ENG: Ballistic Rubber Torque Mount Insert

[Fleetw00d]

I've seen the threads on using urethane to fill an existing torn mount; I tried a couple using Flex Seal liquid rubber (may not have cleaned them well enough, it didn't seem to stick well) because I already had it around. I have a large block of ballistic rubber I used to make body mounts for my 99 E350 van, so I thought I'd try to make a solid insert for my torque mount.

Tools Needed:
2.5 inch hole saw
68 mm hole saw (64.7 mm inside diameter)
1 inch drill bit or spade bit
Sharp blade of some kind (I used a sharpened putty knife)
Hammer

Remove the front torque mount from the car; this is covered in other threads in the DIY section.

Use the 2.5 inch hole saw to cut the remaining rubber from the large end of the torque mount. If it is not already torn completely away, cut the center metal bushing out of the rubber first. Use the sharp blade to cut the rubber off the center metal bushing.

20200404_094117_resized by Paul Kemme, on Flickr

I had smaller block of rubber already cut from the larger block. I cut the end of this piece to the thickness of the mount.

20200414_200308_resized by Paul Kemme, on Flickr

Use the 68 mm hole saw to cut a round piece from the rubber. I was only able to get about halfway through the block using a drill, even with lubricant applied to the saw. I then had to manually turn the saw to keep it from heating up. I need to figure out a better way to do this.

20200414_204809_resized by Paul Kemme, on Flickr

I used a grinding wheel to trim some flash and chamfer the outside edges some.

20200414_205525_resized by Paul Kemme, on Flickr

Using a little soapy water, I was able to press the rubber into the mount about half way; I then used a hammer to persuade it the rest of the way in. I didn't use any adhesive for this trial, but I suspect the interference fit will keep it in place.

20200414_210042_resized by Paul Kemme, on Flickr

Use the 1 inch spade bit to bore a hole through the rubber. Somehow, the 1 inch bit didn't bore a 1 inch hole, but I was able to manually start the center bushing (about 1.07 inches diameter) into the rubber, then a hammer (supporting from the opposite side) to drive it the rest of the way through. I didn't intend for this to be quite this offset; I'll see if it is a problem when I try to install it.

20200414_212750_resized by Paul Kemme, on Flickr

I could probably get several dozen bushings out of the block I have if any one is interested. I have several bad mounts that I may go ahead and repair.

April 17, 2020: Installed it last night, the offset actually just about centered it in the slot in the bracket on the engine. This was after I installed the Innovative rear mount.

[toycar]

Nice work

I have done this on several builds. I prefer to punch the center hole and insert the center bushing while the rubber was on the bench. Before drilling the center hole I ran a 1/4” bolt through the center hole created from the hole saw guide and using washers and nuts tightened the rubber insert in place, then tightened the bolt shaft in the chuck of a drill. Using the drill to rotate the bushing and my bench sander I was able to clean up the edges of the insert very nicely.

Nice write up though

[Fleetw00d]

Thanks, I didn't think about spinning it to clean up the faces and corners to make them more uniform.

If I had a lathe, maybe drilling a center hole and turning the OD would be easier than trying to use the hole saw to cut it out of the block.

What kind of rubber block did you start with?

The rear mount I took off was in bad shape. It doesn't use a round insert; if I can figure out an easier way to cut the rubber to a specific shape, I could probably make an insert for this one as well - another DIY.

[toycar]

Thanks, I didn't think about spinning it to clean up the faces and corners to make them more uniform.

If I had a lathe, maybe drilling a center hole and turning the OD would be easier than trying to use the hole saw to cut it out of the block.

What kind of rubber block did you start with?

The rear mount I took off was in bad shape. It doesn't use a round insert; if I can figure out an easier way to cut the rubber to a specific shape, I could probably make an insert for this one as well - another DIY.

I have used several rubber mallets. Not sure on the grade of rubber. They were shy of 3” diameter to begin with. Held up well

[Rilas]

Prothane makes a rear mount insert Paul. Just and FYI, like $15.

[Fleetw00d]

Prothane makes a rear mount insert Paul. Just and FYI, like $15.

That insert assumes the one in the vehicle is in good condition, mine was trashed; the metal cylinder through the center was completely torn out of the rubber.

20200418_182201_resized by Paul Kemme, on Flickr

When I say "insert" I'm talking about cutting a single piece of rubber to fit in the OEM metal mount similar to what I did with the front torque mount - I cut out all the old rubber. It would be more like the Innovative mount I installed in the rear.

[sonikaccord]

That is really creative! How would you compare the stiffness of the rubber to stock?

[Fleetw00d]

That is really creative! How would you compare the stiffness of the rubber to stock?

Well, since the rear has been bad for probably a while, and the FlexSeal filler I had in the front mount was starting to come out, installing the Innovative rear mount and the ballistic rubber front mount made it very stiff. Before, the engine probably rocked an inch up/down at front and rear when engaging the clutch (I could rock it quite a bit just by hand). Now, when engaging the clutch (first gear or reverse) the engine doesn't move. Down side is more vibration at idle with the clutch disengaged. When engaged and driving, some "buzzing" felt through the steering wheel and the rest of the car. This may be accentuated by the exhaust leak in the flex pipe.

After some more driving, the buzzing is primarily during deceleration with the clutch engaged; not much when accelerating/maintaining speed.

April 25, 2020: I've got another one ready if someone wants to try one.