This is kind of a long-shot question I know, but I'm in the process of putting a 5.2 in my '89 4WD Dak and I've found that the motor mounts on 4WD Daks changed once Dodge started putting V8's in them (around '92 I think). The rigid parts of the mount are the same, and the geometry is the same, but where it attaches to the chassis the round sleeve w/the rubber inside is about 2" wider and has a slightly smaller diameter. Likewise, the mounting bracket on the chassis is about 2" wider. I'm sure it was meant to better accommodate the Magnum V8's weight and torque.

I could use the V6 mounts but it doesn't look like they'd last too long, so I'd like to beef them up a bit. I don't want to cut and weld the brackets. What I have in mind is to stiffen the mount by adding a pour-in urethane to the hollow areas around the rubber. I know the Neon SRT/Honda guys use this trick to stiffen their mounts all the time, and it seems like it might work to give my mounts more resistance, and help the rubber portion hang in there longer.

Does anyone here have any experience with this, or have any alternative ideas? Here's a link describing the pour-in urethane process for motor mounts if you're interested:

http://www.superhonda.com/forum/f94/...mounts-204274/

 

idk about the urethane, but I,ve ripped atleast 4 motor mounts in half. getting sick of it. as much as I hate to do it, im thinking the only good option is solid mounts.

 

Are you having trouble with Dakota mounts, and are these encapsulated style mounts w/the rubber surrounded by metal (4WD type), or flat, pad-type mounts (2WD)?

Also, which kind/brand of urethane have you tried? (edit - Never mind, I just realized you said "idk" about urethane...)

 

Take a look at attention mounts of a 1991 v8 Dakota they will probably look more familiar to you. The mounts changed in 92. If I remember I'll try and snap a pic of mine.

 

Some pics of your mounts would be nice. I use "3M Windshield Weld" to fill the mounts on my turbo-van and other vehicles.

 

I just checked the images on the RockAuto site. I like their site because they show the actual mount for the year in question. Looking at the '91 4WD V8 mount the rubber sleeve insert is wide, just like the '92. The '91 4WD V6 mount is wide also, but the extra width comes from the center tube which extends out beyond the rubber, so its the same width as the V8 mount , but has less rubber material.

The '89 and '90 4WD's are V6 only, and when you look at those mounts they look just like the 4WD '91/'92 V6, except without the extra center tube width sticking out (so they're narrower). Here's a comparison of my '89 mount and a '92 V8 mount, and also the '91 V6 & V8 mounts:

http://i792.photobucket.com/albums/y...psbe92eca5.jpg

http://i792.photobucket.com/albums/y...ps8a2707fd.jpg

http://i792.photobucket.com/albums/y...psc35a897e.jpg

 

AZ, the first picture link in post #6 has my mount on the left, and a '92 V8 mount on the right. The next two pics from RockAuto show the rubber parts better.

How has the 3M Windshield Weld worked for you?

 

God Photobucket sucks ***** now since they changed their format. Here is the front mount for my SRT-4 Caravan before:

And after filled with 3M windshield weld:

I like the 3M windshield weld because it's quick (to fill the mount, it's in a tube you use in a caulking gun and you don't have to tape off the mount) and not so messy. The only problem is it's not as stiff as other poly fills and it takes a week for it to dry, depending on how deep the mount is. It really helps to prolong the life of mounts when they are the major support for the engine. It keeps them from sagging and prematurely wearing out the mount.

 

Good info, thanks AZ. I'm not looking for stiffer mounts in this case, though that may be the end result since it looks like the only way to beef-up the mounts other than fabbing up something. It looks like you cleaned up the rubber real good (or maybe used new mounts) before putting the urethane in. I'd imagine that helps w/the bond, something I think some people neglect, then they complain that the urethane failed.

Stock motor mounts have a durometer of about 40-50 (Shore A) from the research I've done. I'm considering adding either a 40 or 60A material. The factory voids in the mounts probably help soften the vibrations quite a bit, so no matter what I add I think its going to stiffen them. That has me leaning to the 40A urethane.

 

Looking at my motor mounts again, the void space is not that much. Anything I add in the way of urethane is probably going to take up no more than about a third of the total area. That being the case, I'm going to go w/shore 60A hardness, which is slightly firmer than stock motor mount rubber.

My WAG gauge tells me that should be about right for the additional weight/torque of the 5.2.