Acceptable amount of rotational play in a CV axle?

[Fairtax4me]

Anybody know?

 

I've looked through several service manuals, text books for school, searched google, I can't find a specific definite acceptable amount of rotational play for an CV joint.

 

Kinda like backlash in a gear set. It has to have some amount of play. Too little play and the parts don't get lubricated properly, they overheat, damage occurs. Too much play leads to excess slop, wear.

 

If you can rotate a CV axle shaft and hear an audible click from the joint... too much play?

[forester2002s]

If you can rotate a CV axle shaft and hear an audible click from the joint... too much play?

In my experience, any rotational play is too much. You certainly shouldn't hear a click.

 

An involute gear set is different. Some amount of backlash is inherent in the design, so that the gear teeth can clear each other, as the teeth mesh.

[virginiaham]

as a mechanic, I'll accept some barely perceptible play in a customers CV joints, IF it isn't making noise or causing a vibration. There is always play on any mechanical joint, but it should be so slight that you can't feel or see it without a dial indicator.

[Fairtax4me]

Right, I'm trying to establish a measureable amount. Hundredths? Thousandths?

Though I'm not quite sure how I would measure it on these since the joint housings are totally round.

 

Having absolutely 0 play would cause binding. A very small amount of play allows for smooth articulation of the joint without causing excessive slop in the driveline, but shouldn't be obvious.

 

What I'm trying to determine is how much play can be considered normal before the joint starts to cause excessive driveline slop. Play in one joint may not be noticable, but if there is play in both inner and outer joints the effects start to compound. Now multiply that by 2 axles, 3 axles, 4?

[CNY_Dave]

If you can feel it but not see it- OK.

If you can see it- it's getting sketchy.

[MilesFox]

my 96 impreza is like this, probably almost 1/4 inch rotational play in the front axles. Sometimes you hear it cling when you put in gear. The PO had put the FWD fuse in thinking there is a problem, but the car drives just fine.

 

However, there is a corner of the front diff dipstick worn away as if it were hitting against something.

[idosubaru]

I've always assumed if they don't have drivability noises/vibrations they're fine?

 

Or i've always assumed if it's a Subaru axle anyway....if it's aftermarket i'm much more likely to move on and get a Subaru axle in there.

 

Technically speaking wouldn't it vary between:

1. inner and outer joint (CV verses DOJ)
2. front and rear

3. which style front inner joint - the one where the balls fall out as soon as you pull the cup, the one where the balls don't fall out when you pull the cup, and then the newer 2005+ style.

4. This may be more practical than technical but which model/vehicle - angle of the axles

 

Higher vehicles are less forgiving. I've put noisy/vibrating axles from higher (OBW/lifted Subaru's) on lower (legacy/imp) vehicles and they performed fine for years with never an issue.

Edited July 14, 2014 by grossgary

[Fairtax4me]

Technically speaking wouldn't it vary between:

1. inner and outer joint (CV verses DOJ)

2. front and rear

3. which style front inner joint - the one where the balls fall out as soon as you pull the cup, the one where the balls don't fall out when you pull the cup, and then the newer 2005+ style.

4. This may be more practical than technical but which model/vehicle - angle of the axles

I had thought about the type of joint possibly making a difference but the only type I can see being vastly different than the other ball type joints would be a tripod style.

 

I know the tripod joints can wear significantly to the point they start to bind with high mileage, but I cant imagine they have any more play than any other style joint when new.

 

 

 

Something interesting I found while digging around in the FSMs I have. A Subaru with a 5mt trans, it will have DOJ style inner joint on the front axles.

The rear axles also differ somehow from left to right.

 

With AT trans it will have tripod inner joints on the front axles.

Rear axles are the same with an AT.