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Lowering Front Sub Frame to replace Engine Mounts??
HI All,
Looking at replacing engine mounts on my wife E350 (Australian) wagon and come across this on YouTube which looks so much easier than trying to remove exhausts and steering racks.
Replaced the engine and trans mount using the above method and must say although I was stressed unbolting the sub frame from the car it actually was pretty straight forward.
Some things to look out for are make sure you disconnect the little electronic actuator that is connected to the sway bar and the electrical connection that goes to the steering sensor otherwise you will damage them when lowering the engine/sub frame to remove the mounts from the bottom. Also be aware of the strain you put on the AC lines above and disconnect the vacuum line from the firewall that goes to the brake booster, make sure you disconnect the battery and remove the top engine covers including the air box.
It's also handy to have a 16mm long flexible head ratchet spanner, as per video above, but I managed with a fixed head ratchet but was a bit of a struggle.
Wow... too risky for me based on all you mentioned and if the jack supporting the engine failed. Uncle Murphy is always something I worry about.
My indie remove my exhaust system, that is all and it is simple. My engine has turbos, so it would be a bit more complicated than regular M276 3.5 NA
Wow... too risky for me based on all you mentioned and if the jack supporting the engine failed. Uncle Murphy is always something I worry about.
Uncle Murphy is always watching.
Wonder if longer bolts for the sub-frame can be sourced. Then, I would use those and always have the sub-frame secured with loose bolts just in case Murphy shows up (the sub-frame could only slide along the bolts)
Yes I was worried about that but the sub frame is supported by the suspension and can't fall from where it stops which is about 50mm (2 inches) which gives you ample room to work. The trick is getting the sub frame up into position to bolt it back, as i was already using my jack to support the engine so I used a motorbike lift to raise the sub frame into position to be able to bolt it. A second jack would help.
Yes I was worried about that but the sub frame is supported by the suspension and can't fall from where it stops which is about 50mm (2 inches) which gives you ample room to work. The trick is getting the sub frame up into position to bolt it back, as i was already using my jack to support the engine so I used a motorbike lift to raise the sub frame into position to be able to bolt it. A second jack would help.
Definitely safe, but a bit of a risk if there is a misalignment. Then, the idea of longer bolts helps on guiding it back in place.
If using longer bolts, the process is replacing 1 by 1; therefore, the subframe is NEVER misaligned and safely secured by the suspension (great point). Then, there is only a need to push back up along the long bolts, replace 1 by 1 the original ones, and torque them up to specs.
Replaced the engine and trans mount using the above method and must say although I was stressed unbolting the sub frame from the car it actually was pretty straight forward. Some things to look out for are make sure you disconnect the little electronic actuator that is connected to the sway bar and the electrical connection that goes to the steering sensor otherwise you will damage them when lowering the engine/sub frame to remove the mounts from the bottom. Also be aware of the strain you put on the AC lines above and disconnect the vacuum line from the firewall that goes to the brake booster, make sure you disconnect the battery and remove the top engine covers including the air box. It's also handy to have a 16mm long flexible head ratchet spanner, as per video above, but I managed with a fixed head ratchet but was a bit of a struggle.
John
John, thank you for the great advise. I saw the same video and been thinking about tackling with it a week now, just waiting for the weather to warm up a little because I`ll do it on the driveway, garage is full of wife`s crap lol.
I`ll try to take pics or maybe a video and post it here, of course it depends on the frustration level.
Cheers
Al
I have a 4Matic and planning to do this soon, just waiting for the weather to pick up a little. Probably within a month. I`ll try to post pics maybe a video.
The white car in the video looks like a 4matic but I only watched it once, will pay attention next time. Honestly, it was a little dizzying, he kept moving the camera back and forth too fast, he was all over the place, but overall still a helpful video.
I have a 4Matic and planning to do this soon, just waiting for the weather to pick up a little. Probably within a month. I`ll try to post pics maybe a video.
The white car in the video looks like a 4matic but I only watched it once, will pay attention next time. Honestly, it was a little dizzying, he kept moving the camera back and forth too fast, he was all over the place, but overall still a helpful video.
