Diff width

[lucky13]

Hi, I know this has probably been done to death.
I am shortening a VR VS diff for my FE sedan and my car is not accessible at this time, could someone give me the measurement of a standard rear wheel space from the outer edge of the chassis rail to the inside edge of the outer lip, thanks.
Any ideas on ideal length for running 15x7 with a 3.5" backspace i have been working on LJ Torana width, but find two different measurements being 1338 and 1370mm wide, wheel mount face to wheel mount face if anyone has used one or cut a diff down any info would be appreciated
Cheers Andrew

[FireKraka]

Hi Lucky I've narrowed a couple of diffs and I found that the best way (unfortunately as you can't access yours)  is to have access to the vehicle, what I do is place the wheels/rims, spaced correctly in the wheel wells and then measure between the centre of the rims where the axles bolt to this will give you correct length you need to make the diff.
Commodore diffs have 1long and 1 short axle so you need to maintain that offset to keep the tail shaft pinion in the centre of the tunnel.
Commodore axles are thicker after the spline and not hardened so can shortened and resplined if you know of a workshop that can do it.
Neil

[Errol62]

Hi Andrew,
I’m in process of installing LJ axle in my FB ute. Face to face just measured 1350mm.


Sent from my iPad using Tapatalk

[Errol62]

My measurement is to the axle flange face and is good to about +/-5mm. The drums will add 4mm I’d say. The edges of my drums protrude a further 7mm either side but the wheels don’t mount on this surface. 1370 measurement is probably to this outer edge. My wheels are 93mm back space or 3 3/4”. 7” rims with 245 tyres they are too close to the inner wheel well but may be ok with mini-tubbing.

FB and FE FC are pretty much identical in the rear tray area, even though the springs were different widths. So should be a fair comparison. Though as Neil says the only true comparison is the vehicle itself.


Sent from my iPad using Tapatalk

[Errol62]

ASI recall my diff and wheels came out of an FE ute. The vendor said they never rubbed and there are no signs on the tyres of rubbing. The aFE hadn’t been tubbed st all do who knows?


Sent from my iPad using Tapatalk

[lucky13]

Thanks guys much appreciated, that's given me more food for thought and some more calculating to do cheers