Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 11-18-2013, 10:31 PM
Registered User
 
Join Date: Nov 2013
Location: northern georgia
Posts: 16
engine mounts on a 300sd

i ordered 2 new engine mounts for my 1985 300sd
1) how far down should they compress with the weight of the engine on them?
2) if i fill them with polyurethane how much should i fill them? should i allow for compression?
3) i see guys on youtube using 3M window weld, will this work in this application? I live in the boonies n i need to get my car back up in running asap n there is only a Homedepot n a ace here in town......
4) If the 3M will work on the engine mounts , will it also work to replace the bushings on the engine shocks?

Reply With Quote
  #2  
Old 11-18-2013, 11:54 PM
Registered User
 
Join Date: Sep 2012
Location: Wilmington, NC by the Atlantic ocean
Posts: 2,509
Those engine mounts are calibrated for your OM617. I'd use them as they are. The rubber in any motor mount is vulcanized in place and cannot be replaced using any home methods. The vulcanizing process is what bonds the mount to the metal parts. If you had access to vulcanizing equipment you could do that but few of us have those skills and equipment.

As far as the engine shocks - they aren't all that pricey so I'd order up a set. I'm not using them on the S-10 but it's race only and I don't mind if it's a bit "course". On a nice 300SD they're probably dead anyhow and need replaced - this is the time to do it. They'll come with new rubbers.

Dan
Reply With Quote
  #3  
Old 11-19-2013, 01:18 AM
mach4's Avatar
Registered User
 
Join Date: Jul 2011
Location: San Diego County, CA
Posts: 2,736
Quote:
Originally Posted by Trudge View Post
i ordered 2 new engine mounts for my 1985 300sd
1) how far down should they compress with the weight of the engine on them?
2) if i fill them with polyurethane how much should i fill them? should i allow for compression?
3) i see guys on youtube using 3M window weld, will this work in this application? I live in the boonies n i need to get my car back up in running asap...
I'd estimate about 1/4 inch, but I never actually measured. The window weld might work, but if it's too hard you'll get unpleasant vibration.

Fill them all the way up with a Shore A 30 urethane and you'll be fine.

__________________
Current Stable
  • 380SL (diesel)
  • Corvette C5
  • Manx
  • Baja Bug
  • F350 Powerstroke
  • Auburn Boattail Speedster replica
Reply With Quote
  #4  
Old 11-19-2013, 01:30 AM
vstech's Avatar
DD MOD, HVAC,MCP,Mac,GMAC
 
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 26,389
Quote:
Originally Posted by Dan Stokes View Post
As far as the engine shocks - they aren't all that pricey so I'd order up a set. I'm not using them on the S-10 but it's race only and I don't mind if it's a bit "course". On a nice 300SD they're probably dead anyhow and need replaced - this is the time to do it. They'll come with new rubbers.

Dan
he's not talking about the shocks, he's talking about the shock mount... and it's pricey... if a pullapart junkyard is not available I'd recommend a pair of fender washers to fix the mount. Roy is trying to rebuild the mounts, he wants broken parts to experiment on...
__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!
Reply With Quote
  #5  
Old 11-19-2013, 02:08 AM
Zacharias's Avatar
Not so amused
 
Join Date: Apr 2010
Location: West Quebec
Posts: 4,025
Quote:
Originally Posted by mach4 View Post
I'd estimate about 1/4 inch, but I never actually measured. The window weld might work, but if it's too hard you'll get unpleasant vibration.

Fill them all the way up with a Shore A 30 urethane and you'll be fine.
Someone had suggested to me a product called Liquid Nails, usually available at local hardware or home improvement stores. When I checked the manufacturer website, it claims to be Shore 30.

However, my impression has been that this discussion really has been around cheap motor mounts. If you bought a quality brand like Lemfoerder or Phoneix or Corteco, I would not bother with filling them.

Of course if you're like me, and bought a set of Anchors at under $4 from the Rock (for 617 NA), just for poops and giggles, then yeah....
__________________


Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22
Reply With Quote
  #6  
Old 11-19-2013, 10:17 AM
Registered User
 
Join Date: Sep 2012
Location: Wilmington, NC by the Atlantic ocean
Posts: 2,509
Quote:
Originally Posted by vstech View Post
he's not talking about the shocks, he's talking about the shock mount... and it's pricey... if a pullapart junkyard is not available I'd recommend a pair of fender washers to fix the mount. Roy is trying to rebuild the mounts, he wants broken parts to experiment on...
I think I tossed my old ones or I'd donate them. I had two sets. I don't see what good filling the base of the mounts would do except making the whole deal a bit stiffer, which would not be better.

I'm not above messing with factory stuff but I don't see where you'll gain anything with this technique. My new mounts were a donation so I don't know what they cost but it wasn't much. If they fail I'll just replace them with more cheap mounts!

Dan
Reply With Quote
  #7  
Old 11-19-2013, 11:32 AM
Registered User
 
Join Date: Nov 2013
Location: northern georgia
Posts: 16
I'm using Lemfoerder engine mounts . I replaced them in July ones all ready with a donated pair n the driver side is shot all ready ...... Side note The kid i bought the car frome had driven the car so long with a destroyed driver side mount that it blew out the engine shock mounts rubber AND BLEW A HOLE IN THE K MEMBER ...... So ill b patching the k member with 1/8 plate steal unless someone has a better idea . N ill do something cheap for the shock mount ........the car is my salt driver n I just need it to last as best possible
Reply With Quote
  #8  
Old 11-19-2013, 11:34 AM
mach4's Avatar
Registered User
 
Join Date: Jul 2011
Location: San Diego County, CA
Posts: 2,736
Quote:
Originally Posted by Dan Stokes View Post
I don't see what good filling the base of the mounts would do except making the whole deal a bit stiffer, which would not be better.

