So I was taking out my tranny to put in my Clutch and I noticed something about the factory torque dampers (the front and rear motor mounts). I'm not going to try to describe it, I took pics.

The bolt that uses on the front and rear mounts is smaller in diameter than the inside of the sleeve in the mount on the crossmember. See pic:



Yet the bolt fits the hole in the bracket that attaches to the tranny perfect:



If you look inside the braket, you can see where the mount sleeve has made a mark larger in diameter than the hole that the bolt goes through:


BTW: It is like this on the front and rear mounts, the same thing except the rear bracket is aluminum.

So here's my question... why would do this?

I am considering enlarging the holes on the brakets and using bolts that actually fit the diameter of the mounts. This would eliminate the potential for the mount to slip and have slop. This potential slop is a place that could cause wheel hop real easily IMO. Give me some feedback here guys, what do you think? What should I know before I go at my brackets with a drill?

- Steve

 

Good find! That just looks really stupid of them to do. That's a HUGE difference and I'm supprised people haven't snapped those bolts yet. Please do a complete write up on this with pictures from start to finish. Diameters of holes drilled and stuff like that would be much appreciated as well.

 

yeah, not sure if I'm gunna drill it out yet, but I'm pretty sure I will. I've got time to think about it, I gotta wait a couple weeks while I have my tranny and t-case built by TRE.

 

...or you can find/machine a spacer sleeve. However, from the looks of your pictures, there has not been any movement there.

 

The spacer is a good idea, then I wouldn't be irreparably changing any of the factory parts.

Yes, I agree there has been no movement, but that doesn't meant it won't move in the future.

 

True enough...

 

I agree that the picture seems to indicate that the sleeve has not moved, but due to the reduced diameter of the bolt, won't the engine still move more than it would if the bolt were the same diameter as the sleeve? If so, the dampning properties of the bushing are diminished because the motor can "rock" within the free space betwen the bolt and the sleeve before the bushing is ever loaded.

 

I am guessing here but it looks like the mount and bolt are not quite lined up. So this is either an assembly aid or a complex engineering feature. so you will either make no difference or screw some up.

ha ha big help huh.

 

Perhaps something incorporated for impact in a crash. The space may allow some movement to help absorb some of the impact....

 

If the bolt were loose enough for it to move, then yes it would "rock" causing excessive engine movement. It's hard to see in the pic but mine has moved a small amount. I wonder if other people's cars have the bolts loose enough that the mount "rocks" though.

I would believe it to be an assembly aid before I ever believed it to be a complex engineering feature.

I think the choices should be: Make a small difference, no difference, or screw something up.

I'd also have to say that since the contact ring is rusty and there's a second ring (it's hard to see in the pic) that is more faint that the mount has moved some over time.

I don't really see how I could screw something up, but I guess we'll find out.

That's a good theory, but that small amount of space will have very negligable (if any) impact on the cars behavior in a crash.


I'm just going to fabricate some spacers to take care of the slop. If I notice a difference, great, if not, I don't think I'll be hurting anything.

- Steve

 

I got the smae thing! How retarded is this design

 

It's there to allow easier installation, that's it. Once torqued down the sides of the brackets on the tranny will clamp onto the metal sleeve and lock the assembly in place, you do not need a spacer.

 

Yea I just reinstalled today, it's so tight the bolt barely fits, thus pushes on the front side wall. Lame design, but i suppose it works.

 

The bolt does not move if it is tightened to spec. It is built that way on purpose. the main motor mounts settle. The hole needs to be larger to compensate for settling.

Mitsubishi is not stupid. This thread is.

 

That's like saying we've created a new hood with 1" panel gaps to allow for the the body to flex