VN Diff Shortening

Includes clutch, transmission, propeller shaft,
universal joints, differential and rear axle.

Moderators: reidy, Blacky

fbidek
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Re: VN Diff Shortening

Post by fbidek »

The P refers to positive.
The standard Commodore VN wheels are a 43mm positive offset - they are stamped 43P on the rim
The VP IRS Commodore wheels are a 26mm positive offset - they are stamped 26P on the rim
The standard early Holden wheels are a 6mm positve offset

A positive offset wheel has the centre mount flange offset towards the outside of the wheel (shallow dish), while a negative offset wheel has the centre mount flange offset towards the inside of the wheel (deep dish)

The other way of identifing the differneces in wheels is backspace, but the offset from centre method seems to be more the norm these days.

Hope this answers the question if not yell out.
Ben
FATBOY
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Re: VN Diff Shortening

Post by FATBOY »

yep understand how you worked it out .Most wheel manufactures work from the mounting face (backset) thats why i was confused
regards fatboy
fbidek
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Re: VN Diff Shortening

Post by fbidek »

Got the welder fired up and finished the shortening of the diff assembly.
Next to fit the leaf spring saddles.

Image

Unfortunately I take a while to plan but when I get to doing it I am too impatient to stop and take pictures.
Here is what was left over after the sparks flew.
2 cutoffs from the diff and 2 ends of the axles after being chopped.

Image
steved57
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Re: VN Diff Shortening

Post by steved57 »

Hi Ben

Where are you going to get the VP 26P wheels from? Given that the IRS was only fitted to upspec VP models wouldn't the 26P wheels be as rare as the proverbial rocking horse droppings, particularly in steel (cop cars?)? I'd be very interested to know if these are available as they'd get me out of a jam too.

Cheers, Steve
fbidek
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Re: VN Diff Shortening

Post by fbidek »

I was very surprised how easy they were to get as I thought I would have a hard time in getting them, but went to the local Commodore wreckers and they had plenty.
They were also used on the VQ Statesman (series 1 with wheel covers not alloys). I picked up 4 of the 15x6 26P's for $20 each.
My fall back plan was to get the 43P's reset.

I think the 26P's will better suit the front HR front end.

I am looking at some different hub caps now.
Hope to have some details soon.
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Harv
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Re: VN Diff Shortening

Post by Harv »

Thanks Ben... 17mm less offset on a Commodore rim reminds me of the problem I still have with a HR frontend:
http://www.fbekholden.com/forum/viewtop ... dore+wheel

Now to find a VP or VQ statey and trial fit..... :D
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.
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Harv
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Re: VN Diff Shortening

Post by Harv »

Hmmm... some more internet hunting over on the Just Commodores forum:
VB - VL = 43+
VN = 43+
VP = 43 + optional offset is 42 + or 31 + for V8 Exec sedan
VP Berlina = 26 +
VP ABS IRS = 26 +
VR Executive = 43 +
VR Executive wagon = 40 + or 43 +
VR Berlina sedan = 43 +
VR ABS IRS = 26 +VS Exec wagon = 43 + or 37 +
VT Acclaim V6 = 26 + all other VTs are 43 +
VX all models are 43 +
VY Exec V6 = 43 +
VY SC V6 = 41 +
VY Exec wagon = 43 + or 41 + for the 5.7 L
VY2 = 43 +
VY2 SC V6 = 41 +
VZ Exec = 43 +
VZ Acclaim = 41 +

This may explain why they the 26P's are cheap and plentiful - they were on a few cars (VP Berlina, VP and VR with ABS/IRS, VT Aclaim V6 and VQ Statey Series 1).
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.
sgo
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Re: VN Diff Shortening

Post by sgo »

Just wondering if any of these changes put the pinion in the centre of the rear end, or is clearance with the tail-shaft tunnel not an issue?
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michaeljohn1234m
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Re: VN Diff Shortening

Post by michaeljohn1234m »

fbidek wrote:Got the welder fired up and finished the shortening of the diff assembly.
Next to fit the leaf spring saddles.

Image

Unfortunately I take a while to plan but when I get to doing it I am too impatient to stop and take pictures.
Here is what was left over after the sparks flew.
2 cutoffs from the diff and 2 ends of the axles after being chopped.

Image
fbidek I'm new to this form and just read your thread just what i was looking for, as I'm about to get Pat gardner(v6 conversions) to do mine,but this thread has got me thinking of doing it myself, so how did it finally go in the car (did it work) well and can some tell me if a VS diff is the same width as the VN so i can use the diagrams
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michaeljohn1234m
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Re: VN Diff Shortening

Post by michaeljohn1234m »

fbidek wrote:Image
can you tell me what diameter tube your using to reinforce the axle
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michaeljohn1234m
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Re: VN Diff Shortening

Post by michaeljohn1234m »

do you use the ek u bolts or commadore u bolts, as i don't have my old ones to check if they fit http://www.ebay.com.au/itm/120840157601 ... 1438.l2649
DOLLER
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Re: VN Diff Shortening

Post by DOLLER »

Use HQ Type plate and U bolts :wink: Twice as strong
Run what ya brung and hope it's enough
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michaeljohn1234m
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Re: VN Diff Shortening

Post by michaeljohn1234m »

has anyone had or heard about these axels
http://www.ebay.com.au/itm/320965959476 ... 1438.l2649
a good price and can cut to length
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ekdave1962
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Re: VN Diff Shortening

Post by ekdave1962 »

hi guys i did a similar think on my ek .. i find the under hard acceleration the rearend squats causing the tail shaft to hit floor .. it has almost sliced through so i need a fix ..
was thinking of coil over type shockers to prevent the squat ..
any suggestions of what shockers will fit or any other solutions ?'''

thanks David
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Errol62
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Re: VN Diff Shortening

Post by Errol62 »

Channel your tail shaft tunnel?
getting my FB ute on the road
EK van on rotisserie
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