Changing CV boots on IFS Isuzus.
Short Cuts
Authoring and Photography By:Dan Houlton
First Published: May 2000

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Splitting The CV Joint
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The ball race & cage is held in with a circlip.

The inner portion of the CV joint consists of the balls, inner race and cage.  They are attached to the half shaft and plunge within the outer cup (or outer race) of the joint.  To keep the joint together there is a spring steel circlip around the inner edge of the cup.  

If you look closely at the inside of the cup, you'll notice it's grooved where the balls go in.  Clean the grease away and insert a small screwdriver in along one of these grooves and it'll slip in underneath the circlip.  If the spindle is hanging outward freely, then the inner portion of the CV joint is pulled out as far as it can go and the balls are resting against this circlip.  

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After removing the circlip, the CV joint will pull apart.

Push in on the spindle slightly to remove the pressure from the circlip and pull the circlip out.  You'll notice that it is a full ring with a split in it and it's fairly easy to get out.  After the circlip is out, let the spindle fall back outward and the inner portion of the joint will pull completely out of the cup.  Raise the vehicle slightly with the jack so that the weight lifts off the jack stand under the lower a-arm.

If the joint doesn't come apart far enough to clear the brackets of the frame to pull the end up to work on, you can turn the steering wheel towards the side that you're working on to get more clearance.  This will push the tie rod on that side outward and allow the spindle to fall outward further to give the room needed.

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Use a screwdriver to pop the balls out of the cage.  Notice the snap ring holding the race onto the splined half shaft.

Looking at the inner portion of the CV joint now, the balls are obvious.  The cage is the outer cage that the balls are in, and the inner race is the inner sprocket looking thing that the splined end of  the half shaft slides into (in this case, "inner race" refers to "the innermost portion of the CV joint", not "the inner CV joint") .  I really don't remember where I got this nomenclature from, but that's what I call them.  They do have other names though so if you're following a maintenance manual as well, keep that in mind. 

First, remove the balls by inserting a small screwdriver from the end and prying them out.  The balls are a precision fit in the holes of the cage.  They are held in securely but will pop out fairly easily.  You'll notice that the holes in the cage are lined up with the grooves in the race.  Once the balls are out, turn the cage a few degrees so that the holes line up with the lands (raised portions) of the race.  Once there, the cage will drop down off the race.

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After removing the balls, the cage will drop down off the race.

Now look at the end of the half shaft and you'll see a snap ring holding the race onto the shaft.  Use a pair of snap ring pliers to remove this and the race will pull up off the half shaft.

Clean the old grease off all the parts and from the inside of the cup.  You don't have to sterilize these things.  Just get most of it off as it'll likely be somewhat contaminated from the torn boot.

Also, a studious reader might wonder why you pull the ball / cage / race apart instead of just removing the snap ring and the whole thing as a unit.  This is only so you can clean all the old and potentially contaminated grease from the moving parts of the joint.  You could also pull it off the half shaft assembled and use something like brake cleaner to clean the assembly out.

I don't show pictures of it here, but if you're replacing the outer boot as well, now is the time to do it.  It's actually pretty easy.  Just cut off the clamps for the outer boot and then remove the boot.  Clean the outer CV joint as best you can with paper towel or shop rags, then use a liquid solvent like WD-40 or brake cleaner to clean the internals of the joint as best as possible and blow it out with compressed air.

This will be a messy job, but the inner CV joint is supposedly a non-serviceable item and this is the only way to clean it.  I haven't examined one yet though to verify this.  There may be a circlip similar to what's on the inner CV joint that will allow the outer one to come apart.  One good thing though is that this is a non-plunging joint so it's much thinner and easier to clean out the old grease from inside.

Once it's clean, repack the joint with the grease included with the boot, slide the boot on (inner and outer boots are different so verify which one you're using) and clamp the big and small ends of the boot.  Details on this are shown below for the inner boot, but the outer will be similar and a lot easier too since the inner end of the half shaft is free to move around at this point.  


Installing The New Boot
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The new boot kit contains the boot, grease and two clamps.

The new boot will come with the boot, new grease for the joint and a clamp for each end of the boot.  Go ahead now and slip the new boot on over the half shaft.  Resist the urge to clamp the small end of the boot just yet.  Getting the big end of the boot over the CV cup is the hard part and it'll be much easier if the small end isn't yet clamped when you do it.

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The new boot and ball cage on the half shaft.  Big end of the cage goes up.

Re-assembly of the inner CV joint is just the opposite of how you took it apart.  First drop the cage down over the half shaft.  The cage has a big and a small end.  Make sure the small end goes down.  The big end needs to go up to slip up over the race.  If you get it backwards, it won't slide up over the inner race after you get it on so you'll have to remove it again to flip the cage.

Now slide the inner race back on over the splines of the half shaft.  If you look closely at the splines on the inside of the race, you'll notice that one side of the race is chamfered.  It looks like the splines are slightly cut down.  

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Notice the cut down splines in this end of the race.

This cut down end of the race goes onto the shaft  first.  If you get it the wrong way, it won't slide onto the half shaft far enough to get the snap ring on.  Now use the snap ring pliers to replace the snap ring and secure the race.  Don't forget this snap ring or you'll likely soon be buying a replacement half shaft assembly.

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Line up the cage with the inner race and pop the balls back into place.

Now slide the cage up over the inner race.  Turn the cage slightly if you need to until it slips up and over.  Line up the holes in the cage with the grooves in the race and insert a ball through the hole in the cage.  It's a tight fit, but will easily pop into place.  

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Squeeze the grease in over each ball until it starts coming out.

You should both hear and feel a little "click" as the ball pops in.  Go ahead and replace all 6 balls and the inner portion of the CV joint is back together.

Now comes the messy part.  Kneed the package of grease to get it mixed well and snip off one corner of the bag.  Press the open corner in over each ball in turn and squeeze out some grease until it starts coming out around the ball.  This way you know for sure the joint is well saturated with grease.

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The greased up CV joint.

Grease up the rest of the CV joint and the inside of the CV cup.  There's plenty of grease so use it liberally.  The extra can go down into the boot and into the CV cup.

Next step is to re-assemble the inner and outer portions of the CV joint.


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