Z31 Axle Swap R200 CLSD - M2 Differentials

[CarJway]

Well, their are numerous threads concerning the binding of the stock Turbo Z31 axles when placed into an S30. This is when swapping a R200 CLSD from a Z31, with the billet adapters from Modern Motor Sports. Some say they are doing just fine, while others can barely get the axles in with the cages flipped. Well, I wasn't comfortable with the tight fit of the axles, and Jon pulled through with a set of axles that sits great in the S30. The length of the axles puts the CV in the middle of its travel, and doubt I will ever have enough power of coming close to breaking them! (stock length control arms) Discussion thread here... Overall, the construction of the axles is great. The splines fit into the Nissan CV’s with no extra play or backlash. Just what you would expect, as if these were the OE shafts. I haven’t driven on them yet, but I will be sure to update this thread once I do.

 

To some, swapping the axles might be common knowledge, but the pictures below might aid anyone doing this for the first time. This will also show how stout these axles really are. If you have any other methods, or pictures I may be missing, please let me know and I will adjust/add them.

 

Side by side comparison. (I painted the axles flat black)

 

After taking off the clamps.

 

Start with the outer portion of the axle. There will be a white/silver cap covering the inner portion of the CV. There is a snap ring you need to remove. I used a rubber mallet to tap the outer flange. It doesn't take much to get the cap off, so no need to get the sludge hammer out.

 

Once you have removed the snap ring, you need to remove the outer CV assembly off of the shaft. Again, using a rubber mallet will do the trick. One slide off by hand, and the other need a few taps. This will leave you with the inner snap ring. You can skip this step if you are using new boots. I already had new boots on the shafts, so I needed to get them off. Once you have taken the inner snap ring off, go ahead and slide off both CV boots.

 

Getting the inner CV off; this can be accomplish in a few manors. Using a pipe, and placing the axle in the pipe, and slamming the CV assembly down into the pipe OR using a dead blow hammer. Using the dead blow hammer, took 4-8 hits to get the inner snap right to give. Mind you I am 145 lbs, so with me holding shaft and hammering, I think this method works great. When taking off the inner CV, be sure to hit the inner portion. Otherwise, the outer cage will shift, and you will never get the snap ring to give.

 

You should now have both CV assemblies off the original axle. You should start with the inner CV; I wouldn’t put any boots on at this time, as they will get in the way. I didn’t take any pictures of this step, and it was probably the trickest step. You will need to take the snap ring off of the original inner CV, and transfer it over to the new shaft. I placed the inner CV facing the ground, and then inserted the new shaft into the splines. DO NOT just hammer away; the snap ring did NOT just give. My snap ring actually bent, and had to order new ones from Nissan. Once you have sat the shaft into the splines, use a small screw driver and push the snap ring into the groove of the axle. It has a beveled edge, which aids you to get it started. As you’re pushing the ring into the groove, apply pressure to drive the axle into the inner CV. You will feel when the axle has entered the splines. At this point, you can hammer the axle into the CV. It didn’t take too much to drive it in, and used a 2lb dead blow hammer to get it accomplished.

 

Before sliding on the boots, this would be a good time to add more grease. I used CV grease from Car Quest, which came in sealed packets. If you want to use some high performance grease, Redline makes a specific grease for CV’s I believe. Once the boots have been slid on, you can work on the outer CV. I did not find it necessary to flip the outer cages. I put my shafts back together with the cages in the original position. After tapping the outer CV assembly onto the new shaft, you will need to place the outer snap ring on. Once the snap ring is on, you can take your rubber mallet, and tap the white/silver cap back on. Again, it doesn’t take much to get it on, so don’t use your BMF hammer here.

 

You can now slide your boots on all the way. You will need new clamps for the axle side. (since these are decently thicker) I haven’t had a chance to put my new clamps on the boots, but will update the thread this weekend. Before setting the clamps on, I test fit the axles to ensure the boots weren’t being over stretched at my static ride height, and adjusted as needed.

 

Here is a visual comparison of the new vs. old.

 

Now, onto the axles in the car… A few shots of how they look, but most importantly the amount of travel now available. Since it is kinda tight back there, I tried to measure this as best as I could. With the CV fully compressed, we have about 7/8†to 15/16†of travel from the mating surface of the adapter. Since these housings have roughly 1 11/16†of travel, this leaves us with another 13/16" of travel outboard. On a stock control arm car, this places us somewhere in the middle of available travel. So if we do go with adjustable control arms, we should be able to adjust either way comfortably.

 

Edited November 18, 2011 by Carjway

[JMortensen]

Thanks for the writeup, I appreciate it.

[RB26powered74zcar]

Nice job on the documentation...

[CarJway]

For the boot clamps, I used the two sizes available from CarQuest. (Brand: Band-It) All they had was medium, and large; but it worked out great.

 

Taking the clamp, and wrapping it around the boot. Slip one end into the clasp.

 

Using the following tool from KD, (#3191) slide the end of the clamp into the tool. This will go into a slot on the tool, that will be used to hold the clamp during the tighten process.

 

Once you have gone hand tight, use a 1/2" socket to finish applying a bit more pressure. You will see the clamp slightly sink into the rubber, and shouldn't take much to do so.

