I need to replace the rear axles in my '81 240D. How do I tell if it has the homokinetic or the annular half shafts? And how difficult a DIY job is this? As for experience, among other things, I can wrench my '53 pontiac and '79 Fiat. Which manual will be best for step-by-step instructions?

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240D '81 265K
300SDL '87 81K