FAQ: CV joints, clicky axle, common problem

[Husky]

Hopefully this helps people understand what the "clicky axle" problem in the 350z is. Most of this I've not written myself but pieced together passages from various places to make something relevant to the 350z. Before I had my own clicky axles repair I had hoped to get a sound recording of it to add, if someone could do this it would be much appreciated and could be added into this post.

 

Something worth noting is that "clicky axles" shouldn't be confused with a "clunk" from the ARB drop links. These two sound different, the "clicky axles" are a higher pitched clicking like steel ball bearings or marbles rolling around hitting together while the ARB drop link "clunk" normally sounds like a shift in two mechanical components past each other transmitted through the chassis to sound like a "clunk".

 

 

 

What is a CV joint, how does it operate and how can it be fixed in the Nissan 350Z

 

 

Constant-velocity joints (aka homokinetic or CV joints) allow a rotating shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or play.

 

A CV joint consists of a six steel balls that run in grooves on a spherical ball and socket which are held in place by a cage between the ball and socket [see Fig 1,2&3]. The cage always floats in a neutral position holding the balls in the correct location. While the joint is in motion the individual balls move back and forth along the grooves.

 

Fig 1

 

Fig2

 

Fig 3

 

 

A CV joint or constant velocity is a type of mechanism that connects two fixed rotating shafts. This joint allows the shafts to be connected while axis pivots change, for example when suspension movement occurs. CV joints are widely used in front-wheel and rear wheel drive cars. CV joints can deliver torque more evenly then conventional "U" joints [see fig 4]. The CV joint is used because of its ability to transmit more even torque throughout a particular flex range. A CV joint can also deliver power on a wider range of angles then "U" joints, which makes them more desirable than its older counterpart. One difference between the two joints is the way they are serviced. A CV joint is constructed with a rubber boot that is meant to contain the lubricating grease. A typical "U" joint has grease seals on each bearing cap so a boot is not needed. The CV joint is virtually non-serviceable unless the boot ruptures or extreme conditions exist, like high mileage or abuse. When the CV joint fails simply replace it with a new unit.

 

Fig 4 ("U" joint)

 

An interesting point worth noting about all the ball type CV joints is that the balls, cages and tracks are a precision fit assembly with close tolerances. So if a joint is disassembled for cleaning and inspection, the balls should be returned to their same original positions as before. Play between the balls and cage windows can produce a popping or clicking sound when the joint is operated at an angle (as when [suspension compresses]). Insufficient clearance in the joint can cause binding and galling that can damage the balls and tracks as well as crack and/or chip the cage windows.

 

 

CV JOINT LUBRICATION

 

CV joints require a special type of high temperature, high pressure grease. Ordinary chassis grease or multipurpose grease should never be used in a CV joint.

 

The condition of the grease as well as the amount of grease in the joint will determine how long the joint lasts. One of the purposes of the boot that surrounds the CV joint is to keep dirt and moisture out. The other is to keep the grease in. If a boot is torn, cracked, punctured or comes loose, dirt and water can contaminate the grease in the joint causing accelerated wear which will eventually lead to joint failure. Loss of grease can also occur which will further shorten the life of the joint. So the boots must be in good condition to protect the joint.

 

Boots often become brittle with age and exposure to heat. Boots can also be damaged by road hazards and the careless use of j-hooks by a tow truck operator. Old boots should never be reused if a CV joint is being replaced. That is why most new CV joints come with a new boot.

 

 

A brilliant guide for fixing this common problem as a DIY has been supplied here by toffeeman.

Guide

viewtopic.php?f=35&t=15928

 

 

Ref 1: http://en.wikipedia.org/wiki/Constant-velocity_joint

Ref 2: http://www.2carpros.com/how_does_it_wor ... _joint.htm

Ref 3: http://www.aa1car.com/library/cvjoint1.htm

 

 

 

If you have any points to add please feel free.

 

Husky

 

The clicking noise on the rear axle is caused by the faces of the cv joint and the hub not marrying up correctly and a film of rust developing.

 

The grease and rotate procedure temporarily removes the click as what is done within this procedure is cleaning the rust off both faces, greasing both faces and turning the cv joint 180 degrees so that it is marrying up to the hub in a different position.

 

This is what Nissan do under warranty, which gives them a bit of time so that the car goes out of warranty. If you push you can get new drive shafts from them.

 

Nissan do not regrease the actual ball race within the cv joint as this is not the issue.

 

Any one that has actually regreased the cv ball race and found that the clicky noise has gone do not realise that the noise has actually gone because they have refitted the cv joint on a different spline hence inadvertently rotating the shaft albeit not by 180 degrees.

 

Nissan still supply the old cv joint over the counter to customers, in fact the same cv joint is fitted to the 370.

 

I supply an upgraded cv joint which amongst other things has a different angle on the face of the cv joint which marrys perfectly with the hub.

 

I think people are getting confused with the older type cars, especially FWD vehicles where clicky cv joints, especially on full lock was extremely common and often fresh grease and a new boot and clips fixed the problem.

[IanS16]

Nice one John

[Harman350z]

Brilliant information buddy, thanks for this.

 

Very detailed.

 

Now we need one for drop links

[Zugara]

Excellent post John. Cheers for the information submitted here.

[Husky]

no worries guys, hope its useful.

 

Brilliant information buddy, thanks for this.

 

Very detailed.

 

Now we need one for drop links

 

sadly i was already writing it just had to go to a meeting half way through.

[maz0]

Good post mate, very informative.

[UNABASHED]

Well done Husky!

[Husky]

Via PM from alex

The clicking noise on the rear axle is caused by the faces of the cv joint and the hub not marrying up correctly and a film of rust developing.

 

The grease and rotate procedure temporarily removes the click as what is done within this procedure is cleaning the rust off both faces, greasing both faces and turning the cv joint 180 degrees so that it is marrying up to the hub in a different position.

 

This is what Nissan do under warranty, which gives them a bit of time so that the car goes out of warranty. If you push you can get new drive shafts from them.

 

Nissan do not regrease the actual ball race within the cv joint as this is not the issue.

 

Any one that has actually regreased the cv ball race and found that the clicky noise has gone do not realise that the noise has actually gone because they have refitted the cv joint on a different spline hence inadvertently rotating the shaft albeit not by 180 degrees.

 

Nissan still supply the old cv joint over the counter to customers, in fact the same cv joint is fitted to the 370.

 

I supply an upgraded cv joint which amongst other things has a different angle on the face of the cv joint which marrys perfectly with the hub.

 

I think people are getting confused with the older type cars, especially FWD vehicles where clicky cv joints, especially on full lock was extremely common and often fresh grease and a new boot and clips fixed the problem.

[ATTAK Z]

All becomes clear Thanks Husky and ZmanA