OVM,
Congrats on logging that relatively trouble-free 400K miles - well done ! May your next 400K be equally as trouble-free.
You are a little short on the transmission fluid changes (the recommendation was revised to every 60K miles) - but as your experience shows it possible to go longer with no adverse effects. When I sent my ATF to Blackstone to have it analyzed at my first service (62K) their analysis said that it could have been run longer (this of course may vary from vehicle to vehicle, based on conditions) To some extent, this may show why M-B was inclined initially to recommend that the transmission be serviced
only once at 80K miles ....
Particularly impressive on the belt tensioner ... have you replaced the other idler pulleys ?
All the rest of the stuff is surely normal maintenance, other than the turbo resonators - curious as to why you never replaced that with the turbo resonator eliminator, as it would have allowed you to avoid any limp-home mode episodes and replacements in the future ......
Myself, I have done normal routine maintenance (fluids/filters), the vehicle is currently at 187K miles, and other than the normal maintenance, the only other problems I have had are:
1. air intake temperature sensor replaced at 1.5K miles (warranty),
2. rack and pinion replaced at 4.5K miles due to an internal leak (my fault for hitting a curb with the wheels at full lock, but replaced under warranty),
3. lumber support in seat (my fault again, for squeezing the bulb too hard (warranty),
4. replaced serpentine belt at 123K miles, (cracked, but still functional)
5. replaced both idler pulleys at 175K miles (bearing dry on both, noisy on the one)
6. front brakes and passenger side front wheel bearings at 175K (probably could have avoided the bearings - they weren't really all that bad and really could have still gone longer, but I didn't want to chance a failure on the road - had I pulled the wheels and repacked the bearings at 100K miles, and adjusted the bearing end play to spec),
7. One glow plug failed (shorted to ground) at around 165K miles.
8. Glow module/relay .... unfortunately this component is of a questionable/poor design: when a glow plug fails it can fail one of two ways - either A. shorted open or, B. shorted to ground. When it's B, then the individual circuit in the module (there are 5, one for each glow plug) is also destroyed and it will cause the check engine light to come on intermittently. This flaw in the design argues for periodic replacement of the glow plugs particularly when one glow plug has failed ..... to avoid also ruining the module multiple times. (glow plugs - $20 each, module - $90 to $120)
9. Apparent failure of the connector plate (which houses the speed sensors) on the valvebody in the transmission .... this may not have actually been a failure - but merely a ferrous metal contamination issue: the internal speed sensors in the transmission are very strong magnets, and are prone to attracting the minute ferrous metal debris that is worn off various components. When they become covered in ferrous metal debris, they are prone to causing all manner of erratic behavior (becoming stuck in a particular gear, etc.), will cause the vehicle throw DTC's and may put the vehicle in permanent limp-home mode.
In my particular case, the vehicle became stuck in gear a number of times over several months (resolvable by cycling the vehicle off and then back on), but eventually became stuck in permanent limp-home mode (while I was on a load
), and that required a trip to the dealer and resetting with the DRB-III scan tool. The actual error codes had to do with an implausible value (>8000 rpm) for the input shaft speed that one specific speed sensor (the N3) was reporting.
It's possible that I could have resolved the problem by cleaning the ferrous metal debris that I found off the speed sensors - but I was unwilling to take the chance that there might actually be something wrong other than that with the assembly, and the part was only $180 so I went ahead and replaced it.
It's also possible that had I gone to a dealer who was ill-informed, untrained, or unscrupulous, that the recommendation would have been to replace the entire transmission for mucho bucks.
TJ, the key to glow plug removal is using great care (controlled, but not excessive force - I used a 1/4 drive breaker bar - which is about 5" long - not much leverage there) and (this part is
critical) having the engine
hot - I used a blanket over the radiator/grill and high-idled the vehicle (which was already at operating temperature) for about 10 minutes @ 2000 rpm, which elevated the coolant temp. This is something that is best done on a hot summer day for obvious reasons.
Work fast (the head is aluminum and will cool rapidly), removing and replacing one glow plug at a time - so that you can restart the vehicle and warm it back up to do the next one.