I'm not above messing with factory stuff but I don't see where you'll gain anything with this technique.
The back story on the filled mounts is that when I swapped an OM617 into my 380SL I had less than optimal clearance between the engine and the subframe. Having read all the horror stories about the poor quality of currently available motor mounts, I searched for a solution that would give me insurance against a collapsed mount somewhere inconvenient (like in the middle of nowhere on one of my cross country road trips) The solution I came up with was the filled mount. Most motor mounts are just a slab of rubber between two metal mounting surfaces, so making the stock MB mount into what is essentially functionally equivalent is not a stretch.

The process showed that a stiff urethane (70) will indeed make things very harsh, but the softer Shore A 30 is essentially indistinguishable from stock.

So if someone is looking for cheap insurance or to extend the replacement interval or to be able to use cheaper mounts in the first place or has a custom application, the filled mounts are an option to consider.

I also fillers my subframe mounts to prevent those from collapsing as the clearance between my valve cover and hood is very tight as well and would result in contact.
__________________
Current Stable
  • 380SL (diesel)
  • Corvette C5
  • Manx
  • Baja Bug
  • F350 Powerstroke
  • Auburn Boattail Speedster replica
Reply With Quote
  #9  
Old 11-19-2013, 11:53 AM
mach4's Avatar
Registered User
 
Join Date: Jul 2011
Location: San Diego County, CA
Posts: 2,736
Quote:
Originally Posted by Zacharias View Post
Someone had suggested to me a product called Liquid Nails, usually available at local hardware or home improvement stores. When I checked the manufacturer website, it claims to be Shore 30.
Which product were you looking at? The regular LiquidNails adhesive is latex based. The Polyurethane Construction product showed a Shore 60 rating.

The one concern I'd have about using this kind of product for something as thick as a motor mount would be the curing. The stuff I used was a two part mix while this product relies on moisture from the air to cure. Thin applications as caulk, might be completely different from filling an inch-thick void... I just don't know.
__________________
Current Stable
  • 380SL (diesel)
  • Corvette C5
  • Manx
  • Baja Bug
  • F350 Powerstroke
  • Auburn Boattail Speedster replica
Reply With Quote
  #10  
Old 11-19-2013, 12:06 PM
Zacharias's Avatar
Not so amused
 
Join Date: Apr 2010
Location: West Quebec
Posts: 4,025
Quote:
Originally Posted by mach4 View Post
Which product were you looking at? The regular LiquidNails adhesive is latex based. The Polyurethane Construction product showed a Shore 60 rating.
Good question. I just looked again and I see what you mean, there are three varieties of LN but all are over Shore 30.

I will check later when I have more time, to see what I was looking at.
__________________


Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22
Reply With Quote
  #11  
Old 11-19-2013, 02:35 PM
Registered User
 
Join Date: Nov 2013
Location: northern georgia
Posts: 16
How far down will the mount compress with the weight of the engine on it ? I don't want to over fill it .
Reply With Quote
  #12  
Old 11-19-2013, 02:40 PM
mach4's Avatar
Registered User
 
Join Date: Jul 2011
Location: San Diego County, CA
Posts: 2,736
Quote:
Originally Posted by Trudge View Post
How far down will the mount compress with the weight of the engine on it ? I don't want to over fill it .
Just like this...



You can't overfill it - if you try it will just run all over the ground.

You can either use dowels to provide the "holes" or you can use a 3/4" drill to drill it out later. (drill your pilot hole through the top and then expand using the 3/4" drill bit)
__________________
Current Stable
  • 380SL (diesel)
  • Corvette C5
  • Manx
  • Baja Bug
  • F350 Powerstroke
  • Auburn Boattail Speedster replica
Reply With Quote
  #13  
Old 11-19-2013, 04:56 PM
Registered User
 
Join Date: Nov 2013
Location: northern georgia
Posts: 16
The reason I ask about the mount compression is because the last ones i put on were popped up like a pyramid but as soon as I let the engine down on them they colapsed down to the k member . Is that normal ?
Reply With Quote
  #14  
Old 11-19-2013, 05:21 PM
mach4's Avatar
Registered User
 
Join Date: Jul 2011
Location: San Diego County, CA
Posts: 2,736
Quote:
Originally Posted by Trudge View Post
The reason I ask about the mount compression is because the last ones i put on were popped up like a pyramid but as soon as I let the engine down on them they colapsed down to the k member . Is that normal ?
Here you go - this is a 617 motor mount shown unloaded and loaded. This is very close to what you should expect, but be aware that the motor I have on the stand is the one out of the 380SL not the 617. The weight is a little less, around 50# or so, which means around 25# per side on each mount. I'm not sure you could measure the difference between the two engines at the mount.



And here's a fully collapsed mount.

Attached Thumbnails
engine mounts on a 300sd-mounts.jpg   engine mounts on a 300sd-mounts2.jpg  
__________________
Current Stable
  • 380SL (diesel)
  • Corvette C5
  • Manx
  • Baja Bug
  • F350 Powerstroke
  • Auburn Boattail Speedster replica

Last edited by mach4; 11-19-2013 at 07:01 PM. Reason: add image
Reply With Quote
  #15  
Old 11-19-2013, 08:21 PM
Registered User
 
Join Date: Nov 2013
Location: northern georgia
Posts: 16
awesome thx! yeah mine collapsed all the way down like that last pic as soon as all the weight was on them ....

Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 07:01 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page