Posted: Sep 24 2008 at 6:10am | IP Logged

 Does anyone have any ideas! I own a Nissan Navara D22, I was driving along in 5th gear at about 70MPH when there was a loud thud underneath the vehicle (sounded like I had run over something that had come up and hit the bottom the vehicle). The vehicle developed a judder.

The Judder is only realy noticeable when travelling in either 4th or 5th gear and when the vehicle is under load (i.e accelerating, most noticable between 30 and 60 MPH). The vibration also gets louder and more noticeable when the vehicle is going over a bump or dip in the road.

I am no mechanic, but I did the usual took all wheels off, checked for anything obvious like a brake seized, Tyre tread seperating, bearing gone, play in the drive shafts front and rear, but nothing obvious is showing...

There is only one thing that looks strange, where the front drive shaft meets the rear (assume the main bearing) there is a steel rod/strap that connects the bearing housing to the underbody of the vehicle.. It looks like a stabiliser strap or something. However in my case this strap looks like it should have been mounted into a rubber bushing or bung / bearing of somesort.. (I dont know what it was like before because I never looked underneath), however if the said support rod was mounted centrally in such a bushing then it would have the effect of pulling the whole drive shaft connection over by about 5 to 10mm towards car centre!

Has anyone any knowledge of this strap or its purpose? Am i on the right track? I would be most grateful if anyone can help because the Nissan dealer simply tells me I need a whole new driveshaft bearing assembly circa 200 Pounds!!! (replacement part comes as an assembly as per normal!!) Basically I dont want to spend out this type of money not knowing if it is the root cause!

Please anyone with experience of such a problem or how to fix it get in touch..

Helpful suggestions only.. Thanks.

Posted: Sep 24 2008 at 9:03am | IP Logged

The dealership would have it correct, that is a driveshaft bearing.  It helps supports the drive shaft to keep the correct angles needed, and keep from having one long driveshaft from hanging down that can get caught on things. 

I would get this replaced ASAP because leaving it broken like that can do some serious damage to your truck bed, u-joints, and drive shaft.

Posted: Sep 30 2008 at 6:01am | IP Logged

kcidmil & frontierguy thanks for the responses

I spoke with another dealer, they advised that i try taking out take out the last section of the propshaft (effectively putting the vehicle into permanent 2 WD) and take it for a test run, to determine if the fault is indeed the main propshaft bearing or not.

This kind of makes sense to help isolate the issue.

Whilst I understand what you have both said about the main bearing. The bearing outer looks pretty much intact and there is very little play in either the front or rear section of the prop. (1/2 inch rotation in the rear end after the main support bracket and 1/4 inch play in the front section from the gearbox to the main bearing) So I can't see it as a bearing issue.

The Vehicle is a 2004 D22 Navara, and until this I have had little problem with it..

The garage advised that the strap which i think is linked to the problem is only to protect the floorpan in the case of the main bearing failure... this means if the front propshaft section seperates and drops the bracket will prevent it from coming through the floor and causing injury to the occupants of the vehicle.. (I personally don't think this is the true function of the strap).

To me this strap puts a slight tension into the main bearing assembly and would be enough to dampen a vibration such as the one I am having...

The garage engineers also contradicted themselves when asked what was going on because 2 guys said there is no rubber bung present, then a third engineer came through into the office and said oh has the rubber bung fallen out!

I am not trying to catch anyone out here, but it seems like there is a fault that could be known about by dealers and the fix is quite simple, yet all the dealer wants me to do is drop the vehicle in with them to be fixed! Tell me he is going to install a complete new bearing housing and simply re-fit a rubber bung and mounting strap... Something doesn't seem right here...

Does anyone else agree?

If it was a bearing issue then the vibration should be present through all gears right? and not just at certain speeds? I would feel excessive freedom of rotation in the shafts themselves! but I dont... The car is still driving fine but the vibration is still there, no worse than when it first started... Its gotta be something really simple I am sure of it... Other ideas anyone?