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Tranny & Engine mounts, the consumable comfort component
Gents,
For those who is lacking of sensitivity towards vibration caused by engine mounts and/or tranny mounts already sinking too deep, or bought the car pre-owned and assume whatever it does "today"
is the norm..... I am showing you some visuals to help you guys make your car more comfy.
Easiest to see is tranny mount. A mirror can help, or a boroscope.
When I bought the car pre-owned, in May 2018. By August 2018 I reset the mounts, all 3 replaced.
Unloaded visual, using tranny mount mounting holes as reference to the sinking of the mount.
Unloaded, side my side.
.
The then new one in Oct 2020, by today 15,500KM later or car mileage 39,500KM as per 25 March 2024
As per my previous calculation, I would say that maximum 25,000KM of use for best comfort will still be my target.
Below LEFT is a Youtube sample of a guaranteed "kissing" mount to its bottom side when loaded with tranny weight. So vibration is guaranteed.
The RIGHT side is my very 1st mount original to the car, when it was replaced on 15th Aug 2018.
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Engine mounts
The black rubber flap should never ever touch the mount raise body. That is a fail already.
Example as per my link below, my friend's W204 mount already vibrating the engine like a junk car. https://mbworld.org/forums/e-class-w...tear-down.html
........
My LEFT side, also 10,500 KM driven, same as RIGHT side one.
.
Engine mounts is good comfy to 25,000 KM too for me. I am hyper sensitive to "vibrations".
My roads are bad.
My driving is HARD, kick down and WOT red line often.
Also my highway bridges joints are bad, even my rear suspension can bottom out. This put stress on all 3 mounts too.
There is no speed limit per-se in my country ....it is easily forgiven if not forgotten.
So, take a peek under you car, inspect those 3 mounts and enjoy a more comfy ride...............
When all 3 mounts are new, reset your azz-dyno.... that is reference point of a good set of mounts.
You'll get about 4 years out of the motor and tranny mounts before you'll start to feel that slight vibration at idle again. I babied mine, I am a very smooth and easy driver. Replaced my mounts in summer 2019 at 40k miles. Was getting an awful sound on the frame of the car when shifting 4th to 5th for a split second. Transmission mount was toast and metal on metal contact for a quick second. Car was solid, smooth and quiet after the two motor mounts and trans mount were replaced. Sold it recently at 73k miles-ish and was starting to notice that all too familiar feeling again, slight vibration at idle and in gear. Not bad, certainly not really noticeable except to someone like me who knew what it felt like when they were new. Got 4 years out of them and roughly 32k miles, mostly all highway cruising. Probably had another 12 months and 10k miles to go before becoming obvious to pretty much any driver who's ever had a nice smooth sedan before.
Also learned a valuable lesson with MB in general. My next one, if it's a sedan, won't be 4matic. RWD only for me now. Changing the motor mounts in a RWD 212 vs an AWD 212 is notably difference and far easier in the RWD.
Yeah, this is the first thing I do and tell everyone to do who buys a used car that's more than about 5 years old. The cutoff for older Benzes used to be about 10 years, but they apparently don't make rubber like they used to anymore. I have rubber and plastic parts on an '88 Porsche that are still fine. Some are completely trashed obviously, but that is to be expected on an almost 40 year old car that was stored in a field for a while and got overgrown by vines... You would think with advancing technology that we would be using better and better rubber (technology has been advancing, and there do exist better and better rubbers all the time), but instead we actually get worse rubber parts over time. I don't think it's entirely cost based either. Environmental restrictions are putting more and more limitations on the precursors and production processes used to make plastics and rubbers for cars. There are even some materials which are already set by regulators to be phased out in the near future for which there are no suitable replacements...
But I digress. I agree--replace your rubber often.
Yeah, this is the first thing I do and tell everyone to do who buys a used car that's more than about 5 years old. The cutoff for older Benzes used to be about 10 years, but they apparently don't make rubber like they used to anymore. I have rubber and plastic parts on an '88 Porsche that are still fine. Some are completely trashed obviously, but that is to be expected on an almost 40 year old car that was stored in a field for a while and got overgrown by vines... You would think with advancing technology that we would be using better and better rubber (technology has been advancing, and there do exist better and better rubbers all the time), but instead we actually get worse rubber parts over time. I don't think it's entirely cost based either. Environmental restrictions are putting more and more limitations on the precursors and production processes used to make plastics and rubbers for cars. There are even some materials which are already set by regulators to be phased out in the near future for which there are no suitable replacements...
