adelaide hills it climbs up through gears untill it gets to 4th or 5th then has a massive decrease in power then starts to vibrate quite a bit. When you feel the trans drop back a gear the vibration disappears and revs go back up. Nissan told me this is normal and to " just put it over into tiptronic and shift back gears myself.. this still doesnt fis the vibrations experiences when slowing at light's

Since ive had the car ive
- replaces both uni joints in rear tailshaft
- changed oils in diff and transfer case
- nissan also performed trans flush about 2 months ago

Took it to a trans specialist this morning and he cant seem to figure it out without having the car for a few days... said it could be the torque converter clutch or transmission, engine mounts as it doesnt occur all the time

Any suggestions would be great as its starting to do my head in!
About to start towing a caravan too so wanted it fixed before my first voyage with the van!

 

[Old.Tony]

Welcome!

The front drive shaft is also turned over by the motion of the wheels but it's not engaged in the transfer case until a 4WD mode has been selected. A bad uni on the front shaft (or a damaged bearing in the transfer case/front diff) could cause some vibration but it shouldn't be hugely noticeable unless you're in 4WD.

Transfer case output shaft bearings can also cause a vibration, because it leaves the drive shafts to slop around. There shouldn't be any lateral movement in the front or rear shafts - it's easy enough to slide under and check this.

Vibration could also come from a wheel bearing, but if you've been driving it for a year, a dodgy wheel bearing would have destroyed itself by now and you'd probably have seen the ABS light come on too, as it often does because when the bearing disintegrates, it drops chunks in the ABS sensor ring. If you HAVE been seeing the ABS light - there's your answer. Easy to find out which side it is - the car will make more noise in one direction or the other. If it gets noisier in a right hand bend, it's your left-hand bearing and vice versa.

The torque converters have rarely had a problem beyond the 2009 model and those were caused by faulty torque converter clutches. I don't recall an issue with TCCs in later models but there's always a first, I guess - what happened was the TCC would attempt to engage and lock the converter, be unsuccessful, disengage, then try to engage again. It happened rapidly, and would smooth out again at 90-95km/h. The trick to spotting this was to try driving the car at similar speeds but with conditions such that the TCC would NOT engage - for example, in the 2009 and earlier models, the TCC would only engage in top gear. We'd just disengage overdrive and if the vibration disappeared it nearly 100% chance of being a faulty TCC and the TC was replaced (the TCC is a component on the TC).

That might be the case on yours, but I don't know the program for the 2012 model so don't know the conditions (rules) for engagement of the TCC. Someone else might - and then you could drive in a manner that prevents engagement, and if there's no vibration you could probably bet it's the TCC.

 

[Wadesymes]

Thanks old tony

Ill jump under tomorrow and have a look at both shafts, i was told the front shaft only spun when 4x4 was engaged so might need to look closer there.

The vibration mostly occurs once its up in higher gear, driving around bumper to bumper it doesnt happen. It feels like it cant decide weather it wants to be in 4th or 5th, vibrates in 5th then jumps back to 4th and vibration stops. The gear stick on the 2012 doesnt have the overdrive button on it thats why the dealer told me to move it over into the manual mode option when going up steep hills. Having said that he also told me it was a 7 speed the whole time and not a 5 speed!

 

[Old.Tony]

It should be the RE7R01B box (same as you'll find in the 370Z) 7-speed box. You'll also find that you don't have lockable front hubs, to engage 4WD you just flick the dial and a servo turns a shaft in the back of the transfer case to firstly engage the pawls inside the chain drive connecting the front drive shaft, and further to change gear from a 1:1 drive to a 2.6:1 drive (4LO) - a total movement of 270 degrees.

It might still be happening at slower speeds, but not noticeable. Is it more noticeable in cornering one way compared to the other?

 

[Wadesymes]

I was under the impression that it was a 7 at since i bought it. When you.put it in the manual shift mode when on the highway it doesnt go above 5. So i called nissan and after speaking with 3 people who said it has a 7at, the parts dept checked with the workshop guys and decided they all have 5a, they said only the v6 has a 7at

The vibration def is more noticeable when going around big sweeping corners and when under heavy load which made the trans guy think it was the mounts.

Sometimes it feels like it can clunk in the drivers footwell also. If i feel the clunk around 65- 70 kmh it vibrates down through the gears... not a constant vibration but for the few seconds around the shift down.. maybe one or two seconds per vibraton.. sometimes stretches to a 4 or 5 sec shudder.

 

[ericcs]

sounds just like mine, which is confirmed by Tony. i have posted about this shudder before as well as others. in top gear at around 90/100kph when it starts to load up it shudders until it either kicks back or the load decreases. I have lived with mine now for 150k, so I either make it kick back or back off the throttle a bit. an aftermarket T/C and valve body replacement is what is needed if you can't live with it.

and as mentioned, only the V6 gets the 7sp box, or the new NP300!

 

[Wadesymes]

So today on the way to work it was quite frequent. Once over 60 - 65 kmh then slowing at lights etc shudder for a second or two befor each down shift.

On the way home i drove it the entire time in sport shift mode or what ever its called using only up to 4th and NO shudders the whole way home! Drove the nicest it has exept for having to shift up gears manually. It even drops down through the gears on its own when in sport mode and didnt vibrate.. back in the car later driving in D and the shudders return.

 

[Old.Tony]

Ok I overlooked the YD25 part - I just thought "V6", so yes with the YD25 you should have the 5 speed box. Hopefully you'll be missing the low range auto-shifting-in-manual error that comes free of charge with the 7-speed box.

It's probably worth checking the prop shaft anyway, and try loading it up in a corner and see if there's an audible difference left-to-right. It will at least rule out a few possibilities.

