diff, all you need to know

[Zeussy]

Hey immortality,
If I've got this right...

I am going to be starting a conversion soon, VP into VH, pretty much all the engine/running gear out of the VP, into my old VH... Or had the plans too?

Is the only difference between the diff's the width - as in the track will be 52mm wider = so the wheel will stick out 26mm further each side?? yeah?!

Is there an advantage to put the VP diff in? I was going to just shorten the tailshaft and swap it all.
Or just keep the VH diff? The VH diff is for a trimatic 6, if I used that would the ratio be wrong for the VP aswell?

And do you know if the brakes are the same on the rears, plan to put all the VP booster, calipers etc in with the conversion.
Basically have a complete VP, and going to lift the body/shell off and swap it with a VH...

"WHY" I hear people asking, because the Mrs wants too... lmao,

[immortality]

Hey immortality,
If I've got this right...

I am going to be starting a conversion soon, VP into VH, pretty much all the engine/running gear out of the VP, into my old VH... Or had the plans too?

Is the only difference between the diff's the width - as in the track will be 52mm wider = so the wheel will stick out 26mm further each side?? yeah?!

Is there an advantage to put the VP diff in? I was going to just shorten the tailshaft and swap it all.
Or just keep the VH diff? The VH diff is for a trimatic 6, if I used that would the ratio be wrong for the VP aswell?

And do you know if the brakes are the same on the rears, plan to put all the VP booster, calipers etc in with the conversion.
Basically have a complete VP, and going to lift the body/shell off and swap it with a VH...

"WHY" I hear people asking, because the Mrs wants too... lmao,

firstly, lets look at the diff. the VH SL/E could be optioned with the large salisbury which should be up to the task of a stock V6. not sure what the ratio was. even if it is the smaller sals diff it should be ok. just attach the rear half of the VH drive shaft to the front half of VP drive shaft. yes the BW78 diff from the VP is 52mm wider but it will bolt straight in otherwise. if you do want to go down this path it may be better to source a VL diff as it would be a better fit.

if the VH has a disk brake rear it is basically the same. booster and master cylinder are also the same 15/16" size. basically swap the entire K frame/ front suspension including disks and calipers into the VH.

a V6 will liven up a VH nicely, the same engine KW output as the stock V8

[Zeussy]

firstly, lets look at the diff. the VH SL/E could be optioned with the large salisbury which should be up to the task of a stock V6. not sure what the ratio was. even if it is the smaller sals diff it should be ok. just attach the rear half of the VH drive shaft to the front half of VP drive shaft. yes the BW78 diff from the VP is 52mm wider but it will bolt straight in otherwise. if you do want to go down this path it may be better to source a VL diff as it would be a better fit.

if the VH has a disk brake rear it is basically the same. booster and master cylinder are also the same 15/16" size. basically swap the entire K frame/ front suspension including disks and calipers into the VH.

a V6 will liven up a VH nicely, the same engine KW output as the stock V8

Legend! haha, yeah for sure, a mate had a 5 speed manual, (V6, VH) and it was quite the little weapon. For a measely $250 its by far the cheapest option so far...! Our one will be auto though, still tough enough for a chick! lol.

Yeah, my SLE came with the 4 wheel disc option, so I'll have some spares? Is the handbrake cable the same as well?

How do you tell the difference between the small and large salisbury? I have it just sitting around the side - the SLE has an empty 9 inch sitting under her - no centre just axles and housing. So either way i'll have to put one of the diff's under there?

The tailshaft's rear uni is about 65mm, with roughly 25(ish)mm end caps? And the Diff has the rear plate on it about 26cm wide - not the centre, just the cover plate. Are there any numbers stamped on them?

I'm pretty sure the ratio is 2.78 or something along the lines of? Somebody told me a while ago 'it should be' (when I put the aussie 4sp in it)

Even though I'm a Mechanic (Plant/Earthmoving) I've never really known much about the old gurls!

Cheers mate,

[immortality]

Legend! haha, yeah for sure, a mate had a 5 speed manual, (V6, VH) and it was quite the little weapon. For a measely $250 its by far the cheapest option so far...! Our one will be auto though, still tough enough for a chick! lol.

Yeah, my SLE came with the 4 wheel disc option, so I'll have some spares? Is the handbrake cable the same as well?

How do you tell the difference between the small and large salisbury? I have it just sitting around the side - the SLE has an empty 9 inch sitting under her - no centre just axles and housing. So either way i'll have to put one of the diff's under there?

The tailshaft's rear uni is about 65mm, with roughly 25(ish)mm end caps? And the Diff has the rear plate on it about 26cm wide - not the centre, just the cover plate. Are there any numbers stamped on them?

I'm pretty sure the ratio is 2.78 or something along the lines of? Somebody told me a while ago 'it should be' (when I put the aussie 4sp in it)

Even though I'm a Mechanic (Plant/Earthmoving) I've never really known much about the old gurls!

