300 ZX Turbo CV shaft disassembly and reassembly by JMortensen

11 minute read

300 ZX Turbo CV shaft disassembly and reassembly

Compliments of JMortensen @ www.hybridz.org

CV shafts aren't particularly hard to disassemble, but there are a couple of tricks that it really helps to know ahead of time. This write up will give a step by step and hopefully make the process a little easier for first timers.

1. Remove the outer CV boot. I didn't take pictures of this, but the way I like to do it is to take a pair of dykes and shove one side of the cutter under the CV boot clamp (without cutting the boot). Then squeeze and twist the handle back and forth and the clamp will work harden and snap. 

2. Remove the snap ring from the inside end of the CV housing with a screwdriver. This will allow the outer CV housing to slide off, exposing the inner race, ball bearings, and cage.

3. At the end of the shaft you will find an outside snap ring. Remove it with a pair of snap ring pliers. Side note: This picture shows the outer CV cage in the standard position.

This is what it looks like when flipped per the Modern Motorsports instructions. You can see that flipping the cage doesn't buy much space because the axle protrudes nearly as far out as the cage does.

4. Once the snap ring is removed, the inner race with the cage and balls should all slide off as an assembly by hand. The balls are captured by the cage, so they can be gently pried out with a small screwdriver or a pick.

5. After the balls are removed from the cage, twist the cage 30 degrees, and it will pull straight off. This picture shows how the race lines up with the cage in such a way that it is prevented from coming apart without that 30 degrees of twist. The cage on the left will not come off, as twisted on the right, no problem.

6. Remove the inner snap ring that locates the CV inner race so that the boots don't tear while trying to pull them over the sharp edge of the snapring. With the snapring removed, you can slide the outer boot off of the shaft. 

7. Take the inner CV boot clamps off and slide it off of the shaft as well.

8. It is time to remove the inner CV. I've done this job a number of times, and I've never had too much trouble. I clamp the CV shaft firmly in a vise, and then hit the inner CV housing with a dead blow hammer. I hold the splined end of the CV and usually 4 or 5 good whacks on the housing and the circlip will pop out of the CV and it slides right off. Others have reported that they just cannot get the CV joint off. One alternate method is to take a piece of square tubing that is 2" and 2' long and slide the CV shaft into it, and then throw it at the ground square tube first. I've never used that method, but people say that it works.

9. Once the inner CV is off the shaft, clamp the HOUSING (not the shaft itself) in a vise. In order to get the ball bearings out, you need to twist the race inside the housing. They are usually pretty stiff. You can put the CV shaft in to get the inner race twisted a bit, and I usually find that after I get it move it until the CV shaft hits the housing, I can move it the rest of the way by pushing down on the low side and pulling up on the high side with my fingers until the first ball comes out of the housing. Once it is out, use a small screwdriver or a pick to pop the ball out of the cage. I've found that it's usually easier to remove the balls in a star pattern than it is to roll the inner race around to hit the next ball to the left or right. In this particular picture I was able to move the race enough to remove two of the ball bearings at once.

10. Once all the balls are out, you need to get the cage and inner race out. The cage has two larger windows. By aligning the longer windows vertically with the races, you'll find that the race will slide right out of the housing. Interestingly, the inner balls are slightly different than the outer ones. The inner balls are slightly larger.

11. The inner cage comes out by means of those longer windows as well.

12. Once you have all the parts disassembled, clean everything and inspect for damage and wear. The main thing to look out for is pits in the races and chips on the ball bearings. CV bearings from a 25 year old car probably won't be perfect, and they don't need to be absolutely flawless. If they have significant pitting, replace the joint. Junkyard gold tip: early Pathfinders (90-93 and possibly other years) use the same joints with a much shorter shaft, and since they are front driveshafts in a 4wd application that is rarely used, they're often in nearly unused condition.

