New owner/member

[armybrat]

Hello all, just purchased my first Infiniti, a used model 2012 M56x with tech package and 52,000 miles. This model was really hard to find, at least around North Carolina...had this one shipped from Tennessee. I would like to verify the newest navigation program and map version if possible. The info on the screen reads:

Map Version: GEND NA G.A
program Version: X3U42006

Car runs great, only issue I am experiencing is slight vibration/shaking when traveling on the interstate. I can feel it in the steering wheel and the seats/console. Tires are new and balanced, and alignment is good. Only other things might be suspension related, or driveshaft out of balance...also heard that this is normal for this model, and was wondering if anyone else has this issue.

Thanks for any info!

[adeedpb]

Welcome to the forum and congratulations on your purchase! I am not sure if the vibration is an issue for everyone. I have noticed very slight vibrations around 65 but it smooths out before and after that speed.

What speed is the vibration most apparent?

[SwissCheeseHead]

Welcome! I have 40K miles on my M37x and feel no vibrations. You will want to check control arms, bushings, ball joints, etc in the suspension. Make sure your wheels are torqued to 90-95 ft/lbs. Let us know what you find out.

[ibc]

My M56x has only 22K miles, but smooth as silk. No vibration, at all. Not yet, anyway.

Check wheel balance on vehicle (vs. off)? maybe you lost a counter-weight? Are your driveshaft U-joints worn out and loose? Drive-shaft (aka. propellor-shaft) U-joints must be aligned and in-phase with each other. In other vehicles, it's common to un-align them by accident when reinstalling them in a slightly different orientation (ie, forgot to mark original position). A bent driveshaft (ie, runout) is much less common, but you can sometimes use a hose-clamp to DIY fix it.

Also the center bearing between the front & rear propellor shafts might be worn, which causes vibration. On my 4x4 truck, mine was badly worn, so I replaced the 2-piece driveshaft with a double-length 1-piece driveshaft that no longer uses a center bearing, which fixed the vibration for good. It's a common fix for Fords, but I doubt that it would work on an M56x.

Infiniti service manual page DLN-94 says:
After assembly, perform a driving test to check propeller shaft vibration. If vibration occurred, separate propeller shaft from final drive. Reinstall companion flange after rotating it by 90, 180, 270 degrees. Then perform driving test and check propeller shaft vibration again at each point.

[Ilya]

Welcome to the forum!

[armybrat]

Thanks all for the responses!

I found a 2016 map and software update disc set that looks like the one that is on the Infiniti website. It was in a package of stuff that came with the car. From what I gather, it has already been installed.

Regarding the vibration issue, It does it at highway speeds, 60+ mph. I took the car to a local Infiniti dealership here in Winston-Salem. They balanced the tires but it is still doing the same thing. They also stated that the exhaust system looked like it was moved/shoved forward and may be resonating against the frame and could be causing vibration. They recommended replacing the exhaust system from the cats back. I was not satisfied with this recommendation. I looked up underneath the car when I got home, and the exhaust system looks fine to me. The tips are centered correctly, the hanger brackets are straight and the piping is aligned correctly, at least from what I can see. There is no indication that the exhaust system is compromised in any way.

I have an appointment with Modern Infiniti of Greensboro tomorrow morning. Unlike the first dealership, they have a high end electronic spin balancer that supposedly checks radial and lateral runout as well as static and dynamic balance. Maybe this will help solve the issue. I will also get them to check the exhaust system more thoroughly, as well as any other items that could be the cause.

Other than the vibration issue, I'm having a blast driving this car! Thanks again for the responses. I will update late.

[armybrat]

Just an update...turns out that one tire had excess road force (40 lbs.) Also, the previous owner had the cheapest tires installed before turning the car in (lease). Goodride SA07. 2 out of 5 stars on ride quality and road noise. They got the vibration down to a bare minimum but it's just not going to ride as good with these tires. Everything else is ok.