Many cars have electric windows and a few have air-con, while most feature central locking. While many W123s didn’t feature a lot of kit, what is fitted tends to be reliable. Interiors get damp because of failed windscreen seals and the complex front seats can collapse, especially the driver’s. With each finish offered in a variety of colours, tracking down matching replacement used trim is virtually impossible.
There were five different trim finishes MB Tex (a tough leather-look vinyl), velour, leather, half-cloth (mixed with vinyl) or full cloth, while on coupés there were standard or lowered seats. On estates the tailgates rot and so do the fuel tanks replacements are unavailable.īumpers corrode badly, from the inside out, while cars with a factory-fitted sliding sunroof (which is most of them) need particular scrutiny as the roofs can leak and the drain tubes rust, allowing water to be chanelled straight into the footwells. Also check behind the headlights, around the front suspension mounts, the inner front wings and in the rear wheelarches. In the case of the former, if left to corrode it’ll take the bulkhead with it. The areas most likely to give problems include the battery tray, spare wheel well and jacking points. Panel availability is good, although some pattern stuff is ropey so it’s best to stick with genuine parts, which cost far more. But pre-1981 cars can rust badly and even later W123s are likely to have some corrosion. The W123 was fairly well protected from the elements, while the paintwork was unsurpassed. Master cylinders can also fail but replacements aren’t expensive. It’s a straightforward system that shouldn’t give problems, although calipers can seize, leading to a soft pedal and a lack of reassurance when slowing. Estates came with self-levelling suspension at the rear if this fails it’s very expensive to put right.Īll W123s feature servo-assisted discs all round. To remove the hubs you’ll need a special tool to remove the rear wheelbearings, so it’s a job for specialists only. Repairs mean removing much of the rear suspension, complete with the hubs. Make sure there’s no play because if all the adjustment has been taken up, a costly new box will be required.Īny car on its original rubber bushes will need a fresh set, while rot is common in the bottom spring mounts for the rear trailing arms. Power assistance was optional for the recirculating-ball steering until 1982 then it became standard, although most cars had it from 1978. And once again, it’s always best to stick with OE parts.
The rest of the transmission is very strong, which is just as well because a rebuilt diff is big money and so is an OE clutch kit. All these transmissions are extremely long-lived, so any whining or signs of vagueness/jumping out of gear means the car has probably been to the moon and back, and the chances are it hasn’t been serviced properly either.
Most W123s came with a four-speed gearbox, manual or auto, although some facelifted (post-June 1980) cars got a five-speed manual. Also ensure that Beru or Bosch lead sets are fitted nothing else lasts as well.Īny W123 engine is straightforward enough to rebuild on a DIY basis, but the overhead-cam 280 unit is complicated (and costly) to overhaul, while the fuel injection systems also need expert attention. A genuine Eberspächer system costs plenty though. Any W123 engine should be quiet and smoke-free the first sign of wear is usually worn valve stem seals, leading to smoking when applying the throttle after the over-run.īeware of aftermarket exhausts, as they don’t last as long, tend to sound tinny and they’re often a nightmare to fit. The 250’s four-choke carb is a pain to set up properly and despite a reputation for indestructability, the four-cylinder engines typically last just 150,000 miles between rebuilds six-pot editions will do 200,000+ miles. While head gasket failures aren’t rare on petrol powerplants, this 2746cc unit is the most prone of all – and rebuilding a 280 head costs big money. What any previous owner should have done is maintain anti-freeze levels on the 280 straight-six with its alloy cylinder head. The plastic and aluminium radiators fur up you may get away with just flushing it through but if a new one is required, aftermarket items are costly and genuine Behr units are even more expensive. A decent engine rebuild is expensive and decent used engines are scarce. The oil should have been changed every 4000 miles, and the timing chain every 60,000 miles failure to do so means the chain can fail, wrecking the engine.