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2006 gmc envoy_denali
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11 Posts
Discussion Starter · #1 ·
Hey All,
I am in the middle of the motor mount job on a 2005 TB 4.2L 4x4. The 4x4 gizmos seriously restrict the drivers side motor mount. I have the passengers side in, and I am wondering if now that it is 3/4" higher on the passengers side with the new mount, if that is not what is stopping the drivers side from lifting high enough. I am also wondering if I should put the old one back in temporarily to lower that side and lift the drivers side?
Another thought is loosening/removing the engine motor mount bracket (The top one with 4 bolts to give myself the small extra clearance needed?
Thanks,
Tom
 

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I un-bold everything, raise the engine with a JAAMCO press and can move it right or left to accommodate changing the mounts.

Both mounts ----> 30 minutes, tops.
This is a job I need done and have been reading a lot about it lately.

When you say unbolt everything - are you talking about the mounts and mount brackets or are you talking about things on top of the engine that might get in the way when it is raised (e.g. fan shroud, etc)?
 

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Hey All,
I am in the middle of the motor mount job on a 2005 TB 4.2L 4x4. The 4x4 gizmos seriously restrict the drivers side motor mount. I have the passengers side in, and I am wondering if now that it is 3/4" higher on the passengers side with the new mount, if that is not what is stopping the drivers side from lifting high enough. I am also wondering if I should put the old one back in temporarily to lower that side and lift the drivers side?
Another thought is loosening/removing the engine motor mount bracket (The top one with 4 bolts to give myself the small extra clearance needed?
Thanks,
Tom
I read it on the forums here but cannot remember where BUT...

there is a post out there somewhere of someone who said they loosened both motor mounts first. So, I think the point was that engine will raise better as opposed to having one side loose and one side tight.

I also read a lot of people had luck cutting/grinding a 1/4inch or so of the stud on the motor mount (there is room to cut above the threads). That saved a bit of room. I am guessing you did not have to do this for the passenger side?

This is a fix I REALLY need. But I do not want to take it to the mechanic - seems too costly although I havent asked. I am just sitting here waiting for my lumbar annular tear to heal.... 3 months annnnd counting.
 

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2004 chevy trailblazer_lt
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3,439 Posts
I can't help you with the technique, but I will advise you to use only the GM/ACDelco OEM motor mounts. Aftermarket ones are junk and will fail sooner rather than later.
 

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2006 gmc envoy_denali
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11 Posts
Discussion Starter · #6 ·
So hey guys,
I do have GM mounts. I removed fan, throttle body, air intake contraption, MAP and loosened the PCM. I got the bolts off the top and bottom of the mounts. .I jacked the motor with a block of wood. I have it all the way up with the only constriction being the shroud covering the top of the engine butting against the top of the engine bay. I got the passenger side out pretty easy because it was compressed. I then had to grind 3/8 off both sides of the new one to get the passenger side in.
Now I am trying all kinds of things to get the driver side out with the 4WD stuff in the way. I have slithered my hands in a couple ways and can move it around, I can pop the bottom bolt out of the bracket, but the angle is such that I can not pull it out with it being sandwiched between the brackets.
I am going out today to remove the passenger side and put the old compressed mount back in so that hopefully that 3/4 of an inch of compression on the passenger side will allow the driver side to lift more. I read of a guy on this forum that actually placed the engine jack more on the drivers side of the oil pan to force the engine to torque more towards the passenger side when it lifted.
I subscribe to ALLDATA DIY which is supposed to be the GM manual for the specific vehicle, and it throws a half a line blurb about removing the drivers side strut, and then removing the 3 bolts behind the strut that hold up the frame (bottom) motor mount bracket, I assume this is to get you more space to move the mount, Has anyone done that?
 

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2006 gmc envoy_denali
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11 Posts
Discussion Starter · #8 ·
Hey Metal Mike. They were. I actually looked them over quite a few times! I love the one on the bottom by TRQ who just says "The drivers side is a little more difficult" then he reaches in and pulls it out!
 

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2002 Chevrolet TrailBlazer LTZ 4.2L
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524 Posts
Hey Metal Mike. They were. I actually looked them over quite a few times! I love the one on the bottom by TRQ who just says "The drivers side is a little more difficult" then he reaches in and pulls it out!
I watched them myself before posting to at least make sure they were helpful and not fluff and got a kick out of that part. The TRQ videos are great for these videos and the dude that does them is always to the point.
 

