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CV Axle Discussion


kj280z

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Jon,

If you were able to produce axles of the correct length for a reasonable price I'm sure you could sell a few the problem may be finding the 300ZXT CV ends if you don't already have them.

This brings up a question, what are the CV ends on a 300ZX (Z31) non-turbo? Are they the same as a 280ZX or a 300ZX Turbo? Reason I ask is a buddy of mine has a pair of non-turbo axles I'm trying to talk him out of but if they have different joints then I don't want them.

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Jon,

If you were able to produce axles of the correct length for a reasonable price I'm sure you could sell a few the problem may be finding the 300ZXT CV ends if you don't already have them.

This brings up a question, what are the CV ends on a 300ZX (Z31) non-turbo? Are they the same as a 280ZX or a 300ZX Turbo? Reason I ask is a buddy of mine has a pair of non-turbo axles I'm trying to talk him out of but if they have different joints then I don't want them.

 

I believe the 300zx NA axles have the same bolt pattern as the 280zxt CVs so the MM 280zxt adapters would be a popular seller if this was the direction - plus the 300zx NA CVs are easy to find and very cheap

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I also would be interested in a set of shortened 300ZXT shafts. At the stock ride height, they were already a tight fit and now that I have lowered the car, they certainly bind. I am looking locally for a axle shop to solve the issue, as this is holding me back from getting back on the road.

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What about using the Non Turbo 300 Axles and having the spline cut longer into the existing shaft so the bearing cage can move higher on it .This would effectively allow the excess to be cut off leaving a shorter axle without making a new center shaft all together . The Diff side is the same as all 300Zx cars have R200 rears and the wheel side cage has the exact 6 bolt pattern as the ZX Turbo Axle so they work with the MM Adapters .

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What about using the Non Turbo 300 Axles and having the spline cut longer into the existing shaft so the bearing cage can move higher on it .This would effectively allow the excess to be cut off leaving a shorter axle without making a new center shaft all together . The Diff side is the same as all 300Zx cars have R200 rears and the wheel side cage has the exact 6 bolt pattern as the ZX Turbo Axle so they work with the MM Adapters .

 

Yep! That's exactly what I've been saying! And I'm selling a set of 280zxt CV adapters in the Parts for Sale section for anyone who'd like to give it a shot!

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Cutting the splines higher on a 300ZX shaft might not be possible. I know the ZXT shaft has a shape to it, that I'm pretty sure would make that impossible. Also, by the time you've cut the splines, you're already doing most of the work to make a new axle. I can't imagine this saving a lot of money, and if you have the ability to cut splines, you probably have the tools to make your own axles...

 

Just a quick update on the custom shaft thing, I'm getting a bit of runaround. Still trying to make something work.

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Rolled or cut splines is a kinda silly thing to argue over. YES, rolled splines will be tougher. But I can't think of a single occasion where I've personally seen splines stripped off of an otherwise healthy shaft. On your typical 4x4 or drag racer axle they always shear right where the spline meets the shaft, usually after some twist in the shaft itself. As I say on the M2 website, if you're worried about whether the splines are rolled or cut, you should just buy a larger axle shaft with a higher spline count.

 

I went and pulled one of my CV's and took a picture, and you can see why cutting (or rolling) the splines further isn't an option. The splined part of the shaft is 1.150", the section immediately after it is 1.068". So at least on a 300ZXT CV shaft, it's not going to work.

post-553-036229400 1309303551_thumb.jpg

Edited by JMortensen
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Rolled or cut splines is a kinda silly thing to argue over. YES, rolled splines will be tougher. But I can't think of a single occasion where I've personally seen splines stripped off of an otherwise healthy shaft. On your typical 4x4 or drag racer axle they always shear right where the spline meets the shaft, usually after some twist in the shaft itself. As I say on the M2 website, if you're worried about whether the splines are rolled or cut, you should just buy a larger axle shaft with a higher spline count.

