Bad Motor Mount

[Izzmo]

I just got a rebuilt tranny about a year ago now and it's always done this (even on my old tranny). Here's the situation (what it does):

Get in turn lane to get on highway
On the on ramp, get up to about 60-70 (on a 70mph speed limit)
When the tranny wants to engage OD, it will really hit it hard and sometimes even hit so hard it will unlock it and try again.

This is really bad when the engine is cold/just got to operating temp. After driving for a while it still does it, but not so bad to where it will disengage after hitting it so hard, but there is always a thump.

So.. could this be a bad motor mount?

If I were to look at the mounts, how would I know if it was bad?

 

[SHOZ123]

Open hood and brake torque the engine. You will see a lot of movement if the mount is bad.

 

[Izzmo]

Ideally, is there supposed to be no movement of the engine?

 

[welcome2daSHO]

my front motor mount comes loose sometimes and when its in drive it makes a clunking noise when i hit the gas. no there isn't supposed to be any movement of the engine.

One way to check is open the hood, put the parking brake on and put it in drive, tap the gas pedal slightly and you'll see the whole engine move like six inches upwards, that way you know its the front motor mount.

 

[three50one]

Six inches is a lot of distance.

There will be some movement as with all engines, unless you're using solid mounts. Take a video if you can if you aren't sure if it's too much movement.

 

[welcome2daSHO]

yea, it'll move at least six inches if your front motor mount isn't attached or broken.

 

[Izzmo]

I found this video hilarious... bad motor mounts. I don't think mine are this bad.

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[venom]

I found this video hilarious... bad motor mounts. I don't think mine are this bad.

The factory mounts allow quite a bit of movement. I'd say 2" rearward is totally plausible. There is no reason why you can't set the parking brake real good, put it in drive and gently open the throttle while underhood - obviously keep your feet away from the tires or their potential path.

 

[Izzmo]

So, I think my front mount is bad, possibly my rear, not sure on that though.

How hard is it to change out motors mounts at all 3 positions? (Which one is hardest too?)

 

[three50one]

The rear is hardest. Have to drop the subframe a bit, but you can get it. It only took me 2 hours to do all three in the driveway, but I was distracted. Have to jack the motor up so make sure you have a decent 2x4 or your preferred size for your oil pan. My front was ripped where it bolted. I suspect your front to be similar.

 

[Izzmo]

But overall, if you have dropped the subframe before.. they should all be pretty straight forward?

 

[venom]

But overall, if you have dropped the subframe before.. they should all be pretty straight forward?

I did both front and rear in the parking lot at the indy convention in an hour or so. Jackstands under the car, floor jack with a block of wood across the oil pan to elevate the engine (after removing the nuts that hold the mounts down to the SubFrame) a bit and you can unbolt the mounts from the brackets that hold them to the motor without major event. Note that the rear only goes in one way.

If you buy new ones Urethane filling them is what I would do if a little added NVH doesn't bother you. I searched briefly but didn't find where I posted the procedure for urethane filling here anywhere. I think Dan did a write-up on TCCA but the forum over there seems to be down presently.

 

[Izzmo]

Okay, here is a video.

Just today it started squealing/rubbing. So.. let me know what you think:

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[venom]

Okay, here is a video.

Just today it started squealing/rubbing. So.. let me know what you think:

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I can't figure out the sound... But that is what I would expect for normal movement of a car in park with acceptable factory mounts if you are rolling it back and forth fairly hard while in park.

 

[Izzmo]

I am going to post another video tomorrow with the car in drive and pressing on the gas thing while holding the brake down.

As for the sound, I couldn't figure out where it was coming from either. It was coming in the direction of either the mounts, but more in the middle of the tranny mount and the rear.

 

[Izzmo]

Motor mount video

Here is a video of the drive-and-brake thing.

In drive is the first part of the video, then reverse when he said, "Alright" somewhere in the middle.

It looks like the reverse moves more than the forward gear.

Let me know!

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[venom]

Looks normal

The video you just posted looks normal for stock motor mounts.

 

[Izzmo]

Well that's good and bad news I guess...

 

[LJRuddy]

Nick, I can go take a quick video of my 96 for comparison... My mounts are in good shape. :wave:

 

[Izzmo]

That would be awesome Liberty, thanks man.