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350SLC Recommissioning

This 1979 350SLC came to us from a customer in Alabama in November of 2012. It had been well-maintained, but showed the usual issues expected from a vehicle of its age that had never undergone a thorough rehabilitation. 

We noted the following issues upon initial inspection:

Cooling System

The water pump needed immediate replacement. We also recommended replacing the cooling and heating system hoses and hose clamps in conjunction with the water pump replacement. When replacing hoses, we pay particular attention to metal connections, removing any corrosion for best sealing. Following this work, we recommended installing a flushing “T” fitting and flushing the cooling system with clean water before filling the cooling system with a fresh mixture using Mercedes-Benz factory anti-freeze. 


Upon inspection [initial engine inspection] we were concerned about the amount of stretch on the timing chain. We advised immediate replacement of the timing chain. In conjunction with the timing chain replacement, we recommended a new timing chain tensioner. We recommended that the camshaft oiler tube connectors be replaced while the valve covers were off; these are made of plastic and get brittle. 

The starter made terrible sounds when rotating. We recommended that it be replaced sooner rather than later. 

Two nylon accelerator linkage bushings were observed to be crumbling. Replacement was recommended, to improve engine performance markedly. 

The paper air filter element was dirty and needed to be replaced. The plastic vacuum lines and their rubber connectors under the hood were brittle and also needed to be replaced. 

We also recommended replacing the rubber front and rear motor mounts in conjunction with the water pump replacement, because there is good access when cooling system components are out of the way. 


Although the bushings at the transmission shift rods were already new, the nylon shift lever bushings in the gear selector quadrant were noted to be worn out. A bushing for the transmission pressure control rod was also missing. 

We also noted that it would be ideal to replace the rubber transmission cooling hoses. This job is best done in conjunction with changing of the transmission fluid and filter. 

A change of the transmission fluid and filter was noted as highly advisable. 


There are two flexible rubber discs on the driveshaft – one on either end. The front flex disc was observed to be cracked; we recommended that it be replaced, and that it would be ideal to replace both the front and rear discs. Since the driveshaft would be loose at either end, we also recommended replacing the driveshaft center bearing and its rubber mount. 

We observed a loss of rear axle fluid through a leaking seal on the right side of the differential, and recommended that this be replaced to stem the fluid loss and protect the differential. 


We recommended that the front and rear brakes should be serviced, and pads replaced if necessary. 

Additionally, we noticed that the front and rear brake hoses were original, and the rear ones were damaged. These rubber hoses swell internally, constricting the flow of brake fluid. New hoses were in order, followed by a renewal of the brake fluid. 


The customer noted play in the steering. Our inspection revealed that the coupling between the steering shaft and steering box was worn out, and needed to be replaced. We also noticed that the steering dampener is no longer dampening. Also related to steering linkages, a new intermediate steering arm bushing was recommended, followed by a front-end alignment. 

The front wheel bearings were slightly loose. Minimally, these needed to be tightened. Ideally, the bearings would be replaced and packed with new grease. 


The car came to us with a tired and decaying exhaust system. We recommended replacing the complete exhaust system. A stainless steel exhaust system is a cost-effective solution, that will not need replacement again. In these times, we also appreciate that these systems are made in the USA. 

We view these jobs as the most pressing. Although we are making additional recommendations for your automobile, such as those listed below, many of these items fall into the category of improvements to be addressed somewhat later. 


The driver’s seat back frame was damaged. These frames cannot be readily repaired, so we suggested a replacement frame, new or used, or having the customer’s new seat cover transferred to a good used driver’s seat. 

The fader switch was incorrect. We recommended that we supply a proper fader switch so that the console has correct appearance. We noted that we could endeavor to smooth out the carpeting skirt on the driver’s side of the center console, and source replacements for damaged horizontal burl wood trim pieces. 

Electrical Items

We noted several electrical issues in need of attention. The heated seats and console illumination were not operational. The two standard horns were missing, and needed to be replaced for safety reasons. 

The odometer was not functional. We advised that the speedometer can be shipped to the VDO repair station for repair of the odometer. The actual accumulated mileage reading could be corrected at that time as well, and the speedometer recalibrated in conjunction with instrument repairs. This would be done after new tires were purchased so that we could calculate the necessary correction factor. 

We noted that there are superb replacement headlight bulbs available for this car. We consider good lighting to be a safety item, and a priority. We noticed, too, that the left tail light lens is cracked, and offered to source a replacement lens. 

Other Items

The customer’s other concerns, such as air conditioning, wind noise, trunk lid deterioration, etc., would also be addressed. 

We also suggested replacing the engine hood hinges, as those on the car were not correct for this model. 

At this time, the customer signed on for the full program we had laid out, so we began.