Jump to content

should I change these engine mounts?


Tom Boehm

Recommended Posts

These are the original engine mounts from my 1973 Dodge Dart 318 V8. They are out of the car because I am doing other repairs. I want to reuse these because I like to use as many original parts as possible. However, I don't want to put these back if they are bad. Can you tell by looking at them if they are bad? I am considering NOS Mopar replacements. I also considered filling the air voids with silicone if they are bad. I heard that might increase the stiffness and the vibration. I considered polyurethane inserts but I also heard those would increase the vibration. I have heard that the new aftermarket  replacements with rubber are not durable and not stiff enough. I don't want to have to take these out in the future so I want to get this right.  Thoughts....

DSCN6556.JPG

DSCN6557.JPG

Link to comment
Share on other sites

The voids are there to tailor the NVH (noise, vibration, and harshness) characteristics of the car. Filling them will certainly increase the amount of engine vibration transmitted back into the structure of the car. These are normal wear items. Replace them.

Link to comment
Share on other sites

OK the consensus is to replace. What do you all think about NOS? They are available on eBay and other sources. Would that work or is that just substituting one piece of 50 year old rubber for another? Is unused NOS rubber still useable or pliable?

Link to comment
Share on other sites

25 minutes ago, Tom Boehm said:

OK the consensus is to replace. What do you all think about NOS? They are available on eBay and other sources. Would that work or is that just substituting one piece of 50 year old rubber for another? Is unused NOS rubber still useable or pliable?

NOS rubber products in my experience do not last. Look to install new. Drive happy.

  • Like 1
Link to comment
Share on other sites

How are the cylinders containing the rubber replaced? Is a shop press required? There are two versions of new sold. One is the entire mount with the bracket. That is ready to install. The other is just the steel cylinder with the rubber inside. The old steel cylinder must be removed from the bracket in order to install the new ones. How do the old ones come out? Do they just slip out if the two factory crimps are hammered/ground off? Is it necessary to use a shop press to remove and install? How is the factory crimp "re-created" when the new part is installed? 

If this is a lot of trouble I will just buy the entire bracket new. 

Link to comment
Share on other sites

Replacing those bushings is no different that changing suspension bushings. In this particular case, those bushings are staked, as you can see on the backside. Those areas need to be ground away or otherwise straightened before attempting to remove them. The other problem is that those bushings are oval, which requires oval tools to press them out. I'm sure the factory had such tools, but you'd need to find them. I've had success with flattening the sheet metal sleeve from the side, which loosens it in the bracket to simplify removal. Reinstallation can be done with a hammer, block of wood, and a bench vice. Note that you need to cut a length of angle iron to fit inside the bracket to avoid crushing it when you reassemble. Yes, you'll need to repaint. Or, buy the new ones already assembled. Your call.

Link to comment
Share on other sites

On 4/15/2022 at 4:10 PM, Tom Boehm said:

These are the original engine mounts from my 1973 Dodge Dart 318 V8. They are out of the car because I am doing other repairs. I want to reuse these because I like to use as many original parts as possible. However, I don't want to put these back if they are bad. Can you tell by looking at them if they are bad? I am considering NOS Mopar replacements. I also considered filling the air voids with silicone if they are bad. I heard that might increase the stiffness and the vibration. I considered polyurethane inserts but I also heard those would increase the vibration. I have heard that the new aftermarket  replacements with rubber are not durable and not stiff enough. I don't want to have to take these out in the future so I want to get this right.  Thoughts....

DSCN6556.JPG

DSCN6557.JPG

 

Buy new. Here on Rock Auto for $6.00-$13.00.

 

https://www.rockauto.com/en/catalog/dodge,1973,dart,5.2l+318cid+v8,1088603,engine,motor+mount,5552

Link to comment
Share on other sites

  • 4 months later...

In the end I bought the entire engine mount replacement that includes the bracket and new rubber. Even thought they were made in USA the steel on the new brackets was much thinner than the originals. I decided to reuse the factory original brackets. I unbent the factory crimp on the old and new. The steel oval cylinder with the rubber just slides out then. I put the new inserts in the old brackets. I could not reproduce the factory crimp very well so I put a dot or two of weld between the insert and the bracket to ensure it does not move. I did that several months ago and it seems fine. Thanks for your responses!

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...