 

Once satisfied with the tightness of the clamp, hold the lever that apples tension, and bend the tool over towards the clasp. When you have bent the clamp over, use the cutter integrated into the tool to cut the band. When doing this, be sure the bend you made doesn't come undone due to the pressure of the clamp around the boot. I had to catch it a few times... BE CAREFUL THE CUT END IS VERY SHARP!!! Ask my thumb, as it decided it wanted to donate blood all over my shop floor.

 

The finished product; take a punch/hammer and bend over the tabs that will hold the assembly all together. I took a dremel after I was all done, and grinded down the edges of the cut clamps. Mine were sharp, and didn't want to donate anymore blood later down the road...

 

Edited November 30, 2011 by Carjway

[rossman]

Nice write-up. Thanks for taking the time to put it together. I want to mention the axle configuration here since I just spent the last hour searching to verify which differential input axle goes on which side. Maybe it will save somebody some time in the future.

 

Drivers Side: short shaft + short diff input shaft

Passenger Side: long shaft + long diff input shaft

[JMortensen]

PM'd with Rossman about this a bit just to get it straight, but on my 300ZXT LSD the long side is the driver and the short is the passenger. Ross says he checked and it actually works the other way in his diff.

Edited February 18, 2012 by JMortensen

[alainburon]

PM'd with Rossman about this a bit just to get it straight, but on my 300ZXT LSD the long side is the driver and the short is the passenger. Ross says he checked and it actually works the other way in his diff.

I wonder why that is? Most of the write ups I have seen mention the driver side being the short shaft and the passenger side being the long shaft.

See attached document.

z31-cv-conversion.pdf

[JMortensen]

No clue. I have had mine apart, but I don't think the side gears would have the circlips in different positions. Externally the side gears are the same dimensions, and I wouldn't think they would cut the grooves in different spots if there wasn't a good reason. I would think that the difference is built into the carrier. Anyway, if anyone else doing the install wants to report back, maybe we can clear it up. All that's needed is to pop the inners into the diff and check.

[24OZ]

Thanks for the write ups and advice, it's given me the confidence to go ahead and do this and so far I've found it a very satisfying task!

 

I noted in the Parts microfiche for the Z31 turbo that there appears to be different part numbers for the grease used for the inner and outer joint? Why is there a difference, what's the significance of this? Can you recommend what different greases I should use and which ones for which joint.

 

Thanks.

Edited April 13, 2012 by 24OZ

[JMortensen]

I noted in the Parts microfiche for the Z31 turbo that there appears to be different part numbers for the grease used for the inner and outer joint? Why is there a difference, what's the significance of this? Can you recommend what different greases I should use and which ones for which joint.

I don't know of any reason why the two joints would need different lubricating capabilities, they're both the same kind of birfield joint. I would suggest you use an extreme pressure moly grease. I honestly don't think it makes that big a difference which moly grease you use, but Coffey has made a grease recommendation of Wurth SIG 3000, and I'm a fan of Wurth lubricants, so if you are looking for a brand name, I would try his suggestion.

[24OZ]

Just a point to make in case anyone misses it.....

 

Even though the ends look very similar, they are sided, if you look closely at each end you will notice either an I or an O, for Inner and Outer.

Edited April 16, 2012 by 24OZ

[JMortensen]

Even though the ends look very similar, they are sided, if you look closely at each end you will notice either an I or an O, for Inner and Outer.

Funny, I don't think I told the machinist which side was inner and which side was outer. The CV inner races are different thicknesses. I don't think you can screw it up, because you won't be able to get the snap ring or circlip in the thicker side. There isn't a huge difference and I didn't actually try to put the wrong side on and see if it worked, but I'm pretty sure that's right...

 

EDIT--Also the groove for the inner circlip is deeper and wider than the groove for the outer snapring.

Edited April 17, 2012 by JMortensen

[Oddmanout84]

Sorry, it's been a while...

 

This may be a dumb/answered question, but since these axles are custom fabricated, does that mean you can buy either/or 300ZXT/NA CV assemblies? From what I recall from previous writeups, the reason NOT to get 300ZX NA CV's was because they were too long. It would be nice if this negated the need to be picky about which CV's to source, or are there other differences between the models and sides they're installed on...

[JMortensen]

The custom shafts that I'm selling are for the 300ZXT shafts. The problem with the NA shafts is that you have to cut the boots off and then clamp them back on, and they're tripod design which isn't quite as strong. If you're buying my shafts, you still need a left and a right because the differential side of the CVs still have to plug in correctly and they have different lengths.

[RebekahsZ]

Just had a really fun drag racing night on John Mortensen's shortened axles with my LS2-powered 240z. No problems - what a blast! Thanks John, my second set has arrived: prompt delivery!

Edited June 23, 2012 by RebekahsZ

[RebekahsZ]

Went 7.2 sec and 96mph in the 1/8-mile on these. That is 9 runs with no problems.

[EF Ian]

Is there any solution to the shafts being too long now that M2 Differentials is no more? Does anywhere else make them?

[JMortensen]

Talk to Joe @ Chequered Flag. He is considering doing another run.

[EF Ian]

Thats great news if he decided to sell them.

[RebekahsZ]

PM SunnyZ - he has had a set made by the Drive Shaft Shop and should be able to tell you how to contact them. They charged $600, which is $100 more than JMortensen at M2, but they did all the labor and provided all the small parts like boots. In my mind, having done this, that is $100 well spent!