Looking After the SM
Let’s put this plainly: for annual maintenance, expect to invest between €500 and €3,000 for upkeep on an SM. This cost varies depending on the car’s condition, maintenance frequency, and your location. However, be aware that a Maserati engine overhaul can easily exceed €10,000, and if the transmission needs work, you could be looking at €15,000 or more.
So far, we’ve been fortunate to enjoy our SM with minimal investment. Alongside regular maintenance and a major upholstery makeover, we’ve addressed only a few key issues: overhauling the suspension cylinders, replacing a height corrector, stopping pesky rear brake leaks, and reviving the air conditioning, which had succumbed to a tired compressor. We also upgraded to a set of robust stainless steel silencer pipes. A preventative engine overhaul is planned soon, and we’ll keep you posted!
Whenever you decide to look for an SM, keep in mind that while its body boasts a tougher build than the DS and has much-improved resistance to rust, it’s not completely immune. The rear section, in particular, can fall prey to decay, so don’t forget to check beneath the boot floor carpet for any lurking issues. On the bright side, sourcing spare parts for an SM is relatively straightforward, much like the DS, although your wallet might feel the pinch! Specialists in France, the Netherlands, and the UK are excellent sources for these parts. If you become a member of the SM Club de France, you’ll benefit from remanufactured parts at reasonable prices.
Our ultimate advice? Avoid incomplete cars and steeper-than-average deals when eyeing an SM. A thorough inspection of the vehicle’s completeness and condition is essential before you make that leap. Regarding hydropneumatic components, similar recommendations apply as for the DS. Dedicated clubs and various resources are available to assist you in the joys of buying and maintaining an SM, although not all of them are in English. Here are some links to help you get started:
While many online videos spotlight the SM, the rlbatch1 channel takes a deeper dive with comprehensive servicing instructions that are truly invaluable. I can’t help but admire Sean Patrick’s insightful articles on Driven To Write, which brilliantly capture the essence of this iconic motor. And let’s not forget the buzz surrounding the freshly restomodded SM2 by Gallet Automobiles. It is an exciting time for SM enthusiasts!
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Key Data for Routine Maintenance of Your 2.7 Carburetted 5-Speed SM
- Fuel tank: 90 litres petrol.
- Engine lubricant: 7 litres 20W50 mineral oil (6 litres if the filter is not replaced).
- Transmission lubricant: 2.25 litres SAE 80 gearbox oil.
- Hydraulic circuit: 5.4 litres LHM fluid.
- Engine coolant: 13.5 litres.
- Spark plugs: gap 0.6-0.7 mm; original: Bosch W 200 T 30, replaced by: NGK BP6ES / Bosch W7DC / Bosch WR7DC+ / Champion N9YC.
- Battery: 70 Ah.
- Tyres: Michelin XWX 205/70 (originally 195/70 for the carb version). Recommended pressure front/rear: 33/30 psi.
- Suspension sphere pressure (front/rear): 40/26 bars (split spheres).
Low-Mileage Operating Intervals
- Yearly (max 5,000 km): change the oil and filter, lubricate doors, bonnet, handbrake, horn, distributor.
- Every 2 years (max 10,000 km): yearly maintenance + renew coolant, lubricate front suspension and steering (at 10 points). Check, adjust, or replace: spark plugs, contact points, drive belt tension/condition.
- Every 4 years (max 20,000 km): 2-year maintenance + renew gearbox oil, renew LHM and clean filter with petrol and air (max 30,000 km), lubricate rear suspension ball bearing, clean air filter, blow clean the water and oil coolers, lubricate height correctors, front wheel alignment, tyre balancing, check, adjust, or replace: fuel pipes, 6 hydropneumatic spheres, parking brake, brake pads, hydraulic hose connections, ground clearance, front suspension, and steering components.
- Every 10 years (or when reaching the annotated km): 2-year maintenance + check valve/tappet clearance (max. 10,000 km), replace fuel filter (max. 20,000 km), replace distributor capacitor (max. 20,000 km), replace ignition coil and change all drive belts (max. 60,000 km), check front suspension ball joints, steering rods, and rear swinging arms for any play, adjust clutch clearance.
- At 20,000 km: adjust the tension of secondary timing chains.
- At around 60,000 km: 20,000-km maintenance + replace the primary timing chain and its tensioner.