when are ZXT Half Shafts necessary?

[Majik16106 0]

Just need a quick answer and Ill delete this thread so it doesnt take up space. At what power level are 280zxt rear half shafts needed on a 240z?

[Ivan 0]

don't delete it afterwards, I will be interested in this as well

[Gav240z 230]

Not 100% sure but they are necessary after you break your half shafts a couple of times.

I'd say anything around 300-400HP will make them cry and give up but that's just a guess.

:classic:

[2ManyZs 1]

If you go V-8, RB, or the Supra Turbo you would want an R-200 and the cv joint half shafts, anything less the R-180's and stock half shafts will be all you need.

It's not so much the HP that would kill them, it's the torque of whatever you install that will hurt them.

[RPMZ 0]

When I had about 330hp at the flywheel I broke them 4 times in 3-4 months. I tried to be gentle with them but they would break even when acceleration on the roll.

However my car is turbo, therefore produces a lot of torque which doesn’t help. When I put in the 280zx CV shafts I could change gears without stress. Definitely one of the best mods I’ve done, other than RB25DET g/box.

:classic:

[Ivan 0]

is there less stress on the shafts at higher speeds as opposed to taking off?

also if the shafts / diff / u joints were in line wouldn't it hold up a lot more?

also also wouldn't there be less stress if you were running an lsd?

[That Ozzy Guy 39]

Hi guys.

About an hour ago I busted up my first half shaft. There was a scary moment there when I thought it was the diff. So it's a long weekend and my car is off the road. Bleh.

I'd like all those questions answered too Ivan.

I have a feeling that I've got the 280ZX CV's but I can't tell. I'll get some pics tomorrow (too dark now) and gauge the full extent of the damage.

How much am I looking at for the 280ZX CV half shafts anyway?

Cheers

[Gav240z 230]

I had a look at the photo's of under your car and can almost be 100% positive there the 280zx CV unit's on there.

It's pretty hard to explain the differences but if I can find some photo's of what halfshaft uni joint type look like I'll upload em'.

Must be putting out alot of torque to bust those up, so what's it like driving a v8 Z as oppose to the inline 6?

[Gav240z 230]

The closer zoomed in shot of your car has changed my mind they are Uni joints which is a good thing because I don't know what you'd do if you were busting up CV's .

Anyone else wanna confirm this?

[That Ozzy Guy 39]

Hey Gav. You are right, they are Uni's. Here's a photo.

Originally posted by Gav240z

Must be putting out alot of torque to bust those up, so what's it like driving a v8 Z as oppose to the inline 6?

You can't really compare the two. It's a totally different ball game. It's like sleeping with a fat woman and sleeping with a gorgeous sheila. You'll come either way but with the hot sheila you'll enjoy it more and it'll be over faster. Umm, does that make sense?

So how much are one of these Uni's?

[That Ozzy Guy 39]

While we're at it, how much for the CV's? Might as well upgrade it now.

[Gav240z 230]

George the good news Uni joints are cheap and the halfshaft ones are easy to remove and replace no problem.

I remember paying $20 each for them the hard part is removing them but yours are broken so they might pop out.

I've never upgraded to the CV's but I believe they need to be shortened to adapt to the early Z's.

I think someone mentioned something around the $200 mark to me but I can't confirm this...

So what happened when it broke? I've never broken one could you still drive it? :classic:

[That Ozzy Guy 39]

The whole story.

I dumped it in first about half an hour before it broke off and I heard a loud bang from the back. This was the initial crack but the uni held on so I drove it home. I drove for around 3km before the half shaft came off. I was at the lights and was taking it very easy when all of a sudden I heard a bunch of crunching which I thought was the diff gears. The car came to a stop naturally and trying to move it again was painful to say the least. The shaft would just turn and hit stuff around it. Once we got it on the tow truck we realised it was the shaft and not the diff. My night and mood improved after that. :classic:

I think the wise thing to do would be to upgrade them to CV's in my case before it happens again. Any help on how I go about doing this would be fantastic.