But I digress. I agree--replace your rubber often.
Nothing is built to last it seems anymore. Especially appliances. In the last 8 years, we’re on our 3rd washer/dryer, second dishwasher, second refrigerator, repaired double oven, and second microwave. Apple and Bose are about the only two brands that seem to last for us.
You'll get about 4 years out of the motor and tranny mounts before you'll start to feel that slight vibration at idle again. I babied mine, I am a very smooth and easy driver. Replaced my mounts in summer 2019 at 40k miles. Was getting an awful sound on the frame of the car when shifting 4th to 5th for a split second. Transmission mount was toast and metal on metal contact for a quick second.Car was solid, smooth and quiet after the two motor mounts and trans mount were replaced. Sold it recently at 73k miles-ish and was starting to notice that all too familiar feeling again, slight vibration at idle and in gear. Not bad, certainly not really noticeable except to someone like me who knew what it felt like when they were new. Got 4 years out of them and roughly 32k miles, mostly all highway cruising. Probably had another 12 months and 10k miles to go before becoming obvious to pretty much any driver who's ever had a nice smooth sedan before.
Also learned a valuable lesson with MB in general. My next one, if it's a sedan, won't be 4matic. RWD only for me now. Changing the motor mounts in a RWD 212 vs an AWD 212 is notably difference and far easier in the RWD.
40K miles a goner, thus for your kinder-than-me use profile the best comfy probably would fall within 30K miles max, or 48,000KM.
That is a lot of distance if it were for my use case
Since the 3 mounts does its job so well, I can't be too pissed with its peak-comfy short service life.
I have front wheel drive cars I drive much harder, by 25,000KM the mounts will "knock" ( must be bottoming out ) upon fast gear change 1 to 2 or aggressive 1st gear clutch release. A manual tranny.
FWD eat mounts faster if apple to apple to a RWD car.
Those FWD cars are probably not Mercedes. "Lesser" cars have crap rubber mountings from the factory and suck from day 1. In the past, Mercedes had amazing rubber parts that were comfy and still did their job for much longer than 30k miles (~3 years?). 10 years or 100k miles is what we used to get--even on shocks. By W211 times, shocks went down to about 60k miles, now I'm not sure what we're at now on the W212... Mine seem to be OK-ish, but I will definitely replace them soon. They've probably been replaced before.
Granted, cars had way less torquey engines than now (compared to back in say W123 days), but engine and tranny mounts have also gotten bigger to compensate. And this doesn't affect shocks too much, although the entire car is heavier so that comes into play...
I'm not complaining--I knew what I signed up for getting this car. I wanted the car with all the goods and bads of modernity that were totally expected. I'm about to rip half my engine bay apart this weekend to replace a tiny buried piece of plastic that obviously wasn't meant to be serviced, yet wasn't designed to last more than 10 years. (There is a stress riser designed into the part at the base of a long lever arm which has a vibrating hose attached to it. This, combined with crappy plastic and temperature cycling just looks like a total oversight.) Nevertheless, totally worth it.
Last edited by ChuangTzu; Mar 28, 2024 at 12:36 AM.
Yep... PLASTIC at engine bay for coolant or vacuum and for some engine ( M271 EVO ) for hot oil....... will be our enemy
If your tranny oil cooler is a combo with your main radiator ( also plastic at the sides ) , the rubber seal inside will fail and you can't replace them (2 pcs ) anyway, so the whole radiator must go if you
want to avoid tranny oil mixed with coolant killing tranny.
I think if M278 engine, it has stand alone tranny oil cooler like my M276 3.0 Turbo
Must see EPC and car VIN to be sure
An M278 has 2 coolant+oil seal as time bomb which serve as cross-over seal between engine block via/crossing timing chain region and then to coolant circ pump and oil cooler.
My M276 3.0 turbo has similar time bomb too, but 2 round seal/o-ring only. M278 has a molded seal and 1 round o-ring. The molded seal is the weaker one, this is for oil cooler.
If these 2 seals leak, coolant enter timing chain oil bath region and cocktail you get.
These turbo engines are unlike older NA engines. These run hot and has so much more power.
Is it harder to replace the Transmission mount on the 7G 4-Matic version?
I just did mine this week, and it was quite easy! I mean, it has more fasteners than my RWD c207, but the principal is the same….lift car, support/raise transmission slightly/safely, swap out part, torque fasteners, done! Much improved ride
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
....it is easily forgiven if not forgotten.
, it has M278 as case study and its TSB
