Bad motor mount issue on driver side

[Xposure]

Well my exhaust started rattling on something so I climbed under to see what was going on. My driver side motor mount is bolted to a bracket that's attached to the block. That bracket is twisted and broken. Any thoughts on what caused this? Top side everything looks good.

Thoughts??

 

[Xposure]

That top back bolt looks like it goes through the mount, the bracket, and into the block? And it appears to be pulled back....if it goes into the block I hope it hasnt stripped it or cracked it. Can anyone confirm it that one I'm refering to goes through into the block?

 

[Weld_daddy]

I’ve got a 2000 with the 4.0. Mine looks quite different. Hope this helps

 

[pagrey]

Mounts break off the block, the bolts just break or some get loose causing others to snap. Brown dog makes a super bracket that uses some other bolts depending on what you have left that might help out if you can't repair what you have. I'd support the engine and pull it all apart to see what you have left before anything else breaks. Somebody might have already welded something custom to fix yours.

 

[CharlesHS]

Here are a couple pictures from my '01.
I believe the previous owner left the damaged motor mount in too long and mangled the attachment point

I believe that Brown Dog Offroad has mounts that will fix your problem .

 

[Xposure]

I’ve got a 2000 with the 4.0. Mine looks quite different. Hope this helps

View attachment 184304

View attachment 184305

View attachment 184306

Your right, it looks like someone has added that lower brace that's all messed up. I bet when I get it off I'm going to find out that the factory block bolt holes were ruined and someone added that bracket to use the outer bolt holes.

Thanks for the pics, they help a lot, I wasnt sure if that bracket was OEM or added.

 

[Xposure]

Does that Brown Dog mount really address the root issue? Is the issue that the stock design is just weak and breaks.....or is there a underlying issue that causes excessive movement? All my motor (and trans) mounts look to be okay but somehow the engine must have been moving a ton or at least putting a ton of strain on that one mount.

That's what I'm trying to understand.....just want to make sure that a upgraded mount is really solving the problem vs masking a underlying problem. I dont even drive it hard at all, rarely even give it more than 1/4 throttle and 99% street driven.

@Jerry Bransford you've been working TJ's hard forever, have yours done this?

 

[Xposure]

Should the rubber motor mounts be the same height on both sides? It looks like my passenger side is approx 2" tall and the drivers side approx 3" tall. Does that sound right?

 

[pagrey]

The motor mounts are the same, there is no left and right.

 

[MountaineerTom]

It’s hard for me to tell in the picture, but inside the circle looks like what’s left of a snapped off bolt. Where the arrow is pointing, looks like a broken weld or ripped metal.

Maybe there were bolts snapped off in the block and someone made that strip of metal into some kind of homemade adapter and bolted the motor mount to it, maybe?

 

[Xposure]

Can anyone confirm how tall the stock motor mounts are? It appears that mine are approx 2" on passenger side and 2.5" to 3" on drivers side. It's hard to see exactly because I'm looking at the tape from a low angle looking upward at it. But the drivers side certainly looks at least .5" taller.

Maybe the drivers side homemade bracket sits lower on the engine than stock so they had a taller mount to compensate?

 

[CharlesHS]

The Brown Dog mounts use more of the threaded bolt hole bosses that are available in the block to make a stronger mount.
The original BD stronger mounts were designed approximately 13 years ago for the XJ and ZJ when a strengthened mount was needed or where the original two engine mount bolt holes were damaged beyond repair.

 

[Xposure]

So is this real common on TJ's? I dont hear it talked about much or no one suggesting to install a beefy mount before it gets ripped out of the block.

This leads me to think there may be another issue. Do you think at some point someone just tried replacing the mounts, snapped the bolts...so made this bracket to reach different holes instead of just extracting the snapped bolts?

Should I get a upgraded mount for both sides? My passenger side appears to look okay....but if this is a common issue maybe I should do both sides so theres not a issue later.

 

[CharlesHS]

This leads me to think there may be another issue. Do you think at some point someone just tried replacing the mounts, snapped the bolts...so made this bracket to reach different holes instead of just extracting the snapped bolts?

Should I get a upgraded mount for both sides? My passenger side appears to look okay....but if this is a common issue maybe I should do both sides so theres not a issue later.

I believe your suspicion about the previous owner not wanting to extract the broken bolts and fabricating these mounts to replace the stock mounts. You should see if you can extract those broken bolts; that way you can use the stock mounts instead of spending the money to install the BD mounts.

 

[Xposure]

I believe your suspicion about the previous owner not wanting to extract the broken bolts and fabricating these mounts to replace the stock mounts. You should see if you can extract those broken bolts; that way you can use the stock mounts instead of spending the money to install the BD mounts.

Yeah, I think I'm going to get the Jeep up to my brothers shop tomorrow and pull it all off and see what's going on.

 

[Xposure]

Here are some better pics of what I have.

 

[CharlesHS]

Those pictures confirm there are problems with the bolts and holes. It will be interesting to see what the bosses look like on that top left bolt.

 

[Xposure]

So I'm looking and comparing my face on picture with the one Weld_daddy posted. On his, it appears the bottom edge of the mount is RIGHT AT the oil pan lip but mine is a 1" or so above that. So the mount has been moved higher up. In this image, it appears the red circled hole is the original bottom bolt location and that its snapped off.

What is the hole that the blue circled bolt is going into? Is it a factory hole or something a prev owner created?

This confirms what I noticed earlier about the rubber motor mount on drivers side being taller. In effort to raise it higher on the engine without this side sagging lower, they used a taller mount on this side.

Can anyone confirm how tall a stock motor mount is? I need to measure this one and see if I need to replace it....if I lower the mount to the factory location I may need a shorter motor mount....just need to verify.

 

[CharlesHS]

The red circle does indicate a broken bolt inside the boss and the blue bolt I believe may be a stud that is welded to the fabricated mount. The stud to the upper right of the blue bolt is a bolt pushed thru from the back of the new mount. You will need to remove what is presently installed to verify what the PO has done....
Depending upon your success with removing the broken bolt(s) will determine if you will need to purchase a Brown Dog mount.

 

[Xposure]

The red circle does indicate a broken bolt inside the boss and the blue bolt I believe may be a stud that is welded to the fabricated mount. You will need to remove what is presently installed to verify what the PO has done....
Depending upon your success with removing the broken bolt(s) will determine if you will need to purchase a Brown Dog mount.

Yeah, my brother has a shop a few miles away, I'm going to limp it up there in the morning and tear it apart.

What worries me about extracting bolts is I've always heard it's easy for cast to crack and/or break off in chunks. Has me wondering if I want to try to extract them or just install the BD mount and use all the free holes I can with it. (It says it has 8 bolt locations)