[sjcurtis 0]

George,

sorry to see the results of more bad luck for you. I am glad to see you are running the R200 so your half shafts will be easier to get. As far as the mod goes you have all the contacts on your supplier list, use the phone, someone will be able to set you right. For the rest of us please post the fix, the shop and the cost, I think over half the Aus readers who use thier gas pedals would benefited.

Good Luck

Steve

[Ben 2]

Hey George,

Are you aware of the maintenance history/condition of you 1/2 shafts (and all driveline uni's)?

My dad lunched a uni on the racetrack in his 1600 a few months back - but it was the only remaining unit from new.... So he wasn't too upset.

If you haven't checked your uni's I'd be replacing them all & taking it from there. I was putting 250HP thru a stock setup for a few years with no hassles. (And there's more of that to come)

But, if they were fresh - what brand were they?

Then again, having just looked at your gallery, a CV upgrade may not be such a bad idea....

[That Ozzy Guy 39]

Originally posted by Ben

Hey George,

Are you aware of the maintenance history/condition of you 1/2 shafts (and all driveline uni's)?

I can't really answer that question but I'd say they were fresh in 1991 when the car was built. That is unless they had been broken after that and replaced. *shrugs*

With some help from my father I took the uni and shaft out today. Wasn't as hard as I thought it would be. Here's some pics.

Now I need to know how to disconnect the uni from the shaft?? I've taken out the clip but I hit a brick wall after that. I found a thread about it here so I'll try it out another day. http://www.classiczcars.com/forums/showthread.php?s=&threadid=6124&highlight=half+AND+shaft

[That Ozzy Guy 39]

Another pic

[Ben 2]

Well you certainly lunched that one!

Do the stampings show a brand name?

The long & short of uni removal is lots of lubricant & elbow-grease.

[That Ozzy Guy 39]

Originally posted by Ben

Well you certainly lunched that one!

Do the stampings show a brand name?

The long & short of uni removal is lots of lubricant & elbow-grease.

The launch must have clean broken the uni and then the force of driving it must have broken the other end and it poped out.

Here's a pic with the brand name. The bottom line which is hard to read is GM8.

[Ben 2]

If it has a grease-nipple fitting (it look like it has) then it's an aftermarket uni.

Some aftermarket uni's are weaker than the factory ones.

Try CBC for a replacement & let them know how tough it needs to be!

[That Ozzy Guy 39]

Yeah it does have a nipple. It actually broke off so now there is only a spring hanging from the hole. Always wondered what was inside the nipples.

I'm thinking I might just replace both sides with CV joints Ben. Will cost me more but at least I don't have to worry about it anymore. If I can find a cheap uni I'll whack that on for the time being so I can drive the car untill I'm ready to convert it.

Cheers

[sjcurtis 0]

Hi guys,

that uni failed from lack of grease not brute force. If you look at the plate end one of the bearing caps has been working(red brown dust around the edge) as the needle rollers inside sarted to get hot and lockup, starting to fail. George you were just your lucky self again, I could have jumped in the seat and dumped it with 6**** on the TACH with no fail then you would try and bang. It was an age related failure just grab a good drive shaft check the uni's and throw it in. Work the mod out to CV's in your own sweet time.

Oh check all your unis feel for any movement look for any sign of something diffrent if you are not sure post the pics and we can check for you. If you do go for new uni joints, I agree with Ben go quality, your suppliers will know.

Cheers

Steve :classic:

[Ben 2]

Indeed - every uni that I've replaced has been full of dust - dust that used to be needle rollers.....

Remove the other 1/2 shaft & the tailshaft & inspect the whole lot.

On 2nd thought - replace them all & get the tailshaft balanced, install a loop while you're at it.

Generally speaking, the splined section of the 1/2 shafts will twist before the units will break (seen it).

[That Ozzy Guy 39]

Well that is certainly interesting to know. Thanks guys.

How often should they be greased up?

[That Ozzy Guy 39]

Steve, here's a pic from the other side.