Broken Motor Mounts

[iamdub]

Here I am about to start a thread /question of “Motor Mount broke again?!”

Replaced with Generic mount professionally 6 months ago...

And “thud” is back. Much better than the blown ones I bought the truck with, but still, did it go bad already??

I’ll have to read the book of this thread for answers when I get home from work.

This time though I’ll be replacing myself... just which brand will survive my right foot.

Also... how much serious long term damage can it cause if hold off a bit?

X 1,276,382 on the Hummer mount. I have "an apparently overly-sensitive throttle" so mine clunked hard may times during my drives. Obviously, it'll get worse the longer you leave it. The extra movement can put additional stresses elsewhere on the drive train and I think there has even been reports of a cracked bellhousing or trans tail shaft. The broken mount's slop is limited by the pin that goes through it. Repeated slams on it will start to bend and wear the pin until it snaps. Don't let it get that far.

 

[iamdub]

Yes very broke.

I'm getting a clunk with my H3 mounts. I'll report tomorrow if they went bad. I have poly mounts to fall on if so!

You sure it's the mount(s)? If so, did you use OEM or aftermarket?

 

[tgui]

You sure it's the mount(s)? If so, did you use OEM or aftermarket?

OEM H3s. Trans and engine tuned 6.2 for hard fast shifts.

Just went out to check since I couldnt wait. All is OK. I think its driveshaft clunk.

 

[Awfiretto]

Thank you all - H3 mount 25847739 Expressed from Rock Auto $95. Only doing the driver as the passenger was just replaced 6 months ago, and the reverse brake torque test shows little movement and no clunk, the clunk just started. I've not "Taken it easy" on her since they were replaced. I have got the engine running strong, sparks/wires/MIT Airraid tube, so while it's mostly stock it has some grunt. Combine that with the occasional 4 wheeling adventure... "flooring it in 4 wheel" I can see where the stock liquid filled mounts wont stand up to it. It is a shame GM would sell a truck rated to tow 7500 and then have mounts that bust under reasonable use.

The reply of the PPV maintenance techs using H3 mounts kinda sold me on it all... like really GM??? give a truck 330 hp and similar torque... put an engine mount fit for a 6 banger in it (eye roll).

The mount inst completely shot yet as it only clunks under 80% ish throttle. But the originals definitely were, the "clunk" was more of a "Bang" and the engine was all over the place over bumps and throttle.

Rocket man... playing this song as I post, thanks!

Now to watch some vids on the easiest way to do the drivers side motor mount. Ill post back any findings of running only one h3 mount on drivers side and liquid filled on passenger. Thanks all.

 

[Awfiretto]

H3 mount arrived today’s, afeter a long days work, I was motivated to get r dun

Used the trucks jack, a 15mm socket with two tiny extensions, and a piece of old steel target I had laying around to complete the job. Plenty of writes and videos on how to do it so I’ll spare ya the details unless desired.

A pain... yes... but really not that bad, 2.5 hours and that includes test drive.

The h3 mount fit perfect, and easier to get in than it was to yank the Tahoe mount out.

Vibration is ever so slightly more... but really you can’t tell a difference. Solid feel, but again, ever so slightly more solid.

Happy and thankful for TYF and all the peeps here. Saved me 100s and,made my truck better than stock for 2.5 hours and $95 bucks. Thanks all. I was careful... used the bell housing of the transmission, and the trucks jack to lift the motor just enough. E brake on and hands clear the whole time. Rock test proved solid H3 mount in. Yes ... I know My steering boot... it’s on the list... which is pretty small now busted... can’t belive it’s only 6 months old gonna try and get money back from the warranty on it.

 

[Wolfbraid]

H3 mount arrived today’s, afeter a long days work,...

Glad to see this post... maybe I'll try mine this week, I've been staring at my mount for a month.
I'm a little worried about lifting the engine is jacking the bell housing ok?, did you do all the work from below?
or did you go through fender well too?

 

[iamdub]

I'm a little worried about lifting the engine is jacking the bell housing ok?, did you do all the work from below?
or did you go through fender well too?

You should be worried. Alex was VERY lucky to not have cracked his bellhousing.

When I did mine, I worked from underneath, through the fender well and from the top. You'd be going out of your way to make it more difficult by trying to stay in one spot.

 

[tgui]

Yes be careful.

Here is where I jacked up on my oil pan. Pine wood that deforms a bit. I have a trans jack too but thats probably not needed.

 

[Awfiretto]

Glad to see this post... maybe I'll try mine this week, I've been staring at my mount for a month.
I'm a little worried about lifting the engine is jacking the bell housing ok?, did you do all the work from below?
or did you go through fender well too?

I agree with others, if you have the time and a few more proper tools, it will be much less difficult. For me I only had last night after work, and have a 2nd car if needed for the next few days, so I decided to attempt it, knowing if needed I could run to Walmart for tools. I have to go back to work this morning and family coming this weekend... and in temp housing currently, the circumstances are extenuating for me.

