jverz

This is what I got for my birthday! Work to do on my car!



So riddle me this: I understand the advantage of getting the single piece drive-shaft. From what I see about these cars, however, is that they're very well engineered already. Who am I to go against the guys who should know a lot more about the car they built than I do?

What I'm asking is: Why was the car made with a split shaft? What problems will I run into with a single piece drive-shaft? Are there clearance issues?

bojo68

1. Because Engineers know that the 2 biggest factors that raise hell with drivelines are speed and length. 2. Possible waveform deflections that the only evidence that you'll know of is broken parts.(think about all those grotesque looking weights you've seen hanging off the rear of tranny's from factory's. That's part of some people's cure for what shouldn't have been.) 3. Well, it certainly looks like there are clearance issues with yours. I'm not so sure I follow all the supposed benefits of a one piece, aside from weight and part#'s. Generally, a stock one can be fixed for less than a modified one can be fabed.

jverz

the clearance issue seen there was actually due to the cup around the bearing breaking apart. the driveshaft was riding on top of the heat shield.

I know I can repair this for far cheaper than another driveshaft, I just want to know if there's been any issues with a single piece, or was the reason for the split shaft nothing more than cheaper balance? I'm an engineering student so my mentality is if something fails you don't replace it with something that will fail again later. You eliminate the problem from ever occurring again. Plus the drive shaft I'm looking at is a third the weight of OEM.

So my question actually is: Has anyone had a problem installing and running the single piece drive shafts?

Goofyz

Eliminating the carrier bearing is a good way to avoid having it fail again. The single piece drive shafts are a good substitute. I have one in my car and the only "difficult" part is getting the hex bolts undone without the proper length tool. Other than that the single piece saves weight over the stock two part "propeller shaft." I am not 100% sure about why the engineers used a heavy two part shaft except perhaps for the same reason that BMW uses them on their bikes. Smoothness. When you replace your driveshaft make sure you check your transmission mount for damage. When the back of the tranny is loose it can hurry along the failure of the carrier bearing assembly.

Carrier bearing is about $120.00 to replace you can get a decent aftermarket driveshaft for about double that price. Good luck.

chicopriest

Must be the season for carrier bearing failures. If you stick with the factory drive shaft just be sure to mark and replace the driveshaft exactly as you took it apart. If you drive with an unbalanced drive shaft you'll end up like me.

https://www.zdriver.com/forums/300zx-z32-forums-7/transmission-front-assembly-question-28911/

ZLover4Life

The OEM unit is 2 piece to reduce NVH.



And before you ask... http://en.wikipedia.org/wiki/Noise,_..._and_harshness

jverz

i ordered the single piece drive shaft. it's already been shipped, in fact. I understand Nissan would want to eliminate NVH, but I still think they could have just made better drive shafts instead of going the cheap route.

The front shaft was pretty banged up and i wasn't about to buy another one for $600; so lets hope this one from AMZ Performance is nicely balanced. I can't believe shipping was only $20.

ZLover4Life

"Going the cheap route?" LOL Yeah, it's cheaper to make two steel tubes and then design a carrier bearing to reduce NVH than to design and balance a single tube...

Ultimately, Nissan engineers deemed the required length to be too long for a 1-piece. And this is why lots of people who have gotten 1-piece driveshafts have had to return them until they finally got one that didn't vibrate. Hopefully it doesn't happen to you, but know that it's a possibility.

KasbeKZ

also, a lot of people forget to try clocking them. you don't know which way it will work until you try all 4 positions. so if it vibes at first, clock it. there will def be just a tiny bit of noticeable noise/vibe, but i never clocked mine and it seems to have gotten less and less brutal as it's been on. not to say it was bad to begin with. good choice on the 1-piece. the old shafts are NOT easy to fix. u-joints that can't be replaced are the second worst aspect of the car IMO. right after the windshield wipers wiping after you turn the switch off. hate that.

napoleonzheking

If that CB up there was an epic failure... what is not resizing pictures before you post them? An epic epic failure?

Goofyz

That people who lower, stiffen up, and increase power over the stock Z think that a little NVH caused by a single piece driveshaft would bother them. The 300zx was a Luxury sports car, it's what the x stands for. If you have already modified your Z by putting on an exhaust; intake; aftermarket suspension; racing clutch; lower profile tires; bigger rims; then go for the lighter, stronger single piece driveshaft. You might also want to get the stiffer transmission mount done while you are down there. The Nismo grade replacement is fine even going with the stock one although more expensive is probably fine as well.

If you want to keep the Z a luxury sports car then keep the center bearing, it is after all about 20 lbs. heavier than a good single piece.

domsgarage

Pretty much why I love this guys responses.

domsgarage

/ i have a single piece, love it, no vibrations, no noise, none of that NVH.

bojo68

Heh, I shorten one piece ones when I do engine swaps. I cut them with a skill saw, grind the weld off the yoke, peel the tube back, and then pound the yoke back into the shortened piece, and weld it up. One time I didn't have a welder handy, and drive it for 2 days without welding it. Never had nvh problems, but never went over 120 either.

Waiting for Hoov to say I've never done this either.....