Drivetrain Vibration

[abw]

A number of guys with gen 4 (petrol auto?) Pajero's have had problems with vibration in the drivetrain, typically between 2100-2500 RPM. Soon after buying my NS, I noticed this.

I had a search through this forum and typical fix involved removing the vibration damper hanging off the rear diff. So I removed mine, which made a big improvement..maybe 50% change. But it still bugged me, so I had a look at what the guys with gen 3's were experiencing/doing, as they have an almost identical drivetrain. Buried in one thread which I can't find again, there was one guy who changed his transmission cross member bushes. Anyway, I decided to do the same!

After replacing the bushes, I reinstalled the vibration damper. I'd say this almost got rid of the vibration. If I'd hopped in and driven it for the first time, I don't think I'd notice it now.

This is the vibration damper. After I installed the cross member bushes, I re-installed this.


And this the location of the bushes in question.


There are 4 upper (Mitsubishi P/N MI-2910A066) and 4 lower bushes (Mitsubishi P/N MI-2910A065). There are 2 of each type either side of the cross member. Simply use a 14mm socket to remove bolt one at a time. You will remove the bolt, lower rubber bush, which has a steel spacer inserted in it. And you simply slide out the upper rubber bush (sits between the cross member and car body). Remember to replace these assemblies (along with the steel spacer) one at a time.

By the way, the bushes only cost around $7 each from my local Mitsubishi dealership...they cost $15 off Amazon!

Hope this helps people.

[sub888]

Thanks!!
I too have started getting a vibration and it seems worst around 80kmh. It is not bad in fact most people would not even notice it. It just annoying knowing it is there. Wonder if this is my problem.

[abw]

Thanks!!
I too have started getting a vibration and it seems worst around 80kmh. It is not bad in fact most people would not even notice it. It just annoying knowing it is there. Wonder if this is my problem.

Yeah, the vibration typically shows itself in the 2100 to 2500rpm range, more noticeable under load (up a hill, loaded up, heavy acceleration).

If vibration is just speed related (not RPM related), then the first thing I'd look at would be wheel balance.

[Brissyguy]

The main reason is that the rear gearbox mounts also acts as the rear engine mount. Lots of torque load and heat near the bushes. So as soon as it gets any wear or hardening bushes it gets worse real quick

I'm about to change mine and one thing that really makes it bad is if you have the transmission after market guards fitted, due to the way they mount it transmits direct vibration to right under your feet in floor pan which makes you notice it more too.

Grab the rear of the gear box and give it a shake it scares you how much it moves round lol. And it just sitting on the small blocks of rubber on the rear mount, so you can imagine how much it transmit noise once they start to age.

I'm only changing the bushes on the mounts too as to do the mount MMA want $400 lol and the eBay cheapie just don't look that ideal with the rubber.

I'm looking at front engine mounts too. In my HSV I had to do three sets over about 200,000k so if I have to do one set at 185,000 in the paj that not bad

I'm sure everyone who has the vibration even. Notices it more once they aware of it and it drive everyone mad lol

[abw]

.......
I'm only changing the bushes on the mounts too as to do the mount MMA want $400 lol and the eBay cheapie just don't look that ideal with the rubber.

I'm looking at front engine mounts too. In my HSV I had to do three sets over about 200,000k so if I have to do one set at 185,000 in the paj that not bad

I'm sure everyone who has the vibration even. Notices it more once they aware of it and it drive everyone mad lol

Yeah, there is still vibration there, especially if I have 150kg of camping gear and the family on board. But not too bad now.

That $400, was that for the centre bush assembly?

Anyway, I'm over it now. Wanting to do fun stuff with Paj...like lift, bullbar etc

[Brissyguy]

Yeah, there is still vibration there, especially if I have 150kg of camping gear and the family on board. But not too bad now.

That $400, was that for the centre bush assembly?

Anyway, I'm over it now. Wanting to do fun stuff with Paj...like lift, bullbar etc

I found out today when I ordered my little rubber bushes, they screwed up on the $400, lol
It was for the whole cross member/mount that is support by the $9 rubbers. Not the rubber section that on top of it lol

[abw]

No worries. I was too lazy to replace that centre bush assembly..just went for the easy to get at ones

Interesting what you were saying before about the aftermarket bash plate vibrating or adding to driveline vibration. I've got some 5mm thick strips of rubber I'll put between the guard and cross member. See how that goes.

