Quote:
Originally Posted by Lovel
Manufacturer tooling doesn’t last forever, and can wear down. It’s super expensive to re-tool, hence tempting for these companies to stretch the life of the tooling.
Consider this if LUK was the original supplier to MG Rover since 1998, has the moulding been updated since then after probably 100’s of thousands of pressings? Slight tolerance variation on a probably very tight tolerance component here would easily result in failure earlier in life. Excess flashing from worn tooling of the plastic housing could cause elastomer failures quite quickly.
As an example anyone (ok with much wider tolerances) that has seen the rear wing of a P6 will understand this as the later pressed wings from the original worn tooling are a mile away at the shut line compared to the original pressing.
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I doubt very much if the original tooling has past its sell by date yet, I am currently moulding on tooling with at least 10+ years on the original Rover tooling without issue.
I feel the issue will be the material and processing involved rather than the tool itself, the housing for the slave cylinder is made from nylon 6.6, now a good quality Nylon costs in the region of £1.80 per kg, I know suppliers of an 'Equivalent' material where the price is in the region of £1.10.
The difference to mould the two materials is like chalk and cheese, Nylon is a swine to mould even when using the best polymer, if you choose a lower priced material, you will not have the benefit of the in built stabilisers in the material, thus it will be harder to process and the moulding conditions will vary.
The two parts will look very similar when placed side by side, the weight would probably be within tolerance too, the only difference would be moulded in stresses that would not be visible to the naked eye, could this be a reason for the failures of new slave cylinders? Without knowing what materials are used, and without seeing the process we can only speculate.
As an aside, many years ago I made plastic parts for use in the space shuttle program and also moulded ball joint covers for Austin Rover at the same time, and the same material supplier supplied the polyurethane for both