Bell housing was fine; I used a piece of steel to spread the load across the ribs of the bell housing. If you have it, a jack and piece of wood would be ideal. Your not lifting the truck with it, just the engine about 2/3 inch at most. I was careful and lucky. I was able to do it all without lifting the truck. Not recommended, but doable if in a pinch... just don’t jack the truck up from the bell housing... and don’t jack the bell housing with a tiny point on the jack.

I did it all from the top, there was just enough space to look through the side fender with out removal to see the bolts... those 4 bolts on the block... that will be the most frustrating part. If you have a flex extension this will help significantly. I decided to try without more tools, figuring by the time I ran to Walmart to get one I’ll be able to struggle through in the same amount of time. Be CAREFUL not to damage the wires especially the tiny one for the wheel speed sensor.

Getting the old one out was a puzzle, but bending the heat Sheild a bit (no worries there because your not using that anymore) and fidgeting it around you can get it out. A step stool will help reach it all... laying on the engine bay hurts sometimes. I used a moving blanket to cushion it a bit.

Theres a couple more vids out there, but this one gave me the courage to attack it. You can see this guys struggle with it and know what to expect. I was expecting a PItA so I was able to stay calm.

I’ve been a backyard/street/diy/“out of necessity” mechanic since I was 15 (now 32) doing things the hard way because it was the only way to get to work. Over the past years I usually have much more time and proper tools/lifts to get the job done, but this time I didn’t. After spending too much to have shop install engine mounts just 6 months ago, I was determined to do it myself. I tapped into those past “hard time” experiences to get through this one.

At least now a days I have a cell phone that doubles as a mirror, and can stick in places I can’t see to record video/pics of what I’m trying to reach (helps a lot for the 4 bolts on the block).

If I could do this in parking lot, at night, with only a 15mm socket, 3” and 1” extension, a pair of channel locks, the jack that came with the truck and piece of steel, and my mechanics gloves were a luxury.... most anyone could do this with a little more time & tools.

*not advocating or recommending to do it the way I did, just sharing the experience for knowledge to all.

But I couldn’t have done it without Tahoeyukonforum.

 

[iamdub]

I agree with others, if you have the time and a few more proper tools, it will be much less difficult. For me I only had last night after work, and have a 2nd car if needed for the next few days, so I decided to attempt it, knowing if needed I could run to Walmart for tools. I have to go back to work this morning and family coming this weekend... and in temp housing currently, the circumstances are extenuating for me.

Bell housing was fine; I used a piece of steel to spread the load across the ribs of the bell housing. If you have it, a jack and piece of wood would be ideal. Your not lifting the truck with it, just the engine about 2/3 inch at most. I was careful and lucky. I was able to do it all without lifting the truck. Not recommended, but doable if in a pinch... just don’t jack the truck up from the bell housing... and don’t jack the bell housing with a tiny point on the jack.

I did it all from the top, there was just enough space to look through the side fender with out removal to see the bolts... those 4 bolts on the block... that will be the most frustrating part. If you have a flex extension this will help significantly. I decided to try without more tools, figuring by the time I ran to Walmart to get one I’ll be able to struggle through in the same amount of time. Be CAREFUL not to damage the wires especially the tiny one for the wheel speed sensor.

Getting the old one out was a puzzle, but bending the heat Sheild a bit (no worries there because your not using that anymore) and fidgeting it around you can get it out. A step stool will help reach it all... laying on the engine bay hurts sometimes. I used a moving blanket to cushion it a bit.

Theres a couple more vids out there, but this one gave me the courage to attack it. You can see this guys struggle with it and know what to expect. I was expecting a PItA so I was able to stay calm.

I’ve been a backyard/street/diy/“out of necessity” mechanic since I was 15 (now 32) doing things the hard way because it was the only way to get to work. Over the past years I usually have much more time and proper tools/lifts to get the job done, but this time I didn’t. After spending too much to have shop install engine mounts just 6 months ago, I was determined to do it myself. I tapped into those past “hard time” experiences to get through this one.

At least now a days I have a cell phone that doubles as a mirror, and can stick in places I can’t see to record video/pics of what I’m trying to reach (helps a lot for the 4 bolts on the block).

If I could do this in parking lot, at night, with only a 15mm socket, 3” and 1” extension, a pair of channel locks, the jack that came with the truck and piece of steel, and my mechanics gloves were a luxury.... most anyone could do this with a little more time & tools.

*not advocating or recommending to do it the way I did, just sharing the experience for knowledge to all.

But I couldn’t have done it without Tahoeyukonforum.

Amen. You did what you could with what you had tool- and time-wise.

Sharing what and how you did something should always be welcomed and appreciated. Not everyone does something the best or worst way. But, just truly knowing WHAT you are doing, best way or not, is valuable to yourself and others.

Now, when someone does something harmful or even life-threatening out of sheer stupidity, especially even after they were warned, that's a whole other story.