Cheers mate,

well, the 9" diff is worth a bit. could pay for the a lot of the conversion bits

the large sals diff has a egg shaped cover on the back of the diff. the small sals was round. also the large sals uses a 10bolt center. if you pull the diff cover off the diff ratio will be stamped somewhere around the circumference of the crown wheel.

there is a thread stickied at the top of the VB-VK section dedicated to doing V6 conversions. should have all the info you might need

[Zeussy]

well, the 9" diff is worth a bit. could pay for the a lot of the conversion bits

the large sals diff has a egg shaped cover on the back of the diff. the small sals was round. also the large sals uses a 10bolt center. if you pull the diff cover off the diff ratio will be stamped somewhere around the circumference of the crown wheel.

there is a thread stickied at the top of the VB-VK section dedicated to doing V6 conversions. should have all the info you might need

It could pretty much pay for it, OR it could pay for some paint for my VY!!! lmao... Finally!

Well, the cover looks to be closer to round, than egg shaped, so thats a bummer. Might try find a decent/cheap VL diff, does it have to be V8? And what ratio would be preferable, in your opinion?

Theres still the option of the VP diff as a fall back plan, might even try that first, then if the tyres stick out too much worry about it then?
In the 'VB/VK V6 Conversions' thread they say something along the lines that the VR/VS is where the models get wider, and the front of a VN/VP will be the same width as the VB/VK? Is the rear wider than the front? lol.
Hmm, something to ponder anyway?!!

Over the last few days I have been doing a bit of reading! Mainly the V6 conversion threads, then deviating onto other topics, then luckily came accross this great thread - Good write up btw! lots of info in it. LOL.



I swear this website is full of potentially verrry valuable information, High five for all involved!!

[immortality]

It could pretty much pay for it, OR it could pay for some paint for my VY!!! lmao... Finally!

Well, the cover looks to be closer to round, than egg shaped, so thats a bummer. Might try find a decent/cheap VL diff, does it have to be V8? And what ratio would be preferable, in your opinion?

Theres still the option of the VP diff as a fall back plan, might even try that first, then if the tyres stick out too much worry about it then?
In the 'VB/VK V6 Conversions' thread they say something along the lines that the VR/VS is where the models get wider, and the front of a VN/VP will be the same width as the VB/VK? Is the rear wider than the front? lol.
Hmm, something to ponder anyway?!!

Over the last few days I have been doing a bit of reading! Mainly the V6 conversion threads, then deviating onto other topics, then luckily came accross this great thread - Good write up btw! lots of info in it. LOL.



I swear this website is full of potentially verrry valuable information, High five for all involved!!

you can use any VL diff, although all the V8 ones were 4spider centers using 28spline axles and had the 3.08 ratio.

the 6cyl VL had 3.45 gears but only used a 2 spider 25 spline center. you could upgrade to a 4 spider center from any other BW78 diff but the issue will be getting axles that are the correct length. you could use a VLT diff but people seem to think these are gold plated and charge accordingly.

yes, the fronts of the VN/VP are the same. the width of the diff did change. thats why a VN with stock 14 or 15 inch wheels looks puss because the body looks way to wide. you could try the VN diff, as long as you don't chuck 17x8" rims on it, it might not be to bad.

no point keeping all the info to ones self. might as well share it. i've learned plenty from people on this site so it's only proper to return the favour

[Zeussy]

Haha, yeah I've noticed the VN's wheelbase - width looks way too narrow for the cars body..!

Probly eventually will be getting rims, its just sitting on the SLE rims, they're polished up shiney! I had the 20's on it before I took it off the road.
So probly should do it right the first time then. (not to put 20's back on it, but most likely something a bit more comfortable)

So preferably a VL V8 diff, and if we can't get a complete one, (which we should be able to, but just so I understand correctly) any VL diff, with the VP Centre, (the one in the doner car) and VL V8 axles - is that the right combo? lol,

Sorry for all the questions, I really appreciate all the help.

I always try to help others where I can too. I have the same attitude, I've learnt heaps from here, so I'll try to help someone back..

What ever else I end up learning from all this I will be sharing with the rest of the forum! Either in the 'VB/VK V6 Conversion' thread or this one, or both lol, and my ride thread.

[immortality]

a complete VL V8 diff would be the go as it's already a 4 spider 28spline unit. if you can't find one of those a a 6cyl VL diff with your VP center and you would need to find some 28spline shafts to suit

check this thread for a pic of a large salisbury diff. your top mounts will be different though

[alexg]

Hey I have Datsun 1600 engine that I'm putting into a bluebird TRX, and I'm after an LSD for a Banjo differential, could someone recommend a fairly cheap way of doing this?

[kenhouse]

I have a vs v6 LSD 3.08:1 ..would the centre fit into a vl diff housing using vl axels ?

[Kernal]

If i put a VX SS diff into a vt s1 v6 do i have to change CV's and hubs? to vx ss ones??

[old mate]

just a quick question. is the only 'diff'erence (lol) between the v6 and v8 diffs in a vs ute the shot peened gears, or are the axles and other bits different?

