Motor Mount Bolt-HELP! - Page 2 - PeachParts Mercedes-Benz Forum

glenmore · #16 08-05-2011, 01:12 PM

No. Loosen both top mount bolts and remove the top bolt on the side you are going to start with. Then remove both bottom mount bolts. Raise engine slowly. It will seem like you are raising it a lot. A new mount is probable about 1/2" taller than your old mount and you need wiggle room. Raise until you can get the old mount out. Sweep the grit out the seat of the crossmember. Try the new mount. It won't fit. Raise until you can get it in there. Put the top bolt in finger tight. Do the same for the other side. Start the lower bolts and slowly lower engine and make sure the mounts seat onto the cross member.

EricSilver · #17 08-05-2011, 01:45 PM

Quote:

Originally Posted by glenmore

No. Loosen both top mount bolts and remove the top bolt on the side you are going to start with. Then remove both bottom mount bolts. Raise engine slowly. It will seem like you are raising it a lot. A new mount is probable about 1/2" taller than your old mount and you need wiggle room. Raise until you can get the old mount out. Sweep the grit out the seat of the crossmember. Try the new mount. It won't fit. Raise until you can get it in there. Put the top bolt in finger tight. Do the same for the other side. Start the lower bolts and slowly lower engine and make sure the mounts seat onto the cross member.

OK:
* Loosen both 17mm top bolts [one per mount]
* Remove top bolt from the mount I am working on
* Remove both bottom (17mm?) bolts [one per mount]
* Raise engine until old mount(s) can be pulled out
* Raise engine further to install new mounts
* Replace top bolts and hand-tighten
* Thread lower bolts through cross member and into bottom of new mounts
* Lower engine, assuring proper mount seat into cross member
* Tighten upper and lower bolts
//done

I will also be replacing my steering damper while the car is on the jacks. Any precautions?

glenmore · #18 08-05-2011, 02:16 PM

Looks good.

Remember the fan shroud.

The bottom mount bolts are IIRC 8mm allens.

If your car is doing that rough idling in gear, you'll be amazed at the difference with the new mounts.

You might as well do the tranny mount if that hasn't been done in awhile. Just unbolt and bolt new one in with the tranny supported.

Steering damper is routine.

deanyel · #19 08-05-2011, 02:18 PM

You raise the engine before tackling the upper bolts - creates lots more room to work. Here's my routine, slightly modified from my E420 notes:

Remove fan shroud – 3 8mm bolts, 2 clips (E420)
Raise all 4 tires on 6 inch blocks or ramps
Remove lower MM bolts – 13mm, 8" extension
Jack up engine at pan
Remove top bolts, 17mm (lever on wrench from top)
Remove MM/shields / install new MM
Install lower bolts loosely, with blue loctite
Lower engine partially until top bolts can be installed
Lower engine more – tighten top and bottom bolts
Lower engine all the way
Tighten upper bolts to 40 ft. lbs. (E420)
Tighten lower bolts to 18 ft lbs (E420)
Re-secure fan shroud

The reason I raise all four wheels to start is because it makes the engine lift less exciting. If you raise only the front wheels on blocks/ramps, and then jack the engine it creates quite an angle for the jack under the oil pan. Flatter seems safer.

Remember some of this is 420 specific. On the 420 driver side you have to remove a piece of exhaust pipe to get the mount out of the engine compartment.

EricSilver · #20 08-05-2011, 02:30 PM

Quote:

Originally Posted by glenmore

Looks good.
The bottom mount bolts are IIRC 8mm allens.

Why do i suspect that will be where I hit my inevitable obstacle(s).

Quote:

Originally Posted by glenmore

If your car is doing that rough idling in gear, you'll be amazed at the difference with the new mounts.

It's beyond rough;two weeks ago I replaced my center muffler, which was cracked. The engine's restored back-pressure is now causing extremely heavy vibration.

glenmore · #21 08-05-2011, 02:34 PM

[QUOTE=EricSilver;2764514]Why do i suspect that will be where I hit my inevitable obstacle(s).

You should have those in your tool box! I like fancy tools as much as the next guy, but cheap ones from AutoZone or PepBoys are fine.

EricSilver · #22 08-05-2011, 02:41 PM

Quote:

Originally Posted by deanyel

You raise the engine before tackling the upper bolts - creates lots more room to work.

The reason I raise all four wheels to start is because it makes the engine lift less exciting. If you raise only the front wheels on blocks/ramps, and then jack the engine it creates quite an angle for the jack under the oil pan. Flatter seems safer.

OK on raising engine first.