 

[Wadesymes]

Jumped under the car this arvo and had a look at the front prop shaft... uni joint at the transfercase end definately has play in it so much that it feels like it could be the bearing in the transfer case too!

Ill be booking it in for new unis and the bearing if its gone, fingers crossed its that rather than the TC

 

[Stelianos]

what do you mean play in the proshaft, if the car was parked and went under it and tried to rotate the proshaft it will always have some slack and rotate like 5 degrees (between diff and transfer case, not on UNI joints)

 

[Wadesymes]

what do you mean play in the proshaft, if the car was parked and went under it and tried to rotate the proshaft it will always have some slack and rotate like 5 degrees (between diff and transfer case, not on UNI joints)

Nah not rotation it wiggles up and down enough to make noise. The end into the front diff feels good just the one into the transfer case.

Ill get it checked regardless so hopefully it fixes it

 

[Wadesymes]

So the nav has been at the transmission specialist today. Last time i took it there we couldnt get it to do the vibration much on the test drive but this time he says its definately not right. He had another navara there today a year newer than mine and he says my nav is not comfortable at all to drive compared to the other one.

He checked the transfercase front propshaft and said it felt and looked exactly the same as the other one he had in today.
He said he checked all fluids, loosened all the trans mounts and made sure everything was aligned properly and tightened, hooked up the computer and no codes but did a reset anyway and still cant figure it out!

He wasnt too happy that he couldnt figure it out either!
After i spoketo him i called back and asked to humour me and take the front prop shaft out and test drive it but i havnt heard back yet...

Fingers crossed but havnt had much luck with it yet!

 

[Wadesymes]

So 3 days and 900 bucks later im still not convinced that its 100%. The transmission guys ended up putting an addditve in the trans to help the shudder to no avail. Then changed the trans mount which was quite compressed and worn but the guys think there is still a resonating sound coming from the engine maybe now??? They suggest to maybe get the ecu remapped and that might make it run better??

I also thought a de carb clean might help things run better unless its an internal problem in the engine also. Hope not as i would like to try fix it rather than last resort of selling it for something else!


So after driving it today, still getting a slight rumble around 55 -60 km but not all the time. The heavy shudder is gone so that must have been the mount. Still feels like something is trying to get it to vibrste like it did but the new mount is stopping it. Which is a positive but would still like to get rid of it all... the engine also seems to make quite a low note and get a bit sluggish up in high gear low revs. Hope its not timing chain or something like that. Stuffed if i know!

 

[Old.Tony]

A D40 being a slug below when the turbo can boost properly is no big surprise, really. Around 1100-1200rpm mine performs something like an old Volkswagen.

 

[Wadesymes]

So the shudder on the downshift came back about a week after the mount was changed. So i took it to another transmission place who took live data from the tourqe converter.

Looks like its the torque converter having a disengage issue. After driving it with him and learning more about when its on and when its off and how the brake switch turns it off i can now drive it differently to make it do it less. Still does it sometimes even with the brakes on but way way less.

Another strange thing is that i put a egr blanking plate in 4 days ago and since then the throaty sound with the sluggishness in high gears has gone! Hasnt fixed the tourqe converter but it drives completely different with not funny note under load and much more responsive.

 

[happy john]

Unusual for you to notice any difference in higher gears at speed, the EGR is only active at lower rpm ect.

 

[Old.Tony]

I'd venture a guess that the EGR valve has a minor fault causing it to open too much, introducing too much exhaust gas to the intake at low RPM. John is right - EGR is inactive at idle and full throttle (zero and full throttle, which is not always going to be idle and high rpm!), it's only there during mid-range throttle operation (which is where we spend most of our time). At higher RPM the valve may be open more and the engine notices it less, so the effect of a faulty EGR valve will be less noticeable at higher RPM.

You'd need to confirm this, but if yours is the 4-banger, the torque converter should only lock up in top gear. If that's the case, simply flicking the overdrive button (so that overdrive is now OFF) should prevent the transmission control module (TCM) from even attempting to engage the Torque Converter Clutch (TCC). If the driveline has settled with no TCC engagement then it's pretty obviously going to be the TCC at fault.

Certainly in older models (pre 2010) the TCC had faults which caused vibration around 80-95km/h which is the normal TCC engagement speed for those cars. Nissan were replacing the TCs under warranty because the TC had an actual manufacturing fault which prevented the smooth engagement of the TCC. There have been no reports of 2010 and later D40s with faulty TCCs. Since your box is showing a fault on the other side - the disengagement side - I'm thinking it's less likely a logic/sensor fault and more likely the TCC solenoid.

I've never heard of someone pulling the TCC solenoid out. It may be an electrical issue (dirty connections will reduce the current-carrying capability of the connection) but the only way to determine that is to drop the box out.

 

[msilv]

vibration dramas

I've been reading your post and i have exactly the same problem with my 2010. I've replaced trans mount too and that was a waste of money, flush trans, and check uni joints too.
From what ive worked out a custom remap of ecu can help with vibration when slowly accelerating. It will give you more power and quickly get you out of the bog that you feel like your in but at roughly $1500 it aint cheap.
With the problem of it clunking as you slow down into low gear a remap would unlikely fix that. i was thinking bringing it to a differential specialist and getting the gears re meshed for excessive slop.
My ute has been doing it since 50,000 km and i believe the vibration is a problem direct from nissan design in their automatic boxes. Overdrive sits at 1600 rpm and our little engines dont have enough torque to get us quickly into boost range. i believe nissan have designed 7 speed auto to counter react this plus the help of twin turbo to their latest model.
My suggestions may or may not fix our issues but i believe they would definetly help but for $1500 on each fix its not cheap.