.... The owner says it runs great, but needs TLC. Being that this truck is a 3 hour drive from me, I would like to know what to look out for. I have already done a lot of research, and found a lot of info on this site! But I am not sure as to the chances of it being Diesel or Gas (owner hasnt said, forgot to ask him) Doesnt matter to me, but how reliable is each? Trouble spots in the mechanics to look for?
hope this helps - but almost all S404 series trucks are Gas, Mercedes M180 I6 2.8L motors, great motors but not barn burners. If it is diesel chances are it was converted to a diesel in Europe (very rare) and will most likely have the OM617 normally aspirated diesel unless it has a very expensive adapter kit for the turbo diesel OM617A.
Things to watch for -
Gearbox - these things cook if not properly cared for or run at highway speeds for hours on end. check the oil, is it black? does it have a great deal of dust in it after driving (bronze from the bushings). Does it get stuck in gear after a highway run ? does it shift really hard when hot? excessive noise in 5th gear ? I have changed 11 gearboxes and I swear each one is the last time for me.
clutch, common issue. These trucks love to throw one of the three clutch arms. This is generally a random ocurrance when one of the ears on the rear of the arm fails and the arm breaks off. How can you tell? take up the center section of the floor and look at the inspection port on the bellhousing, take off the two bolts, contort you body and use a small light to inspect the arms, does the ring at the center look level from all three or does it tilt? if it tilts it may need a new arm. Not the end of the world and if you are flexible you can replace in-situ. Not easy though.
Fuel system - look for leaking carbs (they all leak) but if it is dumping gas onto the lower carb plate then you are looking at a rebuild at least (not terribly expensive but time consuming)
Check the differentials - are they over-filled ? any evidence of oil spillage on the top near the vents ? if so chances are the torque tubes are leaking oil from the gearbox down into the diffs or sometimes vice versa. Can be bad for the gearbox as it means it could have starved for oil. check hubs as well for oil level. This is a common problem, my trucks will seep, leak, splash oil for the first month I run them I just check the oil levels very regularly to ensure I am not starving a diff or the gearbox or hubs for oil. The seals are paper or fiber and usually swell back up with use.
The rear seals on these engines leak like it is their job - every M180 engined car, truck I have had does this. unless it is really bad it is usually not a major concern.
there are many things you should look for but these come to mind.
The 404 is out of production nearly 30 plus years now and has not been in service for at least 25 years at least, I started buying them in 1999 and at that time they were about 900 for a decent model, now finding one in Europe that is clean under 6,000 EURO is rare. If the price is right and you can turn a wrench (mostly simple work) then it may be worth your time. Feel free to PM me and I am happy to share what I have found and what pitfalls I have had. Good luck