[Brissyguy]

No worries. I was too lazy to replace that centre bush assembly..just went for the easy to get at ones

Interesting what you were saying before about the aftermarket bash plate vibrating or adding to driveline vibration. I've got some 5mm thick strips of rubber I'll put between the guard and cross member. See how that goes.

That what I was thinking off or something like it next time I pull them off to clean out

Let me know how yours go. Cheers

[Benji]

Hi,

I notice a vibration but only when in 4H and only at around 2000-2200 and goes away outside of that, do you think this would be bushes also? Car is NT Auto with 80k.

Ben

[Cam1971]

Hi folks,

ABW is absolutely spot on with the analysis, (and some of the other threads I have read) that the particular rev related vibration seems to be related to aging crossmember bushes. I suspect when MMAL had vibration issues was when the bushes are new, therefore the damper they added seemed to fix a particular observed vibration. As the bushes loosen on the crossmember due to damage or getting hard, it must change some dynamics, and the damper actually worsens or creates a new harmonic vibration (which in many people have including me, have it occurring around 2000rpm).

I have a Gen 4-1 2006 NS v6 Auto, 105k, and had the same harmonic vibration at around 2000-2300rpm (and on another NS I test drove and was worried at the time) in any gear, including neutral. I tried a suggestion (from another thread) this morning, to try placing a jack (in my case a cheap hydraulic trolley jack) gently pushing up on the center of the crossmember, and with the handbrake firmly on (and a wheel chock) start the engine and see if the vibration disappears (in Neutral). In my case it did disappear completely!!

I am going to try to remove the dynamic damper (which my pajero has still) and observe the results. If not satisfied, Ill replace the crossmember bushes as outlined above and put the dynamic damper back on. I will add the results to this thread soon.

BTW I just added myself to this forum, so howdy everyone
-Cam

[markc]

for me the biggest change I got was replacing all my rear gearbox mounts and removing the damper at the rear of the gear box, not the one at the diff
This was on a NM and although I removed most of the vibration (80%) it never really eliminated it.
It was always just over 2200rpm and could be detected in any gear in neutral, high or low range.
From memory I had the NM until around 265,000klm with no apparent issues or worsening of the problem.
Also over time mounts tend to get softer not harder.
For those replacing the whole cross member try Amayama for parts. It takes a few weeks to receive them but they are typically 1/2 the price of Australian MM stock and are genuine ex japan
Cheers Mark

[Cam1971]

All fixed!!!

Hi folks, Just a followup message from my first post in this thread.
Great news! I took the pajero to my local Mitsubishi service centre, and told them about the vibration issues I was having. I mentioned the hot line fix NS23-001 and they immediately applied the fix, which was to remove the rubber block damper from the back of the transfer case.
The pajero feels like a new car, all fixed in my opinion, no noticable vibration or drone noise from any rpm, in all gears.
Since I was out of warranty the charged $60, which I felt was very reasonable!!
Success!!
Cheers, Cam

[KrAsh]

Thread dig but it relevant to my interests at the moment.

I've been chasing a strange driveline vibration in the NS for a while now and it is eluding me big time. Have done the rear diff support bushes front and back, gearbox crossmember bushes (as mentioned in OP post) and still have no resolution.

The vibration has become less severe however is pretty bad and the only other thing I can think of now would be the tail shaft, however the vibration isn't consistant with rpms or loading nor does it do it on acceleration or decel, mainly at random times on very light load and actually disappears when release the throttle. I'm hesitant to lay blame on the tail shaft being out of balance as the shake isn't there all the time, you can hard accelerate cleanly through the gears no issues.

Before I seriously consider petrol and a match has anyone investigated this any further?

Cheers, Ash

[Goodsy]

Could be a drive shaft CV or more likely a drive CV or ever a wheel bearing. Have you checked the backlash in you rear diff?
What's it like in 4H?

[KrAsh]

Could be a drive shaft CV or more likely a drive CV or ever a wheel bearing. Have you checked the backlash in you rear diff?
What's it like in 4H?

Backlash is on limit just a bees under 5mm.

So having done all bushes and back together (I was missing the collar out of one of the trans x-member bolts, I've never had off before so anyone's guess) the shudder is now almost doable on command.

40kph and back off throttle it does it, I'm almost blaming the diff here without looking into what type of centre is in it. The lockup releases and bang bang bang bang, but is not doing it anymore at cruise speeds.

So now I have a slightly better rear end but still an issue, may have to suck it up and take to a driveline specialist