The Nissan Path

Hello Everyone,

I own R51 Pathfinder 2.5dci, manual 6 speed (2006). I know that there aren't many diesels on this forum but this question is only powertrain related.

What happens is, when I shift to 1st gear, start moving, press clutch, shift to 2nd gear and on clutch releasing, on the moment when flywheel and clutch connect, when power gets transmitted from engine to powertrain, I get to hear 1 CLUNK - just one. Same thing can happen between 2nd and 3rd gear, probably between 3rd and 4th and so on but then I can't hear it because I move to fast. It doesn't happen every time, looks like it depends in which position something is.

- I know it shouldn't be the transmission because it was in service 3 months ago and got the new clutch set and flywheel.
- I know it shouldn't be the transfer case because it got the new seal on the front side in service and oil was checked then.

I wanted to check by myself what's happening bellow so I'v recorded one small videos for you guys, just to help me identify which sounds are normal, and which are not:
1) Sound in the front diff when moving driveshaft.
2) Sound at the beginning of that right "rod" getting out of the front diff.
3) Sound of the left "rod".
Video can be seen on this link: https://youtu.be/UfWQwSF40sE


Thanks.

According your description of "clunks" appearing I would check the drive shaft joints. (both ends of front and rear drive shafts).

I think those clunk sounds will appear also when you are accelerating and releasing the gas pedal, no gear changes needed.

I'd say for:
1.) There's way too much play when moving driveshaft. Seems like pinon is too far away from gear, which is controlled by collapsible (non-reusable) spacer. Repair needs skilled drivetrain mechanic, specialized for Nissan, because he will need proper spacers (there are more than 20 of them in different dimensions) and collapsible spacer, all properly adjusted to specs.
I've been with one of them rebuilding diff some time ago and it's pain in the ass to set it up all properly. After few hours he put everything together, measurements were not correct (normaly), then put everything apart, change spacers, repeat. Not good, again apart, again tigether, measure....and so on until gear is ok. Then pinon...again same story, except for the detail, that you should not overtight collapsible spacer, as you cannot stretch it back - you need to take new one.
In short - time consuming and precise work.

2.) Regarding half-axles, the axial play (in-and-out) is by my opinion not so problematic, as is possible vertical play (up-and-down), as long as there's no oil leaks.
Replace oil (I use 75W90 Full Synthetic for both diffs) and inspect plug magnets and what comes out for possible metal particles. Especially be alert when pouring old oil out if at the end you will get some smudge, milky oil. That would mean your diff soaked water in, so repeat oil change process after few hundred (or thousand) miles again.

2b.) Check the stamped mark on the diff (cross-hatched area):

The stamping goes from left to right, after every diff service:
- For every oil ring replacement, there's "0" stamped at far right
- For every oil ring + collapsible spacer replacement, there's "1" stamped on far right
- IF nothing of above has been changed, there's no stamped mark at all.
So you will know, what has been changed at all and what lately.

3.) Metallic sound of left half drive axle....hmmm, is it coming from spline area where shaft meets diff? Or it comes from CV joint on half-axle itself?
- if coming from inside diff, it could mean side-ger has too much play, again same procedure as for (1)
- but if it is coming from CV-like joint on axle itself, it might mean your rubber boots are leaking, grease is gone and joint is zombie. Replacing half-shafts is not so expensive.

Taavi wrote:According your description of "clunks" appearing I would check the drive shaft joints. (both ends of front and rear drive shafts).

I think those clunk sounds will appear also when you are accelerating and releasing the gas pedal, no gear changes needed.

Hi Taavi, I'v tested accelerating and releasing the gas pedal, which should show up that free-play on U-joints but that's not happening. I'm gonna try to do another video for you guys where you can hear exactly what I'm talking about. I'am almost always able to replicate that when reversing, put into reverse, release clutch fast (not gently as I would normally do), and on that fast connection, I almost always hear that "muted", "low-frequency" clunk.

labsy wrote:1.) There's way too much play when moving driveshaft. Seems like pinon is too far away from gear, which is controlled by collapsible (non-reusable) spacer. Repair needs skilled drivetrain mechanic, specialized for Nissan, because he will need proper spacers (there are more than 20 of them in different dimensions) and collapsible spacer, all properly adjusted to specs.

Hi labsy, thanks for your detailed reply. When talking about the pinion, you are talking about this "driving pinion" right? Being too far from the Crown Wheel (just trying to learn things while here)? http://web.mit.edu/2.972/www/reports/di ... tial-1.gif
My very good friend works at official Nissan Service in Serbia and I'm sure that they have proper tools, but they are usually too busy changing oils on Xtrail and Qashqai to research and experiment so I'm trying to get there with clear ideas. And I always have time for my Pathfinder.

labsy wrote:2.) Regarding half-axles, the axial play (in-and-out) is by my opinion not so problematic, as is possible vertical play (up-and-down), as long as there's no oil leaks.
Replace oil (I use 75W90 Full Synthetic for both diffs) and inspect plug magnets and what comes out for possible metal particles. Especially be alert when pouring old oil out if at the end you will get some smudge, milky oil. That would mean your diff soaked water in, so repeat oil change process after few hundred (or thousand) miles again.

Is there any thread about diff OIL changing, can I do it without Service? I'm assuming that pouring old oil out is not a problem, but pouring new one in without that little pump they use in the service - is it possible?

labsy wrote:2b.) Check the stamped mark on the diff (cross-hatched area)

I will definitively do this, thanks for the clue. Unfortunately, knowing what everything I serviced on this Pathfinder and previous owner didn't, I doubt that someone ever changed oil in the differentials. Also, can this sound occur if there's not enough oil or oil is worn?

labsy wrote:2b.) Check the stamped mark on the diff (cross-hatched area)

It's definitively coming from the CV-like joint on the axle - on the wheel side, not on the diff side. Also I can see some oil there.

First off, Jovan, greetings to Serbia (from Slovenia)

One other thing crossed my mind when you say you can replicate that chunking sound in reverse more often, than in forward gear. Take a look at possible engine and diff holders. It was very common with some older cars for engine to "clunk" up/down a bit when starting, because of worn out rubber engine mounts.
Also check dampers mounts and any other possible mounting points, where there is rubber inbetween.
Rubber worns out and metal parts of engine (or diff, or maybe also dampers) mounts clunk together, producing one-time metal "clunk" sound, and NOT repeating thereafter.

Regarding changing diff oil it's quite simple, with few details in mind:
- when undoing fillling and drain plugs on diff, first undo FILL plug, only then drain plug. Why? If you cannot undo filling plug and you already drained oil out, you are toast
- the filling hole is quite high, so if you don't have pump, you can go MCGiver way, like me. I took one oil bottle, made a hole in the cap and put rubber hose in. Then I taped it with duct tape tightly, so I can screw thi modified cap on every new bottle and squeeze it with my hands and fill the oil into diff.
It's as small amount as 2 liters, but your hands will feel pain if you are computer tech like me

Just throwing this out there, but these vehicles did have issues with "clunking" in the front end due to the front sway bar mount bushings allowing the sway bar to "clunk" against the crossmember. There was a service bulletin released instructing to install countermeasure sway bar mount bushings, which put the split in them in a different position rather than directly between the bar and the crossmember. I would hate to see you spend a whole lot of time and money on the front diff and have it turn out to be a couple of mount bushings that sell for less than $10 from Nissan. There have also been a few reports of bad body mount bushings, as well.

Did you find out what the problem/solution is? I have what appears to be the same issue. I have less free rotation in the driveshaft, but also get the single clunk at initial acceleration from a stop.

Thanks