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Old 07-05-2009, 08:41 AM   #1
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DIY front motor mount replacement w/pix

I just finished replacing my front motor/engine mount on my '02 2.7 using some of the other DIYs on the net. I thought I would add a few pictures and some impressions. I hope these pictures load properly since I'm not computer savvy. Also, I would certainly not rely upon this as a definitive DIY as I'm a liberal arts major and by no means a mechanic, so use it at your own risk!

-Jimmy

SIGNS OF A BAD MOUNT:

My symptoms were pretty classic for a failed front mount, i.e. bad vibration, particularly on decelleration, at around 3k rpm, clunking when shifting, and increased difficulty shifting into 1st, 2nd.

BEFORE YOU BEGIN:

In looking at the DIYs, I had problems conceptualizing how the mount sits in relation to the vehicle. I didnt' realize that you are actually dealing with 2 distinct pieces that you are trying to remove (that are nevertheless attached to each other via 2 bolts/nuts).

The 1st (most obvious) piece is the engine mount itself that contains the rubberized cushion piece that gets cracked, causing the vibration. The 2nd piece is the front yolk assembly that attaches to the engine mount via 2 (15mm) bolts/nuts and to the car's frame via 4 nuts/studs.

Here's a picture of the 1st piece, the shiny new engine mount attached to the front of the engine (you can see my finger pointing to it):

[IMG]engine mount.jpg [/IMG]

Here's a picture of the front yolk (2nd piece) that attaches to the car's frame via 4 studs/nuts:

[IMG] front yolk.jpg [/IMG]

SUPPORTING THE CAR/ENGINE - CLEARANCE ISSUES:

I placed the rear of the car on rhino ramps. In retrospect, I could have used more clearance, so I would definitely consider using jack stands next time around.

I then removed the rearmost plastic undertray (closest to the back of the car); I undid the front portion of the middle plastic tray since I saw no reason to remove the entire piece.

You next need to support the engine with either a floor jack or scissor jack. I used a scissor jack to have more room underneath to work. I place the scissor jack under a support piece (not sure what it's called) located in front of the oil pan.

[IMG]scissor jack new.jpg[/IMG]

ACCESSING THE VARIOUS BOLTS/NUTS:

I found it easier to access the two top bolts (particularly the one on the driver's side) that secure the engine mount to the front of the engine by removing the access panel behind the front seats. the passenger side top bolt can also be loosened from below, which I ended up doing by using a wratcheting wrench given the very limited clearance. Keep in mind, you are not removing these 2 top bolts, only loosening them. Here's a picture of the 2 top bolts:

[IMG] top bolts.jpg [/IMG]

Going underneath the car, I undid the pastic clamps that hold the coolant hoses to the front support yolk and slid the clamps off the yolk, while leaving them attached to the hoses; otherwise, you cannot push the hoses aside to remove the mount.

Making absolutely certain that the engine was properly supported by the scissor jack, I next removed the 4 (15mm) nuts/studs that secure the front support yolk to the frame. if the studs don't come out when you remove the nuts, you can use a 7mm socket to remove them.

Once these 4 nuts/bolt were removed, I lowered the engine gradually using the scissor jack. It is hard to say how far I lowered the engine (maybe 2 inches or so), but the point is to lower it enough to provide clearance to remove the lower 2 bolts (15mm) that secure the engine mount to the engine. Otherwise, these 2 very long bolts will not have enough room to be pulled out. After removing those 2 lower bolts, I was able to loosen the upper bolt on the passenger's side from underneath the car (once again, you don't remove this upper bolt, just loosen it). I tried loosening it from the top of the car through the access panel, but this was tough.

I then went from the top of the car (through the access panel behind seats) to loosen the top most bolt on the driver's side that holds the mount to the engine. You can do this from below, but I found going through the panel much easier and used a 15mm gearwrench ratcheting wrench to do it.

You are now ready to remove the engine mount and front yolk assembly, which is where clearance underneath the car is really helpful. I found the car too low on the rhino ramps to fit comfortably underneath to see what I was doing while trying to snake the mount mount assembly and front yolk out (and I'm a small guy). In any event, after pushing aside the coolant hoses, making sure not to put too much pressure on them, I was able to wiggle the mount/yolk assembly out from underneath the car. Again, this step takes patience since it's hard to see what you are doing since you don't have much room to work.

Once the assembly is removed, there are 2 bolts/2 nuts (15mm) that hold the engine mount to the front yolk assembly that need to be removed so that you can attach your new engine mount to the yolk. I got my engine mount from Sunset ($140 or $150, iirc). I installed the new mount to the yolk, torquing it 48 ft lbs.

The next step is to reinstall the entire assembly, which takes some patience and gentle moving/pushing aside of the coolant hoses to snake this cumbersome piece in. I read that some folks install the engine mount first and then install the front yolk assembly 2nd (i tried this initially, but gave up, installing the entire unit together).

The engine mount to the engine was torqued at 34 ft lbs, though I'm not sure how you would slip a torque wrench on those 2 upper bolts!

The yoke to the frame was torqued at 48 ft lbs. (this is where I raised the engine a couple of inches to get the yoke as close to the frame as possible to begin finger threading the 4 studs/bolts into the frame.

By the way, here's a picture of the old mount, you can see how cracked/shot it was:

[IMG]cracked mount.jpg [/IMG]



The results following swap:

Engine vibration gone, no more clunking.

Any questions, suggestions, or things you would do differently would be welcomed in this thread!

-jimmy

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Old 07-05-2009, 01:05 PM   #2
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Excellent write up, I just finished the same job, did you get the new mount with the triangular holes making it even a bit lighter? Anyway, The top bolt to the engine is the toughest as you have very little choice but to take small bites at it. I bled the clutch while I was down there and got four huge air bubbles out. With both repairs effected the difference is dramatic. The clutch engagement is very positive and the car accelerates smoother, it's almost as if you can feel the torque restored from the engine not rocking back and fourth with each shift...I know butt dyno nonsense but it feels 100% better, I think mine has been going since I picked the car up. It's incredibly gratifying to do, I love to work on the car, can you imagine how much the dealer is getting for that job? Many thanks to this forum which helps all of us be better mechanics.

Last edited by eightsandaces; 07-05-2009 at 01:08 PM.
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Old 07-06-2009, 07:26 AM   #3
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thanks.

The new mount does have the triangular openings (but the previous mount did as well and I think that change was made pre-02 models). However, I did get the updated version of the mount, which is the 987 part #. I believe this newer version is suppose to be more robust. interestingly, in looking at the old mount, I didn't see any tool marks on the bolts suggesting that this mount was original to the car ('02 base with 90k miles). So if it's the original, it lasted a lot longer than some other folks from what I've seen.
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Old 09-11-2010, 08:45 AM   #4
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In the middle of a motor mount swap and I thought I did my homework but...

Anyone know the correct torque specs for the motor mount nuts and bolts? I was going by Pedros DIY instructions which says everything is 34 ft-lbs but that seems a little light, especially for the connection between the yoke and the mount. Another post on this forum says 48 ft-lbs for this and the yoke to the frame with 34 ft-lbs for the mount to the engine. When I took things apart, it sure "felt" like things were tighter than 34 ft-lbs.

I don't want to over torque things but then again, I don't want pieces falling off later on. I guess for now, I'll do the two yoke bolts at 48 since you can't get at them once installed. The others I'll do 34 and tighten them up later if necessary.

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