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2006 gmc envoy_denali
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Discussion Starter · #10 ·
OK. The mounts are in. LOL. What an adventure! So the key for me on the 4X4 4.2L was all the tips above.......BUT......what worked for me was to break free the old mounts first, and leave the passenger side in and do the drivers side first!
My mistake was going for the easy one on the passenger side first, and putting in the new GM passenger mount. It really should NOT make a difference, but it did for me. The height of that new mount on the passenger side simply would not allow me to torque the engine high enough on the drivers side!
I started this morning removing the new taller passenger mount and actually cutting a 4x4 just smaller than the old compressed mount, and laying it in between the passenger side mount brackets where the mount should go.. This was to make sure I could jack the drivers side, and allow the passenger side to fall to a lower height......and not break any metal.
I then moved my jack to as far as it would go on the drivers side of the oil pan and lifted, and sure enough, the engine torqued up on the drivers side and down on the passengers side, and the drivers side mount popped right out.
I had already ground down the new mount for the passenger side, (I put the nuts on and ground the top nipple off and about 3/8 off the bottom) and I decided to try that one, and it slipped right in! Don't mess with success!
I then lowered the jack and tightened the drivers side mount nuts, as I expected that now that mount would act to hold down the drivers side for when I moved the jack to as far as I could to the passengers side of the oil pan and jacked it.
Sigh. When I moved the jack and lifted, the engine did lift pretty well........but the NEW (not shortened) mount would not slip in! Its like the new mount on the drivers side was so tall, it was just enough to allow the passenger side to lift!
So I am not proud by this point to tell you that I whipped out the cutting wheel, ground off the nipple on top, and 3/8 of the bottom (again with the nuts on) and slipped that motor mount right in and tightened it up. I used blue thread lock on both sides.
The main thing was watching all the videos you could and THIS forum. I got the trick about moving the jack from side to side and a little grinding from one of the other motor mound threads, as well as the tip about doing the drivers side first with the old compressed mount still in the passengers side.
Another thing for me was removing both front wheels, and putting the car on jackstands just a little higher than the car would sit with the wheels on. I was able to get to the bottom and top nuts with my Frankenstein compellation of universal joints and wobble extensions, and even use an impact tool to break them loose at that height. I used a small step ladder to reach in on the top. The slight jacking and wheels out of the way also allowed me to find every nook and cranny I could reach into from underneath to work on this situation.
 

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'05 TB 4.2 EXT
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6,192 Posts
Rule #639: Motor mounts --- do the hard one first.

Rule #1: NEVER DISCONNECT THE BATTERY. NEVER.
Rule #2: Obey all rules
Rule #3: Never bring a breaker bar if an impact gun fits.

PS --- I only read the first 15 words or so. I got tired of all the letters and stuff not being legible to my old eyes.

I lied --- I only read the first 10 words and assumed the rest were about the same problem --- did I miss anything?
 

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hey seacamper, would you recommend taking the wheels off vs. just rolling the car onto my little wheel ramps? Did you have much more mobility with the tires off?

and good job man, i am jealous and so it my stuttering envoy. way to bang out the job.
 

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2006 gmc envoy_denali
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Discussion Starter · #13 ·
Hey Dsport,
Yes. Honestly, with the wheels out of the way, and jackstands back behind my work, I was in the wheel wells and under the rotors A LOT during this adventure. I am ashamed to admit I forgot to disconnect the battery after all was said and done.
 

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thanks. what would have disconnecting the battery have done? There are a couple scary d00dz round these here parts that talk a lot about never disconnecting the battery and just the fuses you need because of some plastic parts behind that dash that get brittle each time (this is a quick run down from what I understand of it)
 

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2002 Chevrolet TrailBlazer LTZ 4.2L
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524 Posts
Whenever the battery is disconnected and reconnected, the HVAC systems goes into a full recalibration mode. The little plastic gears and their 20+ year old plastic teeth age and become brittle. During the recalibration procedure, the actuators are pushed to their furthest points to find the minimum and maximum sweeps. Flexing old plastic like this is a recipe for disaster. You'll get broken gear teeth, clicking behind the dash and issues with functionality. The 2 main actuators that routinely fail due to this are located way up and behind the dash and often requires the entire dash be removed to replace them. It can be a tight squeeze but it is doable.

This isn't some scare tactic but known information that has been experienced by many of us on the forum. I wish I had known this before disconnecting my battery, as I now have 2 clicking actuators behind the dash. There are a few know-it-alls running around the forum that say this is false merely because it hasn't happened to them. Yet.

Use this information how you'd like. Removing just the fuse for the component you are working on is safer and will not cause the HVAC relearn to happen.
 

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'05 TB 4.2 EXT
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6,192 Posts
Whenever the battery is disconnected and reconnect, the HVAC systems goes into a full recalibration mode. The little plastic gears and their 20+ year old plastic teeth age and become brittle. During the recalibration procedure, the actuators and pushed to their furthest points to find the minimum and maximum sweeps. Flexing old plastic like this is a recipe for disaster. You'll get broken gear teeth, clicking behind the dash and issues with functionality. The 2 main actuators that routinely fail due to this are located way up and behind the dash and often requires the entire dash be removed to replace them. It can be a tight squeeze but it is doable.

This isn't some scare tactic but known information that has been experienced by many of us on the forum. I wish I had known this before disconnecting my battery, as I now have 2 clicking actuators behind the dash. There are a few know-it-alls running around the forum that say this is false merely because it hasn't happened to them. Yet.

Use this information how you'd like. Removing just the fuse for the component you are working in is safer and will not cause the HVAC relearn to happen.
Well played, Mike. Kudos.
 

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2006 gmc envoy_denali
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Discussion Starter · #17 ·
Damn! I am GLAD I forgot the battery! Anyhoo, an update on the mounts.......smoooooth. I bought this TB about a month ago, and I noticed a little vibration, but I thought it was probably the hubs. For some reason, I had a brand new set of front hubs from my 4WD Envoy, so I bought the car thinking I would simply put those on and solve the problem. When I took the wheels off to do the job, there was no indication the hubs were bad, so after reading these forums, I realized changing the mounts was a good idea. I had no real positive proof it was the mounts, other than rocking the motor and watching the mounts, and that was inconclusive to me, so I was like......how hard can this be? After all is said and done I am real glad they are in, and the vibration is gone! I did the catalytic converter at the same time but that is my next thread!
 
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