Featuring Quality Restoration Help For Mercedes 300 SEL 6.3 Owners And Enthusiasts
J Haynes Auto TechnicsEirene Garage
TEL: 01903 500000
Kienle AutomobiltechnikD-71254 Heimerdingen/Stuttgart
TEL: 0049 7152 52827
Star Motors1694 Union Center
Maine Highway Rt 26
TEL: 001 607 786 3918
For advanced coolant. I highly endorse this coolant.
(ILS Engineering ltd)
Bullford Business Campus,
TEL: +353 1 2875859
For wood repairs and finish.
City Polishers Ltd
TEL: 01406 380984
For all engineering work, engine reconditioning and rebuilding, vapour blasting and metal spraying.
Pear Tree Farm
TEL: 01234 352418
For zinc plating.
6 Priestly way
TEL: 01293 528974
A S Pickering
For car trimming and headlining.
A S Pickerings LTD
TEL: 01274 724000
Tower Bridge Diesels
For mechanical fuel injection pump servicing and repairs.
Tower Bridge Diesels
TEL: 01472 827632
Kelly Bray Steering
For the reconditioning of the power steering box.
Kelly Bray Steering
TEL: 01579 382766
For electronic ignition.
1 Hoskins Place
TEL: 01276 65554
Dorset Aluminium Products
For the chemical brightening of the exterior trim strips.
Dorset Aluminium Products
Poundbury West Trading Estate
TEL: 01305 265235
For the chemical brightening of the exterior trim strips.
Colour Anodising Ltd
TEL: 0161 723 2637
Vintage Tyre Supplies
For hard to locate tyres.
The National Motor Museum
TEL: 01590 612261
Newton Hose Supplies
For the friendly service and many hours put into the air, fluid pipes and hydraulic hoses.
Newton Hose Supplies
Rydon Industrial Estate
TEL: 01626 361118
Phoenix ContractsFor all air, fluid pipes and hydraulic hoses.
TEL: 01795 420594
The Restoration of the Mercedes-Benz
The original owner of the classic car was 1960/70's pop icon Donovan. The restoration of the Mercedes-Benz took approximately two years, although of course work is always on going to keep the car up to standard.
This webpage and some others on this website are designed to provide help and advice in maintaining and restoring these flagship Mercedes-Benz saloons. Please email if you would like any advice or parts location on these cars. Hopefully I will be able to help.
For many enthusiasts motoring journalists or just general admirers this model was and is still classed by many as Mercedes-Benz flagship Saloon. Perhaps its the timeless elegant styling that has helped it maintain this position, or maybe the mighty 6.3 German V8 engine shoehorned into the body which has had more influence in its status.
Whatever way you view the car it cannot be denied that this model of car which was designed in 1967 was very advanced with its fuel injected engine and self levelling air suspension. Built in times gone by when more emphasis was on quality components. This car was for many years the fastest Saloon available.
For those interested in the full restoration story then please click below.
Carrying out a Full Restoration
Carrying out a full restoration took around two years. Shortly after the restoration it was featured in a few magazines as well as mentions on the Bob Harris Show on Radio 2, and Capital Gold. The car has also been featured on the Mercedes Enthusiast calendar, and been on display at Mercedes-Benz World Surrey. It is a wonder that the car was still around to restore after its hard life especially as it was left outside in fields at the mercy of English weather for approximately five years after Donovan sold it.
The car has been restored using original parts, although the points and condenser have been replaced with Pertronix electronic ignition. This was fitted to achieve a more reliable ignition system which is adjustment free.
To retain the original feel and period celebrity vibe of the car the leather interior has been kept along with the original carpets. I felt this was important as although carrying out a full restoration I wanted to retain some of the period vibe. The leather has been re dyed and is regularly coated and kept at a good humidity to keep it supple. Despite some small blemishes it is generally considered that the leather interior is in very good condition for the age and the previous very hard life of the car.
A lot people who hire the car as their main wedding car like the fact that they will be sitting on the same leather seats as Donovan and George Harrison once sat. They like to see that some of the original history of the car has been kept. The interior wood sections which were in very poor condition have been renovated back to original. Most of the exterior trims and chrome work have been replaced or re-chromed.