And that's a good point about the angled jack - especially considering the wheeled floor jack I plan to use to lift the engine.

glenmore · #23 08-05-2011, 02:41 PM

You can do it!

I am just your average knucklehead and I have done it 4 times. Twice with a W124, once with a W202 and once with a Lexus LS400. I do have a pretty good box of tools though.

The Mercedes were a 100 times simpler than the Lexus!

EricSilver · #24 08-05-2011, 02:44 PM

[QUOTE=glenmore;2764519]

Quote:

Originally Posted by EricSilver

Why do i suspect that will be where I hit my inevitable obstacle(s).

You should have those in your tool box! I like fancy tools as much as the next guy, but cheap ones from AutoZone or PepBoys are fine.

The 6mm allens that used to secure my water pump were designed by Satan himself. The 8mm, hopefully, will not be as bad but I will buy a few ahead of time nonetheless.

glenmore · #25 08-05-2011, 02:55 PM

OK, I take that back. Cheap tools are OK for mundane stuff. But if you have something somewhat critical, use Snap-On!

If you did a M104 water pump, this is a breeze.

EricSilver · #26 08-05-2011, 03:05 PM

Oh, I am not worried about the tools or the challenge; there is always that one unforeseen "gotcha" that makes a simple job complicated. With me it is often bolt-related so I'll be preparing for that.

EricSilver · #27 08-08-2011, 11:45 AM

On paper, for a late-1995 E320, this is a very simple job. There are 4, 17mm hex-head bolts (10mm bolts size, 1.50 thread pitch, 25mm length) to be removed. The mounts sit directly on the cross member secured by one bolt on top and one on the bottom. Remove bolts, jack the engine up, swap out the mounts, align mounts correctly, replace bolts, lower engine, tighten bolts, and you’re done. That is the full scope of the job. On paper.

Driver’s Side
Contrary to what I read, the driver’s side was the easiest to work with. Standing in front of the headlight, it is possible to insert your arm under the intake and place a ratchet onto the top bolt. A firm twist of the wrist was all that was required to loosen it. The bottom also came loose easily with the help of a 2-foot pipe extension on the ratchet handle.
Simple, right? Wrong!

The smile on my face, after so easily doing this side, was instantly erased when the bottom bolt dropped into the hollows of the cross member, irretrievable, and never to be seen again. But I’ll get back to this.

Passenger Side
Unless you are a professional arm wrestler, you will probably not loosen the top bolt with just a wrench. After removing the air cleaner cover and the flex pipe to give myself room, I secured a 17mm universal wrench to the top bolt, then inserted my 24” pipe section into the space behind the air cleaner and down to the visible portion of the steering linkage – with the upward surface of the pipe against the linkage and the downward surface against the wrench handle. Holding the wrench firm in one hand, I pulled the pipe towards me and the bolt cracked free. The bottom bolt on this side required no more force than the driver’s side – and there were no hollows for it to fall into.

Engine Jacking
If you have one of those $30.00 floor jacks with a 15” rise, you will need two 2x6 pieces of lumber. A single piece will raise the engine high enough to remove the collapsed mounts, but not high enough to insert the new ones.

Lost Bolt Contingency
It is a good idea to have at least 4 spare bolts, of the size I described above, standing by in case you need them. I’m sure dealer would be happy to charge you $6 each but you could get 8.8 or higher grade from hardware stores for about a dollar. Also, I bought 30mm lengths instead of 25mm; however, the threads in the mount are deeper than that so, with thicker washer offset, I don’t see a problem. (But feel free to correct me if I am wrong.)

After losing the driver-side bottom bolt, I secured the upper bolt in its place and swapped over the passenger-side top. Right now, the passenger side has just the bottom in place, with a discarded 6mm "place keeper" bolt helping keep the top opening from becoming too misaligned, until I install the proper replacement later today.

Mount Brands
I ordered without regard to brand, which in my case was Hamburg Technic. After Googling, I saw that it is a solid rubber mount that most people don’t like. As far as vibration dampening goes, it does a good enough job, but probably not as good as a gel/liquid core mount. So I have a feeling I will be doing this job again at some point.

Trivia
While you are doing this job it is easy to replace your steering damper. My old one made hissing, wet-fart noises when I removed it. Now, my steering is again solid, and not reacting to every road contour.

If you try to start the car with the air intake cover and flex pipe removed even with the MAF still connected -- it will crank and shut down exactly as it would if a crank sensor failed. (Or is that just me?)

glenmore · #28 08-10-2011, 12:18 PM

Every time I drop a screw, I curse my cheapness for not just going ahead and buying this tool.