450 CDI big service

7 posts in this topic

So im going to do a big service on my car this weekend. The car had no service records(90,000 km). The car was sitting for about 2 years before i bought it so it should drive a lot better after i have done the work.


-Oil + filter(5w-40 synthetic is in car):

im going to replace with 0w-40 rotella t6 and a new stock filter(its tiny) next time i will do the spin on filter upgrade.


-Transmission fluid

Full synthetic moto master dextron VI, 1.4L. Dextron VI is backward compatible to Dex III and Dex III is back ward compatible to Dex II(what MB specs)


-Fuel filter

I will have to swap the water filter over and be extra careful not to get it wet.



I tested the coolant and it is good, I might replace in summer with an additive for piece of mind 


-Bleed brakes 

Dot 3 simple bleed



lithium spray actuator

lube locks/hinges

polish headlights


This website is really useful.

Ill roughly document it here

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Good service and good maintenance is essential to keep these wee cars running problem free. Grease socket in clutch release arm to prevent corrosion, wear and punch through. Service clutch actuator but do not over grease. Glean areas where rubber boot seals against rod and clutch actuator housing and apply protective silicone grease in these areas as mineral grease will ruin rubber. Inspect transmission wiring harness and ensure all is securely fastened not chafing anywhere. Correctly preload clutch actuator.

PS1. Clean and grease threads in transmission for fixing actuator.

PS2. I also paint clutch actuator body. Exposure to salt treated roads do actuator no good and I've seen far too often that the fixing lugs corrode and snap off leaving the poor smart owner stranded.

PS3. Since starting to apply silicone grease to areas where boot seals, I have seen no more actuator trouble with the Smart cars so treated. The silicone grease effectively seals against ingress of dirt and water.


PS4.  Alternator pulley is aluminium and wears out fast.  Consider replacing with freewheeling pulley. Whisperquiet idle, lower fuel consumption, quicker and slick gear changes and faster acceleration. 




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There is no benefit going for a spin on filter.  I prefer standard replaceable element oil filters because I then can easily inspect for foreign objects and metal particles on the outer surface of filter.  Not easy with spin on filters as they have to be cut open so never done.

Inspecting for metal particles is important on 2005/2006 Smart 450 Cdis due to the fiasco with Smart building engines with bad oil pump sprockets.

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Stickman's pulleys. One good and one bad.


Is yours in a similar state as the bad one?

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Thanks for the helpful reply tolsen, ill have a look at the pulley and if it seems ok ill hold out until the summer to replace. Ill do all the other stuff mentioned too.

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Posted (edited) · Report post

This was the state of the car (dirty, blocked off cabin air intake and top rad intake)


The underside was much worse and when i went to the car wash there was a huge line so i had to rush and didnt do a good job cleaning it.


-For the fuel filter it was easy, the only problem i had was the bolt that holds the bracket to the car, i got it half way out then rounded the head. Not a huge problem but now the filter holder is a little loose(bolt wouldn't come out).


-Trans fluid was really easy too, only problem was I used a very small hose to refill it so it took about 30 mins of slow pouring the atf into the hose.


-Oil change was going well but after taking off the filter, barely any oil drained(~500ml) and my hand pump would have taken an eternity to pump the rest of the oil out. Im going to get a local shop to suck the oil out at 8:30am tomorrow morning for $10.  Im going to see if they will take out the fuel filter bolt i rounded and replace it for cheap, if not its super easy to get to so i can just buy a tool and do it.



I did most of the other simple stuff but because the underside was so dirty i couldn't paint or lube the underside without risking extra dirt ingress along with the lube. Ill sponge clean it and lube the underside tomorrow. As for adjusting the clutch actuator im worried the bolts will break and have to work tomorrow afternoon so i will wait for a break and warmer weather before I try.


Edited by RobCDI

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There is no point changing transmission fluid on these cars unless contaminated by water.  Transmission has a large magnet inside that will collect metallic particles.



The highest loaded bearings are rubber sealed grease lubed so won't benefit from fresh oil. Transmission fails when the grease in the sealed bearings dries out.


My transmission opened out.  I replaced all 6 ball bearings.  Fitted open unsealed bearings so now all are oil lubed.

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