[immortality]

just a quick question. is the only 'diff'erence (lol) between the v6 and v8 diffs in a vs ute the shot peened gears, or are the axles and other bits different?

yep. just shot peened gears. unless it has the "performance diff" tag. which should mean it's optioned with the LSD diff

[old mate]

i've got the high peformance tag but its a single spinner. maybe all the utes had shot peened gears??

[5 speed VR]

If there is a tag saying "use LSD oil" its an LSD, but if its got "use high performance oil" its just a V8 diff

[fnlow1]

Diff upgrades

However it is possible to fit the entire IRS setup from a late model commodore (VTs2,VX,VY) into a earlier model IRS comodore but you also need to use the drive shafts and hubs from the donor car (STEALTHY has done this in his VP international)

if there is anyhting i've missed or you believe is incorrect please add it beneath and i'll update this post as info becomes available

I reckon you will find that the early model and late model IRS diffs have different flanges where they bolt to the tail-shaft- so they are not a straight swap. Late model cradle wont bolt up to early models. Trailing arms are interchangeable- keep in mind hubs differ depending on model also track link adjustment (or whatever its called) wasn't introduced to VX Series II. Sorry if this has all been discussed earlier.

[VK_3800]

Some more info on widths of VK 1/2 and VL Borg Warner housings:
vl axles into vk diff

According to my measurements the two are identical in width, but the VK 1/2 centre is somewhere in the region of 30mm further offset to the right when compared to VL. This means the short and long axles are 30mm longer and shorter respectively.

Not sure where the quoted 12mm width difference figure came from; approximately 6mm could be accounted for in the difference between drum and disk brakes. It has also been suggested that the Salisbury could be slightly different, I don't have any here to measure to check this.

[VzVzVz]

Everything you need to know but pulling it out. :P

[mrtdk59]

Just want to see if I got this right.
I own a VN V6 series II with the standard BW single spinner diff - ratio is 3.08
So this diff has 4 pinions carriers with 28 spline axles.

Can this diff be modified to LSD setup, as this is a stronger diff all round.
I'm told my current diff will not handle my intended mods of a heavily modified blown V6 with 6 speed manual from a later model commy.
As I am in Brisbane, is there a reputable person/workshop who can modify my diff if needed.
Thanks for your time

[Pub247]

Just want to see if I got this right.
I own a VN V6 series II with the standard BW single spinner diff - ratio is 3.08
So this diff has 4 pinions carriers with 28 spline axles.

Can this diff be modified to LSD setup, as this is a stronger diff all round.
I'm told my current diff will not handle my intended mods of a heavily modified blown V6 with 6 speed manual from a later model commy.
As I am in Brisbane, is there a reputable person/workshop who can modify my diff if needed.
Thanks for your time

For the First Part the answer is yes.

Secondly the Borgwarner78 series diff is exactly the same as the lsd version besides the the centre Being an lsd instead of an open wheel.


So you just need a LSD center put in and away you go. A Rebuilt LSD should handle a blown V6 easy. There are few other options to look at including spools and lokka diffs. Personally id stick with LSD.

[immortality]

there is a guy on SC who uses a shimmed BW 78 LSD diff in a 9 second VL V8 turbo. nuff said about how strong they are when they are built properly

[Drawnnite]

so ive asked this elsewhere but think it would be more related to this thread.

ok so i have a VN V8 LSD all recoed etc.
i have read the VN Wagon diff is the same as the VS ute.

however it regards the Bump Stops.

would any modifications have to be made so it will fit or would it not matter?
for eg is there any plates different or none at all?

Thanks in advance

EDIT:
i think i answered my own question by looking properly, but i may be wrong, any info would be awesome

[Sophie92]

wondering if its worth swapping my stock vt diff ratio's for the r31 4.11. my vt is just a daily but looking for more accelleration out of the gears more then speed. being that i think the v6 ecotech in the vt is to laggy in 2nd and 3rd. all opinions appreciated.

~Sophie

[Drawnnite]

wondering if its worth swapping my stock vt diff ratio's for the r31 4.11. my vt is just a daily but looking for more accelleration out of the gears more then speed. being that i think the v6 ecotech in the vt is to laggy in 2nd and 3rd. all opinions appreciated.

~Sophie

4.11s are pretty high for a daily.
if you dont drive it much for work then maybe.
otherwise have you thought about 3.45's or 3.7's
just so you dont completely kill the fuel economy =P

[GTP 85]

first of all Sophie you have to have a squiz under your car and check which diff is in it. There will be a tag on the driver size of the diff with the diff ratio printed on it.

If you have 3.07 then you will need to find diff gears from a later model commodore

If you have 3.08 then you can use gears from a skyline.

What ratio to choose is personal preference really. Horses for courses if you wish... A car that is purely city driven= Go skyline 3.89's (3.91's if you have the 3.07 diff). For a car that gets driven over 80km/h regularly i'd lean more toward 3.45 (3.46 if you have the 3.07 diff)

If i didnt have to tow cars on the highway with my daily then i'd go 3.91's in a heart beat