29 replies to this topic

[76lxhatch]

Salisbury diffs have equal length axles, no long and short like the later Borg Warners.

I can't tell you any lengths off the top of my head but I have a feeling the Commodore is around 100mm wider overall (remember the wheels are different offset) so it'd be completely wrong to make them work. Maybe you could grab some of the 28 spline ones and shorten them, they'd have more meat to do so?

I gather you are talking about just changing the axles rather than the whole diff? The latter would make more sense as the wheels wouldn't sit so far inboard but a lot of expense for not much gain.

[Uncle Chop Chop]

VK series 1 diff is about 65mm wider than the LX diff. WB 6 cyl axles can't be shortened as GMH only hardened them in the spline area. HQ - WB 1 tonner axles CAN be shortened, but good luck finding any.

[76lxhatch]

Yes resplining will likely be a problem with Commodore small Salisbury axles.

Yes 28 spline axles are bigger and thicker, but I mentioned them because of the above, you may have enough meat to shorten and re-spline these to 23 spline. One tonner axles are the beefiest of the lot but again require shortening and machining to suit (plus they have HQ stud pattern).

I understand what you're saying with the VP wheels being a different offset to most Commodore but I think compared to many aftermarket wheels they probably won't fill the wheel arches that nicely, and again you're stuck with an oddball wheel that is hard to get (although admittedly there is a bit more in these offsets if you look at BMW). Personally if I was going to spend money on it I'd be doing something that gives me a much wider range of wheel options.

[TerrA LX]

I really like this idea, plus VP calais mags look like corvette wheels. Let us know how you go with it.

[76lxhatch]

I highly doubt you will have enough spline to get away with cutting them down. I really don't see any cheap and easy way to put Commodore axles in, and its kind of a waste spending too much on that. I have some diffs in my storage shed though, I can go down and measure them tomorrow to get a concrete answer on the widths (I can almost guarantee its not the answer you're looking for though).

If you're going to go Commodore stud pattern you may as well go discs as they're worth nothing these days but work fine.

The original wheel offset is kind of irrelevant, unless you want 5" to 5.5" x 13" wheels that sit way inside the guards...?

If you're not interested in spending money on a diff conversion perhaps it would be better value for money to find some different wheels.

[76lxhatch]

OK, at present the only pre-VN Commodore diff I have is a 4 cylinder one (small Salisbury), these have the 5x108mm stud pattern (basically the same as Torana, and use the same small brakes). Including drums its approximately 1515mm from wheel face to wheel face, I think the six cylinder ones may have been a few mm wider which makes sense with the different brakes?

The Torana diff is approxiately 1445mm wheel face to wheel face including drums. So that makes it at least 70mm difference, 30mm per side, which is way too much to cut the axles down and keep any spline.

I have a couple of UCs with 13x5.5" factory wheels on them, but I'm not 100% sure they are Torana - they kind of look like 4 cylinder Commodore to me but it would be strange if they all are. Maybe they are the same? For some reason I thought the Commodore ones looked different. At any rate they appear to be roughly 4.25" backspace with an overall width of 6.5" to the outside edges (5.5" is inside the beads). This would make them approximately 1" positive offset (25mm, very close to your Commodore wheels surprisingly). This was kind of hard to measure with the mess my shed is in though so take it with a grain of salt - couldn't see any stamped measurements on the wheels (they are probably there but).

The outside edge of the wheels is approximately 2.5" inside the guards on the UC sedan, 3" on the hatch (but the hatch could be bent).

[Uncle Chop Chop]

I know this is not related to the diff but another problem you might have if fitting these 15 inch Commy wheels to the Torana is fouling between the inside edge of the wheel rim and the upper control arm at the upper ball joint.
 
Don't know if you can mock up a measurement of it first but it might be worth doing before you go and convert the front to Commodore stud pattern.
 
A larger diameter wheel should clear fine though.

They clear fine, I've done it before.

[Uncle Chop Chop]

I should clarify that I used 15x6 steel rims with stock offset (+43) and Commodore front discs.

[76lxhatch]

According to this book I have the 4 cyl Commy VC model has a rear track of 1445 and the V8 1420. Unfortunately it doesn't have the six.

A narrower track would have to be from wider wheels with more positive offset, the diff itself won't be narrower.

Let us know if you do find a simple solution.

[76lxhatch]

UC Salisbury (non disk brake) and LH/LX fine spline Banjo axles are interchangeable, same bearings etc. Obviously coarse spline don't fit the Salisbury unless you want to downgrade it by changing the side gears

[yel327]

UC drum brake axles are the same as LH-LX, only snag will be if they are disc brake axles.