Page 17 - Beep Beep april 2022

What’s going on in the shed?
This month Noel solved his DIFF RATIO PROBLEM
One of the downsides driving pre-war cars is the inability to keep up with the traffic on the open road due to their original diff ratios of 4.45 etc.
I can’t quite understand the manufacturers logic behind this selection but can only assume it was poor foresight or they had a massive oversupply of these particular crown wheel and pinions to use.
After searching countless hours for a better ratio Crown wheel and Pinion I gave up and decided to take the drastic step of swapping the complete rear axle assembly for a better outcome. After doing lots of research I found a VL Commodore Wagon assembly was exactly the same width and came standard with a more desirable 3.45 ratio.
Not one for irreversible modifications, the original rear axle assembly was kept and can be re-fitted at any time.
I fitted the Commodore assembly with some of the bracketry removed and minor modifications to the donor H-brake cable length, new spring saddle mounts fitted and new hydraulic brake lines from the original flexible hose mounting. I had a machine shop re-position the wheel studs in the axle to suit a slight difference in the Oldsmobile stud pattern and had a flange adaptor plate made to couple the 2 types of driveshaft mountings. I also utilised the Commodore’s original Panhard rod by making a bracket that fitted to the existing Olds shock absorber mountings.
The change in drivability is enormous with a noticeable ease in keeping up with the rest and a lot less noise from the previous over-revving side-valve six. The swap had a cost around $1,000 – well worth it in my view!
Cheers : Noel
Photos from Noel
St John-Wood
Have you got a ‘shed story’ to share ? The Editor would love to feature it : Send info to – editor@roadrunnercarclub.com;au
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