 

I went and pulled one of my CV's and took a picture, and you can see why cutting (or rolling) the splines further isn't an option. The splined part of the shaft is 1.150", the section immediately after it is 1.068". So at least on a 300ZXT CV shaft, it's not going to work.

 

What CV's are shown in that pic? Are they the z31 NA shafts?

Edited by kj280z
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  • 2 weeks later...

I've finally made some headway here. I've read what wheelman suggested, and he was nice enough to give me lengths via PM and I've looked at my own car as well. Wheelman suggested putting the driver's side shaft on the passenger's side because it is 1/2" shorter. I tried to relate these measurements to my own car, which has the chromoly companion flanges from MM (which give an extra 3/8" clearance AND I have 1/2" longer than stock control arms). Based on what I saw on my car, I have some doubts that running the LH axle on the RH side gives enough clearance. If it does, it's got to be really tight, very close to bottoming. On my car, the passenger side is about 1/8" from bottoming out with the stock passenger side shaft in there at full droop, and that is with 7/8" more room than would be available on a car with regular length control arms and the wider MM tig welded adapters.

 

Today I'm going to take my springs out, put stock length control arms in and check the measurements at full droop and full bump, and see where we need to be to put the CV shaft in the middle of the outer race. I expect that I'll come up with a shaft length that is an inch or so shorter than stock for both sides. We will also finally have proof of where the CV shafts are shortest, whether that is at full droop or full bump or level. We'll see. I'll try and post pictures this afternoon.

 

I've sent my passenger CV shaft to a shop with the most reasonable prices so they will have the spline size and groove locations. They are going to make chromoly CV shafts to whatever length we need, and I will sell them through www.m2differentials.com. That means you guys have a phone number to call if there is a problem, I actually respond to emails, M2 takes credit cards so you don't have to screw with Paypal, etc. We will also have a totally new stub and CV swap that we will be releasing in a couple weeks. It will have some pretty major advantages over what is currently available, I'll keep you all updated as that gets closer to happening.

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This is awesome John, that would be a great solution to this problem.

 

Also, I know this is a little away from what we've been discussing and you guys most likely already know about it, but Techno Toy Tuning also offers a full up rear end conversion that gets rid of the stub axles (weak point) and allows you to run all kinds of CV axles and differential from donor cars which include the S13, S14, S15, R32, R34, Z32, Z32TT and Q45.

 

Of course, this isn't a lightweight upgrade such as the Z31T CV axles, but it is an option, and a wise one if you were to ask me. You would have no problem finding axles this way.

 

Rear End Conversion information:

 

http://technotoytuning.com/productdetail.php?p=863

Edited by jacob80
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Rolled or cut splines is a kinda silly thing to argue over. YES, rolled splines will be tougher. But I can't think of a single occasion where I've personally seen splines stripped off of an otherwise healthy shaft. On your typical 4x4 or drag racer axle they always shear right where the spline meets the shaft, usually after some twist in the shaft itself. As I say on the M2 website, if you're worried about whether the splines are rolled or cut, you should just buy a larger axle shaft with a higher spline count.

 

I went and pulled one of my CV's and took a picture, and you can see why cutting (or rolling) the splines further isn't an option. The splined part of the shaft is 1.150", the section immediately after it is 1.068". So at least on a 300ZXT CV shaft, it's not going to work.

 

Agreed, there is no argument which method is more structurally sound. The reason those shafts shear right past the splines is due to the transition from spline to smooth shaft at the highest stressed area in the shaft. Work hardening the material by rolling the splines improves the situation.

 

Either way, I'm glad you are doing what you are doing for the Z community.

