Frustrated and exhausted - changing the GXP motor mount

[skregal]

This has been the longest and hardest day of wrenching on one of my cars that I have ever experienced.
I started at about 11:00am and worked until dark - about 8:30pm. My hands
and arms hurt, they're busted and bleeding and I'm covered head to toe in grease and dirt.
AND THE JOB STILL ISN'T FINISHED.

I actually have the new mount installed - mostly. I am still putting things back together,
but I'm having big issues that started with something I read from a write-up on this forum.
Don't get me wrong, I am grateful for the write-up and would never of tried doing the front motor
mount myself without the help of the guys in this club. I believe several have changed
their mounts using this method, so it must work for them.
The procedure for changing the mount is the one that raises the engine and drops the sub-frame
to get enough clearance to remove the mount and bracket.
http://www.pontiacbonnevilleclub.com/fo ... 33837.html

Here is the problem.
The write-up done by a member, and then updated by another, states that in order to raise the
engine you remove the bad front mount and then unbolt the two side mounts while jacking up the
engine. Well the passenger side motor mount cannot be removed, at all. At least not on
my car. Two of the four bolts don't have the clearance from the transmission or the frame
to be unscrewed enough to let loose of the engine. They can only be removed with the engine completely out of the car.

Look at this picture:
This bolt collides with the transmission housing near the drive shaft output. There is no
way to remove this bolt to allow the mount to be free.


The bolt head is now scarring the transmission and if I keep messing with it,
it may rub a hole in the housing. There is a second bolt on this mount that
is even tighter and hits the frame near the engine pulleys. Needless to say I
was never able to raise the engine enough to get the space needed to remove
the bad front mount and bracket. This bolt is sideways because of the raising and lowering
of the engine while trying to remove the stupid front mount. It was just loose,
now it's jacked.

I came up with other solutions for removing the bad front mount, but I still have this
issue with this lodged bolt wedged between the transmission and the passenger
mount bracket. I think I will have to cut the head off the bolt and only have
three bolts holding this mount instead of four.

[repinS]

The two side mounts should not have to be removed, only unbolted to let the engine tilt and rock upwards. #20 and 31 in the diagram. I am guessing you have issues with #19?

I did remove the passenger side mount at one point to check it. nut and bolt 34/37 were a royal pain in the ass, had to do it blind. The belt drive assembly kills any sort of clearance to work with.

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[skregal]

Actually it is the passenger side mount that caused all the problems.
The diagram doesn't show all the four bolts that hold it to the block.
There are two facing the wheel and two facing the rear of the car.
#32 is the two easy ones, they don't show the problem ones.

But unless you remove these bolts the engine will not have very much movement
at all with them only loose. On the drivers side mount I had the mount
holes about one inch out of alignment when I had the engine jacked
to it's highest point. That can't happen on the passenger side unless
the bolts are removed.
Loosening the larger bolts that hold those side mounts to the frame (34, 35) won't
do anything because the side mounts are under the frame and will still prevent the
engine from moving upward if they are still attached to the engine.
Maybe I am still misunderstanding something.

Anyway. Lacking the clearance to remove the infamous mount and bracket I had
to improvise. This is what I did if anyone has the same issues.

First I hack sawed the long bolt on the old mount to free it from the car frame.
Next I clamped the bracket upside-down to the frame exposing
the 30mm top nut holding the mount to it's bracket. I had my son hold a pry
bar in the bracket providing opposite pressure as I loosened that nut.

It is easy to get the bracket and mount out once they are separated.

I noticed that the old mount had about 3/8 inch of long bottom bolt that
passed through the nut under the frame and stuck out the bottom when
it was fastened. I figure that 3/8 inch is not providing any holding power,
so I sawed that much off the new mount bolt, which gave it enough
clearance to get back in place.

That long mount bolt barely peeps out the underside of the
nut now that it's installed.
I know GM probably engineered the bolt to be longer so that if the nut
shook loose it would travel a longer way before it finally spun completely
off the bolt. I put thread locker on it, and since I change my own
oil, I will look at it every time I'm under the car. I really can't imagine
it coming loose, I cranked it darn tight.

The whole process took me.....TA DA!!!!.... 13 hours.
I am not happy about that, and I am really sore all over my body
especially my arms and hands.
Maybe paying the dealer $800 would have been worth it.

[CMNTMXR57]

Sorry to hear the frustration. Some things you'd think would be pretty straight forward, sometimes become royal PITA's.

[repinS]

It's been a little while since I've done this, so I'm trying to wrap my mind around it again.

If memory serves correct, the idea is that you unbolt #24, #31 and #20 in conjunction with unbolting the front bolts on the subframe. This allows the entire powertrain to drop down. Using your jack, you raise the powertrain again as high as it can go. While it doesn't give you much extra clearance, if any at all, it does let you wiggle around your powertrain that little bit extra in order to get the front mount and bracket in and out.

[CMNTMXR57]

Same here.

But in all fairness, I did them on lifts, in a shop with the proper lift/support equipment, so that can skew experiences a little.

[1tinindian]

Same here.

But in all fairness, I did them on lifts, in a shop with the proper lift/support equipment, so that can skew experiences a little.

Having a lift to work off of makes all the difference.
It only took me my 1 hour lunch break at the dealership to change the one on my GXP.

I don't even like working on cars at home any more.

Leon

[repinS]

First time through at home without a lift took me most of the weekend.

Once I got it figured out, I could do a mount in 2-3 hours.

[PontiacFan]

It only took me my 1 hour lunch break at the dealership to change the one on my GXP.

Holy crap, I'm gonna come over & buy you lunch sometime to do mine!!!

[samples08]

To be honest when I changed my front mount over too the hockey Puck style I can never get the front of the engine high enough clearance to get the new mount into place with a floor Jack it took me awhile til I got my cousins engine hoist to pull the motor up after a few minutes I had the new mount in place and was done what I could never achieve with a floor Jack I achieved in 30 mins with an engine hoist but looking back on it now I probably could have done it faster had I not put the car on ramps in the first place but hey live and learn right