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Old 11-02-2012, 07:04 PM
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Lightbulb I figured it out!

Son of a *****, I finally figured out what's wrong with my motor mounts and why I am getting so much vibration - the engine and assembly is forward enough, it's the angle that is the problem. The assembly sits on an angle with the trans dipping downward and the front of the engine tilted upward. With that being said the assembly is at a good setting when it comes to being forward or backward, but not when it comes to being up and down. Since the mounts are level (or close to I'd imagine) and the assembly is not, the top of the mounts look like the assembly needs to come forward and the bottom of them looks like it needs to go back, when in reality it is just sitting on too much of an angle. I've been fckng with this for weeks now and haven't been able to figure it out until today.

Alright, with that being said, what needs to be done to fix this issue? Do I need to space the trans mount upwards more? Anyone have a clue how much higher a regular brown dog mount sits compared to a OEM mount? Any help would be great, I just want to finish this project and finally enjoy driving my truck without it vibrating like crazy every time I am under 5mph.
Old 11-02-2012, 09:53 PM
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That's a busy paragraph friend. Maybe some pics or drawings would help solicit responses?
Old 11-02-2012, 09:58 PM
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Does it have a t-case drop? Maybe it's to much of a drop, that will affect the angle of the engine, seings how it is connected.
Old 11-02-2012, 11:09 PM
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When doing a TCase drop, always before restart insure your angle has not brought your fan into contact with radiator.
Old 11-02-2012, 11:17 PM
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Originally Posted by Vincenza V
That's a busy paragraph friend. Maybe some pics or drawings would help solicit responses?
I thought it was pretty clear

Originally Posted by TheDale
Does it have a t-case drop? Maybe it's to much of a drop, that will affect the angle of the engine, seings how it is connected.
Originally Posted by peep
When doing a TCase drop, always before restart insure your angle has not brought your fan into contact with radiator.
No transfer case drop on it, SYE instead.
Old 11-02-2012, 11:22 PM
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Hmm, then maybe check the trans/t-case crossmember mount, maybe it broke or is bad and letting the trans hang down low.
Old 11-02-2012, 11:31 PM
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Right now I am thinking that I just need to make my own trans mount adapter about a 1/2" to and 1" taller to make it fit correctly. I contacted Rubicon Express about it since it is a full 5.5 LA kit and should have the right sized trans adapter. The trans mount is new, but can it be the wrong one? It looks identical to others I see.

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It's definitely too low, you can see by the stress on it.
Old 11-03-2012, 10:16 AM
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Originally Posted by CrawlinPepper
Son of a *****, I finally figured out what's wrong with my motor mounts and why I am getting so much vibration - the engine and assembly is forward enough, it's the angle that is the problem. The assembly sits on an angle with the trans dipping downward and the front of the engine tilted upward. With that being said the assembly is at a good setting when it comes to being forward or backward, but not when it comes to being up and down. Since the mounts are level (or close to I'd imagine) and the assembly is not, the top of the mounts look like the assembly needs to come forward and the bottom of them looks like it needs to go back, when in reality it is just sitting on too much of an angle. I've been fckng with this for weeks now and haven't been able to figure it out until today.

Alright, with that being said, what needs to be done to fix this issue? Do I need to space the trans mount upwards more? Anyone have a clue how much higher a regular brown dog mount sits compared to a OEM mount? Any help would be great, I just want to finish this project and finally enjoy driving my truck without it vibrating like crazy every time I am under 5mph.
A Brown Dog Mount is exactly the same height as a new OEM mount.
Old 11-03-2012, 10:22 AM
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Originally Posted by CrawlinPepper
Son of a *****, I finally figured out what's wrong with my motor mounts and why I am getting so much vibration - the engine and assembly is forward enough, it's the angle that is the problem. The assembly sits on an angle with the trans dipping downward and the front of the engine tilted upward. With that being said the assembly is at a good setting when it comes to being forward or backward, but not when it comes to being up and down. Since the mounts are level (or close to I'd imagine) and the assembly is not, the top of the mounts look like the assembly needs to come forward and the bottom of them looks like it needs to go back, when in reality it is just sitting on too much of an angle. I've been fckng with this for weeks now and haven't been able to figure it out until today.

Alright, with that being said, what needs to be done to fix this issue? Do I need to space the trans mount upwards more? Anyone have a clue how much higher a regular brown dog mount sits compared to a OEM mount? Any help would be great, I just want to finish this project and finally enjoy driving my truck without it vibrating like crazy every time I am under 5mph.
just throwing this out there... the engine and the transmission should be the same angle. if there is a difference... i would look at the bellhousing.
Old 11-03-2012, 10:42 AM
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How much of an angle? The engine and tranny are actually supposed to be pointed slightly upwards.
Old 11-03-2012, 11:03 AM
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The engine and trans look like they are at the same angle, if there was a bell housing issue I think it would've caused crazy vibration. They are both at an angle upwards, it just seems like the trans mount needs to go up 3/4"-1".
Old 11-03-2012, 11:13 AM
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This makes no sense.

Transmission and engine are bolted together nice and snug?

Motor mounts are good?

Trans mount is good?

No xfer case drop?


I'm sorry, but try driving without your rear drive shaft.
Old 11-03-2012, 12:10 PM
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Assembly is bolted together nicely.

Motor mounts are brand new Superflex rubber mounts from Brown Dog.

Trans mount is brand new from Autozone.

No transfer case drop.

The only thing I can think of is that Rubicon Express might have put a lower sitting crossmember on their 5.5" lift to help match up with a t-case drop. Just a thought, haven't been able to get a hold of them since it is the weekend.
Old 11-03-2012, 12:16 PM
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Dude just wheel the damn thing and maybe it will just settle. I am here for you Ghost
Old 11-03-2012, 12:18 PM
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Here are two pictures of the passenger side mount.

This one you can see the space up top but no space on bottom.
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You can see how the motor mout is flat on top but the bracket is slightly slanted down towards the rear causing the bracket to sit slanted on the mount. Also note that the rubber on the right is smashed between the bracket and the mount.
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