13. Time to reassemble! Hopefully you're now installing your CV joints on a set of custom chromoly CV shafts from M2 Differentials so that you can use them in an S30 without the CV shaft bottoming. The first part of the reassembly is the inner CV. Slip the inner race into the cage and again align the long slots in the cage with the housing so that the cage and inner race are installed in the housing with no ball bearings. Then, just the opposite of how you removed the ball bearings, re-install them into each of the windows until all 6 are back in place.

14. Greasing the CVs. Greasing CV's is kind of like greasing wheel bearings. Just as you do not pack the entire spindle with grease out to the dust cap, likewise you do not need to pack the entire boot with grease either. On the inner CV, you cannot grease the CV joint until it's entirely assembled. Once it is assembled, I pack grease into the bearings and into the hole where the shaft plugs in, trying to get grease into all the little spaces. When you insert the shaft, some grease will be pushed out, but this is not a problem. The FSM specifies 4.06 - 5.47 oz of grease.

15. Installing the shaft into the inner CV race. The circlip groove is deeper and wider than the snap ring groove at the outer end, so it should be easy to tell apart. If you took the circlip off to clean the shaft or because you need to transfer it to your bitchin new M2 shafts, now is the time to do it. The circlip is WAY too big to fit tightly to the shaft. When you have the circlip installed, it will hang well off to the side of the shaft.

16. This is the biggest "trick" to the reassembly. If you do not "tuck in" the circlip and try to hammer the shaft in, you will wreck the circlip. These following two pictures show what it SHOULD NOT look like as you begin hammering the CV shaft into the inner CV.

17. This picture shows HOW IT SHOULD LOOK. Apply a little pressure on the shaft into the inner race and tuck the circlip into the groove with a small screwdriver. Then without letting the pressure off, hit the end of the CV shaft with a dead blow hammer. It shouldn't take a lot of force to compress the circlip and get the shaft to slide into the inner race. If you find you're hitting it really hard and it's not going, the circlip has moved. Ease up, start over, tuck in the circlip, and hammer in the shaft.

18. Apply a very light coat of grease to the shaft, slide the inner CV boot onto the shaft and work it into position. You could have put the CV boot on the correct side earlier on, but I like to do it at this stage so that it doesn't get in the way. Even with the thicker M2 shafts, it shouldn't be difficult to slide the boots across the shaft.

19. Slide the second boot and the outer CV race onto the shaft.

20. Re-install the inner snap ring if you're using stock shafts, this step is unnecessary if using M2 shafts. 

21. Re-install the cage onto the race and the ball bearings into the cage. 

22. Re-install the inner race/cage/bearing assembly onto the CV shaft and install the snap ring. Now you can decide whether to flip the race for extra room. If you're using stock shafts on an S30 chassis, I don't think it does enough to alleviate the binding issue. If you're using M2 shafts, I don't think it is necessary to flip the race at all, but it probably won't hurt anything either.

23. Greasing the outer CV. Same principle as the inner here, you want the grease to really get into all the bearing surfaces, but there is no need to fill the entire 3" deep CV cup with grease. I would put maybe an inch and a half of grease in the bottom of the outer race housing and set it down on a workbench, and then plunge the bearing into the grease. This should pack the grease in much the same way that a bearing packer forces grease through a wheel bearing. The FSM again specifies 4.06 - 5.47 oz of grease. If you try to push the grease filled housing onto the shaft you will likely pop the sheetmetal cap off the end of the outer race. No big deal, it can be tapped back on with a small hammer.

24. Reinstall the large outer snap ring.

25. Reinstall the outer CV boot. Since the M2 shafts don't have provisions to locate the boots, the dimension listed in the FSM is 3.575" from one end of the boot to the other at rest.

26. Install CV boot clamps.

27. When installing the CV shafts into the diff, they need to clip in. If you cannot push by hand hard enough to get them to click into place, carefully tap with a dead blow hammer around the edge of the inner CV housing (careful not to tear the boot).

28. Bolt up the inside end of the CV to your companion flange. The bolt torque specified in the FSM is 51-58 ft/lbs.

That's it. This is not a difficult job, but it is a greasy mess. Gloves, a roll of paper towels, and a can of brake cleaner are good to have on hand before you start in.