A drive shaft has 2 CV joints, and inner and an outer. One of these allows the driveshaft to move in and out, so that the shaft can handle the change in geometry as the suspension moves. Some cars have it on the inner joint, some cars have it on the outer.

Which ones are the ones that move on the front driveshafts?

 

Usually... the in-out movement, lateral movement is accounted for by the splined joint into the gearbox/diff end and/or the spline into the hub(less common).

the drive shaft does not always have two joints, if it does its to accomodate the differance in alignment of the g'box/diff placement and the wheel hub position.
It may only need one cv joint in some cases.

The CV joints are made and fitted to allow movement in any direction (except lateral) of the driveshaft, whilst maintaining a rotational connection.

thats why there are CV joints and splines, together they allow movement in all directions.

Hope that helps.

 

Sorry, but that's simply not true. I've done plenty of engine and gearbox removals (in fact just done one on a VR4) and I've never seen a driveshaft with only one CV joint.

Here's a picture of an impreza front driveshaft:


(Oddly, by locating that image, I've answered my own question. The inner CV joint looks like the one that allows the travel inside the joint. The splines are typically locked in and require a tap with a hammer to dislocate them.

There are always two CV Joints on a driveshaft. The driveshaft has to move at each end to accommodate the suspension travel.

Here's a picture of a CV joint:


In the picture above (not a scoob) , it's inner CV joint, and you can see how the spider and three rollers can move in and out.

There is a reason for my asking. I'm building a project car which uses S14 rear hubs, and which will have an EJ20 in the back, using just the front drive from the gearbox to drive the rear wheels. I need to accommodate this travel somewhere, and the CV joints on the S14 hubs are where this travel is permitted. I'll be making driveshafts up which will take an S14 outer CV joint and a Subaru Inner CV joint. If both joints allow this travel, then I'l have a problem and will have to source a joint+stub axle from "something else" that doesn't, but which has the correct splines for the Nissan hubs.

 

not going to make an argument over this but i had Minis for some years and they do use the inboard splines as lateral movement, I was making a very general description about the assembly to someone who said they didnt know how it operated.
If youcant see how my description would work maybe you need to draw it.

thanks for the help by the way...