280ZX Turbo CV Shafts

[johnymd]

Johnymd - Dave J has described exactly how to do the conversion, but you should note :-

a) The 260Z Half Shafts have a different number of splines to the 240Z and will not fit the 280ZX Flanges, so you will need to source a 240Z set;

b) The newly modified setup to the nearside needs to be as thin as possible in order to fit the Tripod type Driveshafts into place ( because of the added width of the R200 Diff ). Even so, you will think that they will not compress enough to do so, but indeed they will - though you may need to remove the studs first and then tap them back into place afterwards to secure the shafts.

The reason I've bought 260z stub axles and matching companion flanges is the higher spline count and I've read they are stronger.
You wouldn't happen to have any dimmensions for the finished companion flange?

Go have a look at this conversion package as this is what i am using.

I have emailed them a couple of time now about shipping to the UK but never had a responce and their ordering system doesn't cope with outside the USA. If some has a set for sale I'd be interested though (I think you need to go R230 and sell be yours!).

still running standard 240z shafts with UJs and using avon very soft compound hillclimb slicks.
In 15 years of running the car I have only had 3 UJs break only one of these was on a very aggresive start. The othe 2 went coming out of a corner.
I have seen numurous CV jointed drive shafts break on much lighter cars
In my opinion there is no need to change the shafts. The engineers seemed to know what they were doing when they built the cars back in the 70s

Good info and I am really tempted to stay with the UJ's, just don't want to be wrrying about braking one and be stuck somewhere. I value your opinion so would you say the standard UJ's are as strong as CV's? The other fly in the ointment is my UJ's are old and probably seen better days. Plus the fact I already have the parts to do the conversion, just need to find someone to do the companion flange mod.

Thanks for all that contributed.

 

[ben240z]

brand new UJs on the shelf if you decide to stay standard

 

[Rob Gaskin]

I know people may get a bit fed-up of my posts as they are very predictable but here goes:

I've only ever had standard shafts, never had a problem - I've not even dismantled/greased them! I have two spares, after reading about breakages on rally cars (e.g. Duncan and Hugh) I used to take a spare to trackdays but stopped that a while ago.

Yes I know I don't have lots of power, or an LSD, or big slicks etc etc but just backing up Ben's experiences who does have the above! However I do have 260 halfshafts which as has been said before have a 'chunkier' spline. I needed to replace a 240 halfshaft and Pmac had a pair of 260 shafts which he recommended I use.

John - the 'buzz' you get from that turbo kicking-in may necessitate a driveshaft upgrade - I don't know. Perhaps Ben has been lucky. But it might just be worth seeing how you go on with the standard shafts.

 

[johnymd]

I've been driveing around with the standard shafts and the more I drive the more I think why change. I'fs just the though of being stuck somewhere with no drive. I think my best aproach, after listening to all the advice would be to use the car as is and try and get the companion flanges modded (which shouldn't cost much). Then if I do have a problem or when I get round to it I can swap the bits over.

Thanks again.

 

[Rob Gaskin]

I've been driveing around with the standard shafts and the more I drive the more I think why change. I'fs just the though of being stuck somewhere with no drive.

Carry a spare and a 14mm spanner. You know it'll never break if you do that

 

[zedhead260]

Join the RAC.

 

[rallymanDP]

Ben - in the 70's the Engineers designed the 240Z with Driveshafts which were made to a budget price and which would cope with around 140bhp.

Nowadays we are putting nearly twice that amount through parts which are 35 years old.

The fact that every one of us who has rallied a 240Z and has broken them should determine that they will not reliably handle that sort of power - and my point here is about reliability.

Yes, you may get away with the standard items in the short term - but why live with something that you know can be guaranteed to fail in the not too distant future - especially when there is a simple solution available ?

 

[johnymd]

Been to see a guy called Ted this afternoon. Took over the bits and explained what I wanted done and he's quoted me £20 to do the machineing. This guy's been used by Z club members to modify S13 boxes and he seams to know what he's doing. I now need to work out the finished size for each side and get back to him. I'll take some pics and get the some drawing done in case anyone else wants any (can't garrantee the same price though).

Even got a contact number for the next bit of land so I can start another new build so quite a successful Friday. Haven't broke that to the wife yet!

 

[Rob Gaskin]

Duncan yes I fully understand and I was at Silverstone the day you broke a shaft and it spoilt your day on the Roger Clark Super Special stage event. I am right in saying it broke on the jump (track cross-over)?

