S13 / S14 gearbox - propshaft length

[SeanDezart]

Please can anyone tell me the correct overall length (including both CV ends - see photos) to order ?

The prop in the photos is slightly shorter to accomodate an engine further back in the engine bay so if someone can tell me the correct length for a standard-placed engine, that's be great - thanks.

 

[Huw]

Hiya Sean.
Is the engine and box in the car at the moment? I ask because when I measured the prop for my conversion I took the measurements from the wrong points. It’s an easy thing to do apparently.

The company I used in Bristol put me right by lending me the front part of a propshaft (the bit that goes into the gearbox) and instructions to "stick it into the box as far as it will go and measure from the middle of the joint to the diff flange". For my 2 seater 280ZX with a S14a box, that length was 576mm. The prop needed 52mm taking out of it to fit the new box.

Huw

 

[AliK]

Sean, not having done it myself but made plans to, I’ve read that the stock size is 22.5” between yoke centres.

Dumb question de jour: Doesn’t it depend on the car it’s going into? I thought the R180 diff in a 240 was further forward but I don’t know if the diff is shorter than the R200 in my 260 and the prop shafts are the same size between models?


This is a great read btw ...


http://zhome.com/ZCMnL/tech/240SX5spd/transmission4.htm

 

[atomman]

I've got a spare one in the garage , will measure it later for you

when I did mine i'm sure the 22.5" in the above post was to long

 

[johnymd]

I think the top picture is the one from Dean's car so that will be the correct length as his engine and box are in the factory position. There is a bit of wiggle room as you want to be able to push the prop in and out of the slip joint by at least an inch.

 

[Woody928]

Sean you'll need to measure your own car, in my experience there isn't a one size fits all standard length prop with this conversion (even if the slip yoke buys you some fudging room).

For example being an early production car my diff is situated further forward that a later production car, you would need totally different size prop shafts for respective cars. That's before you get into different gearboxes and engine mounting as well. I'm also talking R180's here, no idea if the R200 changes anything again.

I'd suggest measuring yours when possible and having one made to your specific needs, I ended up having a custom and uprated one made by a local shop who did a fantastic job.

 

[Rob Gaskin]

Swapping to an R200 doesn't normally necessitate a propshaft change. The tight bit is one of the driveshafts.

 

[SeanDezart]

For info guys, I don't have my car here and I was hoping to have this produced andf sent to the UK address where my car is to collect at the same time - mine is an R180 diff and the engine is in the stock position : Woody why should each car be radically different ?

For my 2 seater 280ZX with a S14a box, that length was 576mm. The prop needed 52mm taking out of it to fit the new box.

Thanks Huw but is the 240Z the same as the 280ZX SWB ?

Thanks John, yes, it is Deans' but his engine is not in the factory position (so he says) - it's been moved as far back as possible !

 

[atomman]

Just taken some photos of the one I used to mock up and gave to the shop to make my up-rated one and its near as the same as the one in your first post ?

27.5" or 20.5" between yoke centres

my engine is on stock mounts in the stock position with diff in the stock position

 

[johnymd]

Here is my take on “every car is different”. If you need a standard prop for a standard 240z you just buy a factory prop and don’t get it modified to fit your specific car. Yes, you do have tolerances in engine mount bolts of which there are 3 so you can end up with the engine/box a max of 6mm either way but the prop has a slip joint to allow for this. The s13/14 box is a specific length different from the factory 240 prop which can’t change so in theory all conversion props can be calculated and will be the same length. You can get away with up to an inch shorter and maybe a 1/2 inch longer and it will still fit ok.

 

[SeanDezart]

27.5" or 20.5" between yoke centres
my engine is on stock mounts in the stock position with diff in the stock position

Thanks very much - it looks to be 703mm in overall length compared to Deans' of 693 which maybe his moving backwards the engine by 10mm - checking with him now.

Thx John - have you done an S13/14 conversion - can you remember the overall length ? Ideally, I don't want any or at worst the minimum play.

Cheers.

 

[johnymd]

I have this conversion on my silver car and I took measurements from the car. IMO it may be a little short though. Next time I will do it as Nissan originally designed so take advantage of their calculation for weight transfer under all possible conditions. They will have been very careful to make sure the length was optimal. So I will take the factory prop length and adjust that by the difference in gearbox lengths between bellhousing face and rear seal. This should ensure that just the right amount of allowance is made for engine/gearbox and diff movement under acceleration/braking is allowed for.

I think I still have a spare new prop (if I didn’t give them all to Dean) that I can measure just for reference. I’ll try to check today.

There is zero vibration in my silver car by the way.

 

[johnymd]

So, I did a little digging and have some more info to add.