There are some shots near the end that I would have expected to see half shafts coming out of the oil pan if it were a 4matic.
@jltarra Thank you for the great advice and information. I was going to not do this but I think I will take another look at it. What size bolts are the sub-frame bolted with and the length. As @juanmor40 suggested that seems like a good idea. I am willing to do the research into a longer bolt to use with this idea and report back. BTW do you think after doing this that it is the only way for it to be done.
Thank you. BTW what is the best way to tell if you actually need to replace the engine mounts and the transmission mounts. I happen to have the car in the dealership for something and they said I needed them. How do they tell. I am not trusting them completely as they have said something needed replacing and it did not at the time.
1 - The car MUST feel firm on the road when stepping (not to the floor) on the gas, and if you feel the transmission kind of kicks/rough shift from 1st->2nd or 2nd->3rd (depending of the initial speed you had it in) the mounts are likely worn by then.
2 - Others check it by using both feet, one on the brake pedal pressed, and the other on the gas check if the engine rotates/rises when you slightly press the gas. Not easy since you need two people, and I do not want to be in front of the car.
3 - Visually inspect them, but you need to know (have seen) the original distance between bottom->top of the mount. When worn the collapse, so the distance is reduced. It is much so, the gap between lower engine components and surrounding changes significantly. Recall those gaps are small in these engines. Picture for the R129 (from internet), but you get the idea
4 - The transmission mount usually collapses (video for W211)
I was having those symptoms back at @45K miles (late 2018), and I thought to do the transmission service and not wait longer and the dealership checked the issue. When I picked up the car, there was no charge for transmission service, and they changed the 3 mounts at no charge then. The car drove like new, and I realized I had forgotten how it used to be and got used to the kick/rough shift. Now @92K, and they seem fine to me, no kicks/rough shift when accelerating.
Thanks for the information. I will check these things. Nice that you had no charge. I think I was quoted by the dealership about $1800 (1320+ and $440) for the engine and transmission mounts.
I would like to do it myself too in my home garage. I like you have to be mindful of my back. I live in AZ so will likely do it when needed (not in the summer). Garage gets hot. The challenge if I do not do it is finding an honest independent - very difficult.
I would like to do it myself too in my home garage. I like you have to be mindful of my back. I live in AZ so will likely do it when needed (not in the summer). Garage gets hot. The challenge if I do not do it is finding an honest independent - very difficult.
Where in AZ? @konigstiger (the master) works in Scottdale, and perhaps he can recommend someone around the area.
I live in Mesa which is close to Scottsdale. Does @konigstiger work as a technician? If not a recommendation would be great. I do not mind driving, if necessary for a great technician (independent).
Last edited by MPTrader; May 17, 2023 at 01:55 PM.
Brother if you've got the M276 all you need is a long extension and a 16mm Wobble Socket. Once you remove all the shielding and airboxes, you can fit a 16mm universal socket onto the bolt atop the engine mount and just spin it off with an impact. You've got the right idea with a ratcheting flex head, but I find the most time efficient method is to get a 16inch+ impact extension, 16mm impact wobble socket, and I use a breaker bar then zip it out. I use cheap harbor freight lifetime warranty sockets idc about breaking too.
Thanks for the info. I'm thinking the top should not be too bad. It is the bottom and actually getting the mounts out that will take more effort but doable. Would be great if they could easily slide out and back in once unbolted. But the nature of the part does not lend to that.
Thanks for the info. I'm thinking the top should not be too bad. It is the bottom and actually getting the mounts out that will take more effort but doable. Would be great if they could easily slide out and back in once unbolted. But the nature of the part does not lend to that.
Brother, also dont forget you can come from behind the wheel well! You may still have to unbolt some suspension components but you're not dropping the Sub frame so you've gotta do your own cost benefit analysis.
I was able to slip the mount out with some minor manipulation of the part. Inasmuch as you solve this puzzle in the video is how I slid the mount out!
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Uncle Murphy is always watching.