Hire the Classic Mercedes JMO 9K
As can be seen from the long rear doors it was a car built to be chauffeured in. Anyone who hires the classic Mercedes-Benz JMO 9K is very soon aware of the extra leg room which is very useful for a Bride with a large wedding dress.
The large 6.3 litre twin camshaft fuel injected V8 engine delivers plenty of power and torque. Acceleration of 0-60 mph is approximately 6 seconds. On a constant 60 mph you can achieve 12 mpg, around town approximately 8 mpg. It is possible to cruise at 90/100mph quite comfortably.
Their were only approximately 650 of these classic Mercedes-Benz cars made in right hand drive. Over the years most have been broken up mainly due to a combination of very high restoration costs, technical complexity and hard to locate spare parts. At present market prices (2006) it is often uneconomical to fully restore these cars as the restoration costs far outweigh what they are presently worth.
This Mercedes-Benz 6.3 is classed as one of the best right hand drive models in existence. The car is complete with the original sales brochure, Logbook, pink card, many tax discs and MOT certificates as well as the original German oval shaped plates. There is also a photograph of the car parked next to a Rolls Royce used by the Beatles. The car still attracts lots of attention from all ages when on the road.
Hire the classic Mercedes JMO 9K, and feel the period vibe.
Restoring aluminium window and windscreen trims 'Chemical Brightening'
Many enthusiasts reading this will no doubt have polished aluminium surrounds on their front and rear windscreens and window surrounds which are either scratched or quite tarnished. In many cases when it comes to restoration some sections are still available new, but many are not. The chances of locating these sections secondhand which are about forty years old with a decent shine and dent free are fairly remote. These sections can be restored back to the same finish. If your section has got a dent in it then you will have to locate another as the restoration process will not remove dents. During the restoration I had to do just this. It does not matter it the section you find is badly tarnished or with small fine scratches as these will polish out.
These sections are not just chrome plated or polished and lacquered as many think they are. The process is called ‘chemical brightening’. The restoration of your aluminium section involves polishing it until it is smooth all over and free from pits, scratches etc. It is then placed in a chemical bath where it brightens, hence the name ‘chemical brightening’. The section is then anodised to stop it corroding. The whole process is not that expensive and does not take that long, as far less work is involved than say something like chrome plating. Years ago in England there were quite a few places operating this service but due to changing health and safety laws many have closed down.
Cleaning of various different steel items
When it comes to cleaning up various different steel bodywork or suspension items It is nearly always best to have these grit blasted and sprayed with a zinc primer. This provides a decent rust free surface all ready for spraying. Small items can often be cleaned effectively with a wire brush wheel on a bench grinder, providing the rust has not deeply embedded itself. Basically grit blasting can save you much time and is a far better way of cleaning.
As most of you are aware this is often an expensive process due to the work involved in re chroming. There are cheap places to get items re chromed especially in some countries abroad. But be warned!! most of the cheaper places often do not carry out all the preparation and nickel plating fully prior to the final chrome plating. The other thing to bear in mind is would you be prepared to send your classic car parts abroad to places that might not speak English, and trying to sort things out if something did get lost. I have listed London chroming who I have been using since 1983. The inside of the bumpers should be finished in a light beige paint (Mercedes-Benz have a paint colour for this). It is a good idea to clear wax the light beige paint and bolts to avoid corrosion.
Air suspension valves
Many people with these cars find that they start to sink down over night or over a couple of days, in other words there is a leak somewhere in the air suspension system. There are many different joints and valves which cause a leak and it is often best to use foam leak detector to find the leak before purchasing any valves or often other expensive spare parts. It is always best to check that all four air bellows are ok. Another thing to bear in mind is that people think that they have a leak from the bellows when in fact water has worked itself in-between the face of the bellows and the steel air chamber. This often causes rust which in turn means that the mating face of the bellows does not sit tightly on the air chamber. Another thing that can cause air leaks is where past owners have taken a valve off or pipe and not replaced the ‘o’ ring inside the joint. On most of the air system a standard o ring is used but on some parts flat faced o rings are used, so make sure you replace with the correct type. Whenever you take a joint apart always replace the o ring.
