Tutorial: Holden diff fitted to a 240Z

[PeterAllen]

For a start I can’t give even an estimate on what it would cost all up to do this install. There is a lot of metal fabrication and if you were to pay a commercial workshop it could be expensive. I am fortunate to be able to do most of the shaping, forming and welding myself and I have a brother-in-law who has a lathe and each turned component cost me a bottle of Jack Daniels.

The good news is there was no modifications required to the car itself… everything is bolt-on.



The LSD diff I used (3.46) came fitted to the wrecked 2005 VZ SS Ute I purchased for its LS1 motor and T56 gearbox I have also installed. These diffs have been around for about a decade so they are cheap and plentiful. I actually bought a taller one (3.07) off eBay for $150.

In attaching to the two rear moustache bar mounts I was fortunate to buy just the bushing housings from the mob which make the moustache bars for Arizona Z but they’ve stopped selling now. Don’t ask Dave for them as he will only sell the complete bar set-up. I suspect you could also cut these off an existing bar and weld or bolts them to your own moustache bar. Remember that Datsun moustache bars are made from spring steel so bolting would be preferable to welding.

For the moustache bar I used 50mm x 25mm steel tube and I welded in sleeves, to prevent crushing, for the four bolts holding the mount housings on each end and for the two bolts attaching the main rear diff mount plate.



The picture of the rear diff mount plate probably explains it more than any words I can string together. It is triangulated by being secured with three large bolts which came with its original install into a Holden.



I probably went through a dozen designs and prototypes for the front mount before settling on what I have. The problem was to use the existing mounting points (for the Datsun diff tie-down strap) which were well forward of the front mounting points on the Holden diff. We turned up our own red polyurethane bushes (a bottle of Jack Daniels) which was a PITA so I would see if a suitable sized commercially available bushing was available in future. Again a picture is worth a thousand words.



One difficulty with the front mount is the Holden rubber tailshaft coupling I’m using in lieu of a standard universal joint rotates close to the new mount and countersunk bolts are required. Unfortunately nobody manufactures these 10mm (or is 12mm?) with a fine thread. I bought longer bolts with some plain shank and cut a fine thread on the lathe and then cut the bolt to length, i.e. another bottle Jack Daniels!





To use the Holden CVs a coupling was machined to mate to the Datsun stub axle coupling. Yet another bottle of Jack! Again pictures explain it all.

 

 

The Holden CV is a universal type best known as a Porsche 930 CV. They are used extensively in off road buggies and this has the added advantage of there being drive shafts (USA =axles) available cheaply. Holdens are usually fitted with different CV, inners and outers. One is a fixed type (27 splines) and one is a 'plunge' type (28 splines). Use only the plunge type CVs so make sure you get shafts/axles with 28 splined ends, not the 33. Unfortunately none are the exact length – 350mm – so you need to buy a pair of 15 5/8” shafts and cut them down to length. You then need to machine two circlip grooves into each splined sections to secure the CVs. i.e. yet another bottle of Jack!









The overall set-up.

 

 

Because this whole project is a hobby to me the process was undertaken incrementally over quite a long time period – I’m enjoying the journey! However, now that I have written this I can see that it’s probably quite daunting to someone without cheap access to machining.

I do have drawings and templates available to anyone who is GENUINELY going to go ahead with an install.

Edited November 20, 2015 by PeterAllen

[George]

Nice write up Peter.

 

Your brother-in-law must have a lot of JD by now!

[KatoKid]

Love your work Peter!

[620Z]

Looks great Peter.

[Dan260Z]

Amazing effort there Peter - very impressive! 

 

I'm in the process of a CV conversion (in addition to adding an S15 Helical to my R200) which will use a commodore outer CV joint - could I trouble you for a 3D CAD file (if you have one) of the adapter you machined up to go between the CV's and the 4-bolt 240z companion flange??

 

http://www.viczcar.com/forum/index.php/topic,5033.30.html

 

There seems to be a few porsche 930<-->S30 companion flange adapters on the market, but they all appear very thick and I'll need a very thin one (whilst still allowing for joint cage protrusion, etc) so I was hoping to modify an existing design to be thinner and have it machined up

[red76z]

This I My Diff Set up.

Same as above but all mounted on to the zed frame work and bolts onto the original mount points using original mustash bar.

cost me $2500 in fabrication alone.

[600Z]

That looks like a very nice job red76z. Are your half shafts cv inner and uni outer?

[red76z]

That is correct 600z

This way I didn't have to modify the zed hubs.

 

[600Z]

Ah very true otherwise you would need adapters similar to the ones I have with the wolfcreek axles I have and just more to go wrong I think.

 

That setup you have is very neat.

[260DET]

Any chance that you can reinstate your pics Peter?

[PeterAllen]

The problem is at your end - so to speak.

 

Photobucket have tried to block free 3rd party posting but Google have addressed the problem by creating 'extensions'.

 

This should do the trick if you're using Google Chrome. If you're using Firefox or something else you might be able to mimic these instructions.

 

Click on the 3 vertical dots in the top right hand corner
Click on 'Settings'
Click on 'Advanced'
Click on 'Accessibility'
Type in "photobucket" to the search box in the top left hand corner
Click on 'Photobucket fixer'
You should see 3 extensions appear - Select each of them.
Restart Google and you should see images on all forums.

I think Photobucket would stand a better chance taking on Kim Jong-un than Google!

 

Possibly Gary could make some sort of tacky sticky about this Photobucket issue?

Edited October 25, 2017 by PeterAllen

[Cozza]

You crack me up Peter ?

[George]

The problem is at your end - so to speak.

 

Photobucket have tried to block free 3rd party posting but Google have addressed the problem by creating 'extensions'.

 

This should do the trick if you're using Google Chrome. If you're using Firefox or something else you might be able to mimic these instructions.

 

Click on the 3 vertical dots in the top right hand corner

Click on 'Settings'

Click on 'Advanced'

Click on 'Accessibility'

Type in "photobucket" to the search box in the top left hand corner

Click on 'Photobucket fixer'

You should see 3 extensions appear - Select each of them.

Restart Google and you should see images on all forums.

 

I think Photobucket would stand a better chance taking on Kim Jong-un than Google!

 

Possibly Gary could make some sort of tacky sticky about this Photobucket issue?

 

You have single-handedly fixed the interwebs. Thanks.

[aussie240z]

great article and fix for the photobucket issue. Just an aside, you can do a CTRL F5 on the tab that is open if you dont want to restart the whole browser. I had about 20 tabs open and didn't want to lose all of them, so tried the standard clear cache ctrl f5 to good effect

[Howdy]

Nice work Peter, I wish I had have seen this earlier when I replaced my CVs, never realized Holden were the same as 930s. Now I'll commit that to memory for next time then probably forget damit.