A customer has engaged us to rebuild his 1974 450SLC. This car has been rebuilt and maintained throughout it’s life including some time off the road in Storage. the paint is tired and flaking off so it will stripped back to bare metal,rust repaired and repainted before reassembly. it’s also rather special in that it will be four speed manual.

The car has been stripped to the bare shell in preparation for Stripping to bare steel .

The shell is very dusty after being in another shop for two weeks.

This is the Sump for the 6.3 M100 Engine .On the right front corner. Oil was leaking through the weld and the side of the pan was full of cracks. All were leaking.

The welds were very porous and leaking badly.

The easiest way to fix all of the cracks and bad welding was to cut the bottom off and make a whole new bottom and weld it in place.

 

The Engine was rolled over to get the Sump off and to replace the crank seals . The crank shaft had to come out ,but bearing damage was revealed.

Number 7 Conrod bearing was flogged out and the conrod bore distorted . The Big end bore was resized.

Careful measuring of the crank revealed it to be free of any damage  so will be cleaned and reinstalled.

The Bores are ok and only needed a light hone to restore the crosshatch pattern. The rings are worn and will be replaced.

to be continued….

A bit Crowded ,the 6.3 is being wheeled into the paint shop for the final Parts of the body repair and paint work.

 

The final coats of paint are on and just need polishing now.

Moved out of the paint booth and taken off the Rotisserie .The shell is now on the hoist to receive all the under pinnings

The 6.3 is now headed into the booth to be finished .Here,it’s on the chassis rack which is on wheels

The Engine bay needed a bit of touch up so here it’s masked up so the paint overspray can’t escape

The finish is Satin Black but here it’s still wet so it looks glossy. This type of paint takes a few days to set properly.

Here is the trans tunnel and I’ve been refitting the fuel and brake lines. All of the clips have new rubbers and the plating restored.

The steering column is in place ,along with the front part of the wiring loom ,Horns and brake lines. The pad on the firewall has been replaced with a new one .All Australian Built Mercedes Car had a black Engine bay.

The cable here is the new generator cable ,with the Cold start Valve ,which is different to all of the later model 220SE’s which have the cold start valve in the intake manifold .

In the lower left of the picture is the aircleaner which has been restored . The brake reservoir has had the bracket restored

The cables,the cold start and flasher relays,ignition coil new brake lines are in place. The injection pump cold start wiring are in place .The Heater feed pipe is in place ,after being remade in copper to prevent it rusting out again . The little plaque on the left inner fender is the Body tag from the Australian Mercedes Assembly plant in Melbourne with it’s Australian only body number.

The Front and rear ends are nearing readiness for installation .

Here is the engine as removed from the Car initially .It needs a lot of oil leaks rectified and the valve stem seals replaced. I did a leak down test and it has good sealing and compression’s on all six cylinders.

a couple of days later and the crank seals have been replaced, The Damper had to be replaced because someone in the past had fitted it in the wrong place(the damaged one is sitting on the frame under the engine. .I have no idea of how they managed to set the ignition timing . The large black bracket is for the air conditioning compressor. All of the hoses have been replaced . There is a new water pump air bleed pipe ,and all of the mounting bolt holes needed to be repaired with helicoils.

All of the exhaust valve oil seals had been fitted incorrectly ,so they leaked badly.

Both intake and exhaust seals were replaced on all cylinders.

The timing chain is worn out as is the tensioner so those will have to be replacedto get the engine performing properly.

This is the inside of the Thermostat housing and as can be seen ,the seat for the bottom part of the thermostat itself has been eaten away over time so it wouldn’t have been working properly. This is very important with the mechanical fuel injection system which relies on the coolant circulating to the injection pump to set the cold and warm running mixtures.

Here, the corroded one on the left is compared with a good part.

Next… reassembling the engine trans together and fitting to the front in preparation for fitting into the car.

I needed a very heavy duty engine stand to support the Engine from the 6.3 project.

I had a heavy engine stand but it wouldn’t hold an M100 Engine ,so the plan was to use the end of a W112 rear axle with it’s heavy bearing and flange .

Normally I’d say this was rare part (very few W112 cars were made)

A length of the axle housing was cut off in the lathe.

The actual axle shaft was then measured to length (250mm) a section of the axle taper was machined flat,so the shaft was parrallel ,then parted off in the lathe.

parted off axle stub Seen here sitting on a base originally from a ute crane (crane on the back of a pickup truck ) These were welded together so I have a face plate to mount the engine.

The axle housing stub was then welded to the engine stand to provide a rotating point.

I then made a Fork,which supports the weight of the engine at the mount arms ,the bell housing end bolts to the two brackets to support the rear of the engine.

Here is the engine ,upside down ,in preparation to repair the cracked sump and leaking rear main seal.

Eventualy i will add a reduction gear to the shaft at the rear so the engines can be rotated. They roll easily enough on the stand but there is nowhere to lock it in place yet.

 

The lour coat has gone on ,4 coats followed by 3 coats of clear.  This will now be flatted back after a weeks curing. The car will then be flow coated ,then polished.

This the first lot of clear coat which has to be flatted ,Sanded smooth then recoated to bring up the gloss and add depth to the Finish .

This is part of a 6.3 rebuild which began as a simple gear box swap,but while working underneath the car i noticed a lot of damage and some really badly repaired accident damage .Apart from rust in the usual places the front cross member was rusted out and the car was 50mm shorter on the left side.This pic shows the state of the left hand side bumper support cross members . Not only bent it was rusted through . To repair it in the past,someone had simply welded a patch over the top of the worst dent and welded the bumper bracket to that.