1. S13/14 gearbox is 50mm longer than a 240z box.
2. Early 240z prop is 35mm shorter than a later prop.
3. The splined part of the prop is designed to still have 38mm of end movement before it bottoms out in the gearbox.

From this we can come to some conclusions.

1. If you shorten a standard late 240z prop by 50mm and remove its dust shield it will be the correct length for s14.
2. An early 240z prop will fit by just removing the dust shield due to the diff being further forward in the car.
3. The prop has plenty of engagement to come out a little more and you can probably use some of the 38mm space in the gearbox.

 

[toopy]

So, I did a little digging and have some more info to add.

1. S13/14 gearbox is 50mm longer than a 240z box.
2. Early 240z prop is 35mm shorter than a later prop.
3. The splined part of the prop is designed to still have 38mm of end movement before it bottoms out in the gearbox.

From this we can come to some conclusions.

1. If you shorten a standard late 240z prop by 50mm and remove its dust shield it will be the correct length for s14.
2. An early 240z prop will fit by just removing the dust shield due to the diff being further forward in the car.
3. The prop has plenty of engagement to come out a little more and you can probably use some of the 38mm space in the gearbox.

Great info John, that should be a sticky somewhere

 

[240L31]

So, I did a little digging and have some more info to add.



1. If you shorten a standard late 240z prop by 50mm and remove its dust shield it will be the correct length for s14.
2. An early 240z prop will fit by just removing the dust shield due to the diff being further forward in the car.

You are right, the Series 1 prop shaft is around 35mm shorter than the series 2. It will fit the S13 conversion, I went this route last year. However, it is still slightly to long! It is difficult to install plus it breaks the gearbox output shaft seal after some time. This is due to the output shaft seal sitting at the very end of the slip yoke (where the radius of the yoke starts).

I had my series 1 shaft shortened by another 10mm, now it fits perfectly. This equals a series 2 shaft shortend by 45mm.

My car: 8/71 240Z, S13 gearbox, Subaru R180, late (stock) mustache bar.

 

[Woody928]

For info guys, I don't have my car here and I was hoping to have this produced andf sent to the UK address where my car is to collect at the same time - mine is an R180 diff and the engine is in the stock position : Woody why should each car be radically different ?

I'm guessing no one in the UK can measure it for you then? It shouldn't be radically different (in theory), however as already mentioned depending on the year of the car then the diff will be positioned differently.

Ideally, I don't want any or at worst the minimum play.

Only one way to ensure this imo, we got it wrong the first time on my car and had to go back later to do it again...

From this we can come to some conclusions.

1. If you shorten a standard late 240z prop by 50mm and remove its dust shield it will be the correct length for s14.
2. An early 240z prop will fit by just removing the dust shield due to the diff being further forward in the car.
3. The prop has plenty of engagement to come out a little more and you can probably use some of the 38mm space in the gearbox.

Re point two, I'm pretty sure my factory prop (which is from an early production car) did not have a slip yoke setup due to its production year. We therefore couldn't use it for my S14 conversion.

 

[johnymd]

There are certain early models that have the flange at both ends and the slip joint in the middle as you say. These can obviously not be used. One of my UK cars has this setup and it’s not an early car.

 

[richiep]

There are certain early models that have the flange at both ends and the slip joint in the middle as you say. These can obviously not be used. One of my UK cars has this setup and it’s not an early car.

My red Z was like this - early 71 car, early two-piece prop, but with 4-bolt flanges at both ends. The 5-speed was a 71B box of a type seen on other models in Japan rather than a Z-specific box. When doing the S14a box swap, I simply used a later Z prop. However, because the car is an earlier one (i.e. pre-early 72) the diff is 35mm further forward. This obviously must be accounted for when shortening the prop, i.e. an 85mm chop, if you aren't planning to move the diff further back to its later position.

 

[SeanDezart]

So, I did a little digging and have some more info to add.

1. S13/14 gearbox is 50mm longer than a 240z box.
2. Early 240z prop is 35mm shorter than a later prop.
3. The splined part of the prop is designed to still have 38mm of end movement before it bottoms out in the gearbox.

From this we can come to some conclusions.

1. If you shorten a standard late 240z prop by 50mm and remove its dust shield it will be the correct length for s14.
2. An early 240z prop will fit by just removing the dust shield due to the diff being further forward in the car.
3. The prop has plenty of engagement to come out a little more and you can probably use some of the 38mm space in the gearbox.

John, can you complete the dimensions by sharing with us the lengths of the two original 240Z type propshafts please ?

Your info is good but if one doesn't want to shorten a stock prop and one doesn't have one loose to hand - it doesn't help ordering a new one.

 

[johnymd]

Yes Sean. I don’t have the dimension which is why I didn’t include it. I will find out when I’m at the workshop though.