20 November 2011

Week 3 50,000km service

Hi Guys
I received the parts from the USA! Went very nice and smooth. Just 8 days from ordering in USA to delivering in Adelaide... and the parts are so much cheaper... anyway, at this stage I can recommend AutoHausAZ very much.

Anyway, the arrival of the stuff was the start shot for a list of maintenance jobs. Some are in the 15,000km and some are in the 50,000km service. I attended to most of them and will complete the others in the coming weeks.

Drive belts
My 450SL has a double drive belt going to the Power steering and water pump (B). A single one to the Air conditioning compressor (D) and another single one to the Alternator (C).
Only the (B) power steering pump double belt looked ok, the others looked very old and very cracked. Although it might be easier if you remove the radiator and shroud, I found it fine by just leaving this on the car. So loosened the auxiliary components (the fancy name of the pumps, compressor and alternator) and removed  the belts. This was quite easy. Then compared the sizes to the ones bought and they were all a bit different, but I guess this does not matter that much 9.5mm fitted, 10mm supplied as compatible...
Looking at the photo on the left, you can see that this was for me a priority job...
Fitting the new ones was a bit fiddly. Of course they have no stretch, so I ended up having to remove a bolt of the Alternator (see red arrow). This gave enough slack to fit the belt, and was then easy to refit once the belt was on the pulley.
The other tricky one was the air conditioning compressor belt. I ended up removing the tensioning roller (5), once that was done, it was easy.
So once all fitted, tensioned them as tight as possible, for this a second set of hands is highly recommended. One can hold the tension the other can tighten the bolts up. They then recommend to turn the engine over by hand at least two full turns. For this I need a socket 27mm that I don't have yet, so instead unplugged the coil lead, and just used the starter motor to turn the engine over without wanting to start it. Rechecked the tension and all done...

Spark plugs & Leads
On the forums there are a lot of stories about this. Basically the recommended practice on the forums is to stay with how the car came out of the factory. That is, the spark leads have a resistor in the spark plug cap of about 1k ohm. The sparks themselves should not have any resistance. So this is how it was and this is the recommended way according to many forum members.
The kit of all the leads is Bosch B6040i and the spark plugs are Bosch W7DCO or NGK BP6ES.
But... As I had to wait a while for delivery, I just went to the local Mercedes garage to pick some up. The service bloke handed me Bosch WR7DC, but these are resistance one (WR instead of just W). He said that's what they've been fitting to the 450 SL's for the last 15 years and never had problems...
Interesting... according to the forums, having too much resistance (lead and plug), gives a smaller spark, having no resistance gives static on the radio (among other side effects).

Anyway, found that the NGK BP6ES were just a stock item in Supercheapauto so picked them up, and fitted the lot. Some of the spark plugs were a bit fiddly but with some flexible joints and extenders, I got them all out.
Some more on resistance, the plugs that I removed were also exactly BP6ES, but the leads had no resistance... Interesting. Anyway some spark plugs were very loose and as you can see above, some look better than others, but generally they don't look too bad I guess. They are shown from left to right cylinder 1-4 and the next picture 5-8.
After fitting the new plugs and leads, the engine runs like a dream... Previously it did not run on all 8, causing loss of power and shaking of the engine (on worn engine mounts). Now it runs so much nicer...

Power steering filter
This seems to be one of the many forgotten items to service especially as the filter is sunk in the bottom of the reservoir. Anyway I used a suction gun to empty the reservoir and used pliers to lift the filter out. It's a pity that I did not take a picture of the old filter... lets say it was well overdue.
The fluid looked fine enough (the Steering gear was overhauled just 6 months ago) so pushed the harvested oil back in the reservoir. Placed the missing seal under the lid and closed all up again.

Air filter
The air filter also looked worse for wear. I nearly fell over when a carshop around the corner wanted $120 for one of their home brands that would fit... Good that I ordered an OEM for US$ 15.75 don't know how that is possible and how its sustainable but there you go...
See on the photo, the nice new one fitted and the old one next to it, I bet the engine will have a sigh of relief.

Positive Crank Ventilation
The Haynes manual states to disconnect the PCV hose and take a spring (flame guard filament) out. When I remove the hose of there was no spring underneath... Need some further investigation, added to the list of next week.

Engine & Transmission oil
Took the car for a nice drive with the new spark plugs, leads and air filter, and must say it runs very nice indeed. Filled up for 98 octane and added the lead additive. Still not sure if this is required, but the previous owner gave me the bottle so I guess it does not hurt.
After the car had a good 30 minutes run, it was nice and hot and I had my driving kicks (it was a nice 33 degrees sunny day), I lifted the car on the hoist and removed the sump plug. When the stream turned into a trickle I undid the oil filter but gee, that thing stays hot for a long time. Next time I will wear thicker gloves...
I just let it drip while I focused on the transmission oil.
Took the banjo fitting of the filler pipe off and drained about 2 liters. Then undid the pan and tried to remove somehow without burning ourselves while this pan was still full of very hot oil... It was not ideal but nobody got burnt... I think I might have to wait for the removal of the pan until the oil has cooled down...
Then I cleaned the pan and dried with compressed air. Fitted the new transmission filter and placed the pan back with some sealant and the new rubber gasket.
Also fitted the banjo plug back with a new copper seal ring, as well as the engine oil sump plug with a new copper seal ring and a new oil filter.
Then it was time to refill. The engine took just under 8 Litres, while the transmission was already over the level with just 4 Litres. This needs further investigation...
Took the car for a drive and it goes nice...

Ballast resistor
Although I was not sure that it was broken, I replaced the 0.4 Ohm ballast resistor. It was cracked and could have been one of the causes that the previous owner was so afraid of getting the engine cleaned. As you can see it did not look all that flash... When I measured the resistance it was all over the place. Depending on the force in the connections it went from no resistance at all to unlimited. Good I replaced it I think.

Taking the car for another drive really indicated to me again that the steering linkage and the suspension rubber as well as the engine mounts are all very dried out and need replacement. I placed an order in for the parts, so probably in week 6 I should be able to replace large parts of this and return the suspension back to what it should be...

Plan for week 4
- Get some good quality replacement speakers (I know, not important in general, but important to me)
- Clean up the inside with a good vacuum, perhaps even remove the seats.
- Find out if the PCV should have a flame guard filament
- Make a plan for the suspension removal when the parts arrive the week after
- Replace the rear diff oil and leaking seal

Cheers and hope you enjoy my blog