Personally I replaced all my original steel air pipes with copper nickel pipes. I know this is not original but the obvious advantage is that they will not corrode. Having all these made up and bent to exactly the same shape as the steel ones was quite difficult and time consuming, however they do look good and are corrosion free. The air pipes were originally sprayed with a dark green paint. This green is the same green finish as the brake pipes. I decided not to spray the green paint on the air pipes as I was concerned that this paint would eventually start to come away from the copper nickel pipes from engine bay cleaning and lack of adhesion over time and thought this would look untidy. You can see an image of the engine bay below with the air pipes fitted. As a matter of interest apart from the air pipes the only other thing that is not original on my car is the pertronix unit. This was fitted to vastly improve the ignition.
Fuel injection pumps
When restoring the car the injection pump will need to be overhauled and re set. I can understand that a lot of people may not want to take the pump out and then re fit it ensuring the timing is correct, but for those who are capable and for those who would prefer to take it to a garage to have it taken out then the contact I have listed is very good. You often don’t need to send your pump off to Bosch to have it reconditioned as most just need to be re set or repaired. It is only nessicery to remove the near side air tube (R/H drive) in order to take the injection pump out.
Once your pump comes back and it is re fitted you will in most cases need it to be adjusted to suit your engine, this involves unscrewing the large nut at the back of the pump with the knurled collar sticking out of it. The knurled collar is for the mixture adjustment when first starting the engine, in other words if the engine will not idle when the pump is re fitted then the knurled collar will have to turned a click at a time. DO NOT EVER TURN THE KNURLED COLLAR WITH THE ENGINE RUNNING, ALL CLICKS WITH THE KNURLED ADJUSTMENT COLLAR MUST BE DONE WITH THE ENGINE STATIONARY. Once the nut is off the mixture adjustment screws can then be turned one click at a time for both high and low engine revs. This will need to be done by someone with the correct testing equipment. I have listed Tower Bridge Diesels who I used, they will also clean and test the injectors.
The back axles on these cars are fairly complicated for their day. You often hear how Mercedes-Benz 6.3 axles have been removed for repair. This main reason for this happening is that some owners cannot resist the temptation to put there foot hard down from a standing start and of course with 1960’s 1970’s technology without modern day traction control you run the risk of spinning the wheels and or stripping some teeth inside the differential, and in some cases snapped half shafts. My own Mercedes 6.3 has had the axle out three times for repair. I hasten to add the last time it was taken out was for a complete overhaul. So in other words do not put your foot down hard from a standing start, wait for the car to be travelling first.
Here are some main points for the axle. Although the following jobs I have listed below can be done with the axle in place although it is often easier to take it out for better access, especially if you are intending to replace most of the rubbers and anti dive bearings. If taking the axle out and apart it is obviously best to replace all the oil and grease seals as well as bearings if the bearings are a number of years old and showing signs of wear. Over the years the large rubber which sits on the bracket going to the differential squashes up, goes hard and perishes as is the case with most rubbers over the years. This can have the effect of making the axle sit at the wrong angle, push upwards and damage the mounting between the two prop shafts, as well as the rubber make a squeaking noise. This rubber is replaceable without taking the axle out of the car. The anti dive bearings are the plastic bearings which are located at the end of the axle next to the wheels. There are four large Allen key bolts per bearing.
These plastic bearings often wear out as they are not greased often enough through the grease nipples located on the bearing cases. The two large rubber bands each side of the bearing cases stop the grease from escaping and the ingress of dirt into the plastic bearings. These rubber bands often perish and allow dirt to get in and grease to escape easily. The anti dive bearings and the rubber bands can be replaced with the axle in the car, after removing all the brake assembly. With the brake assembly off it will allow room to get to the Allen bolts, however these are often rusted in and often require heat to loosen them. The Allen heads will often also be corroded out so either a spline tool or chisel will be needed to remove them along with some heat.
The large rubber bellows which is held on with the two jubilee clips can again be replaced with the axle in position, and often many people use the split bellows that can be glued to avoid having to strip one side of the axle. The adjustment bar which goes from the chassis to the differential should obviously be adjusted correctly, and details of this are in the workshop/service manual. This bar has large rubbers which again over the years go hard and perish and should be replaced. The rubbers on the swinging arms should also be checked for signs of wear. Basically worn rubbers can throw the geometry of the axle out.