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Thanks Rossman. I don't want to get too far out in the weeds, but the real question is how much benefit it provides, and the axle manufacturer that I worked for years back who made 1541H and 4340 chromoly shafts with rolled and cut splines said the difference was negligible. I've looked online and found no hard numbers, but lots of speculation either way. I don't know if the splines on the axles I'll be selling will be rolled or cut, but I will find out and advertise it so that you guys know. I do know that there will be a lifetime warranty and they'll be chromoly, so the material is already ~40% than the stock alloy. I am sure that the upgrade in material is worth far more in terms of strength than rolling splines on the stock material would be.

 

OK now for some info.

 

I can confirm that CV lengths are shortest at full droop as has been widely reported previously.

 

Available CV travel on the 300ZXT CV's is 1 11/16".

 

Total change in length on CV shafts on my car from full droop to full bump is 3/8".

 

I was measuring from where the retainer snap ring would rest against the CV on the inner to the CV shell on the outer, as the center of the CV is right at the same length as the shell at full extension, and the cage gets in the way so it's much easier to measure the housing.

 

Here are my measurements:

 

Driver's side

Bump: 11 3/8"

Level: 11 1/4"

Droop: 11"

 

Passenger's side

Bump: 12"

Level: 11 7/8"

Droop: 11 5/8"

 

Now this is not yet the length of the shaft that we need, because it is the measurement of the shaft when totally topped out, and it doesn't include the length added by the splines. The splines add 2.5" (1.25" per side). Since the amount of travel used is so little, we should be able to make these numbers work for both the billet flanges and the welded flanges. Add another 13/16 or .8125" of length to put the CV in the middle of its travel. Then subtract .375" because I had the MM companion flanges which give 3/8" more space. So basically take my measurement and add 2.9375" or 2 15/16" for a total length that would be accurate on a Z with stock control arms and Ross's welded CV adapters.

 

We can use the level measurement because it is pretty close to the middle, and we get a length of 14 3/16" for the driver and 14 13/16" for the passenger side. This is roughly 1" shorter than stock on the pass side and 1 3/16" shorter on the driver's side.

 

According to wheelman, the stock driver's side shaft is 15 3/8" long. The real question is whether that driver's side will work on the passenger side. So let's reverse the numbers a bit. Take the minimum pass length of 11 5/8", add 2.125" to it and you get 13.75", add in the total travel of 1.6875" and that is the max allowable length of the shaft before it bottoms, and you get 15.4375". So by my calculations, putting the driver's side CV on the passenger's side clears by .0625" if you have the MM welded flanges. Just based on variations in the chasses, I think this is cutting it a little close. That's not considering bushing deflection, etc.

 

So I would say that if you are running MM's billet companion flanges, you can run the driver's side CV on the passenger's side. If not, you should buy both the driver's and passenger's side CVs.

 

I have forwarded the lengths to the axle shop and I will let you guys know when they are available for ordering.

 

These shafts will fit 300ZXT axles ONLY. If you have Ross's kit with 280ZXT axles, you have a couple of problems. First is that those CVs are pretty hard to get apart from what I understand. I haven't done it myself, but I think you need to cut a crimped band off of the outside if memory serves. Not that big a deal, but when you go to put them back on... ??? If it is possible to disassemble and reassemble those shafts, if there is some trick to it, I'd love to hear about it. I can't do the measuring on my car because I don't know how far the CV adapter sticks out from the stub axle, but if I could get reliable measurements from somebody, the same sort of CV axles could be made to fit. I think the assembly/disassembly is too big a hassle for most people.

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I've already ordered a prototype set along with the other completely new axle setup, they should be here in about a week and a half to 2 weeks. When I've verified that everything looks right, then I'll make them all available at the same time. I still have to work on pricing and I need to figure out exactly what the cost is as delivered before I can set the price.

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I have to double check when I actually get the parts, but the price looks like it is going to be $495, no shipping charge. I called a bunch of places and that was the best I could do.

 

The specs are there, so anyone can take those and go get their own quote if they like. All I ask is that if you come up with something cheaper, let me know so that I can try and get a better deal for everyone else here.

Edited by JMortensen
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