 

 

 

 

 

 

 

This is the upper part of the inner fender panel ,which was bent back.

The inner side of the rail was heated carefully and force applied to bend the leg back up again.

The outer part came straight with a lot of work.

 

I used a laser to make sure the both sides were even .

The next step was to repair the damaged inner fender and weld up parts where it was torn from the radiator support panel .

As the panels are straightened out it was important to constantly check the chassis was still within specs.

This the left hand outer part of the footwell . It has been pulled back into shape as it was pushed back contributing to the shorter measurement on the left side.

The new parts are shown here temporarily clamped into place to ensure the car is coming back to shape.

Almost there!.

After a few hours work straightening.

I use a trammel to measure from a set position under the chassis where there is a hole which takes one end,this is the other where a set measurement shows the crossmember here is correctly placed.

The yellow arrow points to the trammel rod and the red arrow shows the needle end in the chassis measurement aperture.

The Yellow arrow here points to the laser line where i am making sure the crossmember is fitting level .

As soon as i am 100% sure the crossmember is sitting in the correct place etc,I weld the rear part to the chassis extensions.

The radiator Support panel is now lined up and checked with the laser before clamping and welded into place.

 

The trans tunnel was very badly damaged in the past,probably from a frontal impact,and was 50mm shorter than it should have been.

Inside the car ,various parts were damaged ,such as the heater case and this,the dash board brace where the bolts have been sheared off.

The firewall wasn’t only pushed back,but the welds for the tunnel have been torn away.

The inner fender to firewall end has rusted and where the parts were repalced in the distant past,they weren’t welded but simply brazed together.

 

I removed the tunnel So I could straighten it out and pull the firewall back out again .

 

In the past someone had used heat to try and removed dents in the tunnel,where the black burn marks are.

 

 

The other interesting this was the method used to hold the gear shift in place.

 

The lever was stuck in place with Sika flex.

 

 

 

 

The sika flex was stripped off  and the tunnel put back into shape the shifter base was also bent so that was repaired .

The side flanges where the car is spot welded to the car were replaced as was the front end where it is fuse welded to the firewall aperture .

Under the car,the cross member on the tunnel was bent,so that has been straightened also .

In the spray booth.

This the firewall on the passenger side (Right hand Drive) .The side panel was replaced in the past and Brazed into place. Rust has taken hold so this whole piece has to be removed and replaced.

 

There is rust in the Sill /Rocker section at the front to be repaired.

The hole in the upper edge of this picture is from rust forming behind the jack point on the right hand side.

The mess revealed under the coats of bituminous underseal.

I cut the outer skin off and as can be seen it’s was pretty rough inside.

Cleaned up in preparation for new steel to welded into it.

With the new peice welded in place, a spare guard is bolted in place to check fit .

Next: welding the tunnel into place and repairing the remainder of the rust .

Lots of work has gone into Priming the body. After the first 3 coats of primer to reveal any dents etc ,the bosywork was gone over again to remove the dents as much as humanly possible. This was followed by a coat of polyester to smooth the surface. This took 3 weeks of concentrated sanding to get smooth with most of it actually being removed in the process. Next step was the first layer of actual primer,a 2K high solid,high build primer. This is the polyester coat.

This is the first layer of primer with spots of glazing putty,these are  where low spots have been filled then sanded down  . The light helps high light flaws ,invisible normally.

next step is to apply PVC coating to  replicate the original undercoating .

 

The sills are coated .This is the right hand rear wheel house .

This the right hand rear boot box. These panels are all new and again the finish is done to replicate the original rough textured look.

 

The boot area was stripped to bare metal to remove layers of old paint and bitumin underseal . Here it is 2K primer with PVC to help deaden Drumming

 

outside the boot is masked to prevent overspray from the boot paint landing on the primer.

Boot finished in the correct satin black ,as can be seen it absorbs light….All seams on the new rear panels are seam sealed to prevent moisture getting into the joins and causing rust.

 

Next step is to paint the door jambs and openings with the final base color .

 

The insides of the doors have been coated to reduce noise and prevent rust.

The final layer of primer has been applied and guide coat applied to reveal the last of any flaws that might not be visible until now. the boot and engine compartment are masked off here.

Sanding has begun ,after 8 hours constant work,only the right side was finished…

 

After much body work to get the shell straight and true as possible ,the doors etc have been bolted on and adjusted .

 

Guide Coat is applied before block sanding begins.

Right front mudgaurd has been block sanded .the dark blotches are low spots which have to be beaten back up again .

Finally after much panel work the long process to paint the body has become .

The bare steel has been treated with a deoxidiser and given the first coats of primer surfacer.

 

Fuel pump restoration

The reconditioned parts are laid ,plus two new bearings, O rings for the housing and concertina seal for the Pump shaft .

The armature was tested and the commutator polished ,the mica seperator segments were cut down slightly and the new bearings fitted. 

There are several washers,spring type drive plates and packing seals under the impeller,all designed to last a long time and prevent fuel leaking into the motor housing. 

The motor housing contains the field coils and brushes these were all checked and found to be OK. it was then fitted with new O rings and tested to ensure it was OK electrically.

Lastly ,the pump mount rubber and metal bracket are fitted. As this is a very early injected car ,the pump is mounted on it’s side hence the odd bracket. a new fuel pressure hose is shown here ,A New hose from the tank to the pump will have to be made .As this also differs,in that the hose is screwed into the tank,not simply slipped onto a nipple as the others are. 

HORNS.

The horns were both stripped and the rust and dents removed. the bodies were reassembled after being repainted.

After reassembly they were tested and adjusted for tone. There is a high tone and low tone horn .