Hugh broke one on the first stage of the Isle of Man rally and it basically cost him about £2k in rally costs.

I think someone has broken a shaft at Santa Pod too.

What shafts did Harpel use on the Safari 240Z anybody know?

I was just pointing out that the standard shaft will take quite a lot of stick. However if I was competing I'd probably upgrade too.

 

[datsun dave]

I have broken two drive shafts a gearbox and a diff at Santa Pod "the good old days"

And not all at the same time and i was lucky that Keven Irons used to live up the road from the Pod and would bring out replacemen parts for me and Mark Rayner to fit so i could get home.

 

[samuri-240]

Is there any visual way of telling 240 &260 driveshafts apart without splitting them ?

 

[Rob Gaskin]

Is there any visual way of telling 240 &260 driveshafts apart without splitting them ?

Do you mean driveshafts or halfshafts (the hub end)?

If halfshafts then yes, they have a couple of 'lumps' on the hub centre, visible in centre of the wheel.

Dave, thought it was you!

 

[Nigel Brook]

Been trying to find the definitive length of the companion flanges for fitting the CV shafts for some time with limited sucess. One of the problems is the "top hat" grease seal on the end of the shafts which also acts as a stop for an internal spring pushing the shaft back to its normal position. If the companion flange is reduced too much then the seal cannot be fitted. I note that the MSA adaptors increase the available shaft travel by around 2". Has anyone fitted the MSA flanges and have they checked for binding ? I'm assuming the MSA system utilises the seal.

 

[Rob Gaskin]

Been trying to find the definitive length of the companion flanges for fitting the CV shafts for some time with limited sucess. One of the problems is the "top hat" grease seal on the end of the shafts which also acts as a stop for an internal spring pushing the shaft back to its normal position. If the companion flange is reduced too much then the seal cannot be fitted. I note that the MSA adaptors increase the available shaft travel by around 2". Has anyone fitted the MSA flanges and have they checked for binding ? I'm assuming the MSA system utilises the seal.

A few pictures would be good here Nigel. I haven't any CV shafts to look at.

 

[johnymd]

been looking at the difference between 240z and 280zx driveshafts when compressed. The 280zx will compress another 15mm, ie: be 15mm shorter when fully compressed. I had forgotten about room for the center bit that sticks out on the 280zx. I know these have been modded before so you would think someone would have alll the info required for the optimal length. I'll have another look today but hopefully someone who has done the conversion will chip in.

 

[Nigel Brook]

been looking at the difference between 240z and 280zx driveshafts when compressed. The 280zx will compress another 15mm, ie: be 15mm shorter when fully compressed. I had forgotten about room for the center bit that sticks out on the 280zx. I know these have been modded before so you would think someone would have alll the info required for the optimal length. I'll have another look today but hopefully someone who has done the conversion will chip in.

Trouble is 15mm is not enough when fitted to the R200 diff, then there is the "top hat" as well.

 

[johnymd]

Trouble is 15mm is not enough when fitted to the R200 diff,

Not quite sue what you mean by this. I'm currently running a R200 with 240z driveshafts and I don't think its binding. The 280zx shafts are shorter so let chance of binding with the same length companion flange. Are you saying I need to make it a lot longer to allow for the top hat? What if I remake to top hat shorter and grind a bit off the end of the shaft?

 

[Nigel Brook]

To keep things simple? my preferred solution is to use a modified zx companion flange to accomodate the top hat and allow enough movement in the shaft. This is why I'm looking for the modified length of the zx companion flange which is way too long in its standard form. You are presumably using the standard flange which is already shorter but won't facilitate the top hat of the zx shaft. I don't think you will need to grind the shaft but you will need some way of accomodating the top hat. The MSA kit seems the way to go for you.

 

[johnymd]

Just had a thought. Modern motorsport make an adaptor for use with CV's on a 240z. This is basically a modified companion flange (as most of you probable know). I know this is the correct length so all I need to do is find someone with these adaptors and get them to take some measurements. Then I just have to make my adaptors the same length.

So who can measure one for me?

 

[johnymd]

Nigel. I remember reading about modifying the 280zx companion to use on a 240. From what I recall it was just a case of altering the dust shield. I'll have to have another look for the article. I'm not sure if the spline count is 25 or 27 though. 240 is 25 but I want to use 260 axle which is 27 so this may not be an option.