Broken Motor Mounts

[CobraKing]

I just got my poly mounts and am eager to install but worried about the vibration.
The drivers side oem mount is the mount I destroy every year or so and have to replace. I'm wondering if I should just install the poly mount on the drivers side and either stay with oem or h2 for the passenger side. Any opinions would be appreciated.

Sent from my SM-G950U using Tapatalk

Generally not a good idea to mix and match engine mounts. The polyurethane mount on one side will be too rigid and the engines vibrations will be channeled to the weaker durometer mount. In general the car might 'feel' like shit due to the imbalance.

I've got a Tahoe PPV which comes standard with the H3 mounts and others have them already so why not go with them?

 

[08grey]

My weak point on the oem mount it the cross bolt that holds the two ends together. Every time I change it this bolt is bent.

Sent from my SM-G950U using Tapatalk

 

[Mrsteef]

One thing I noticed with the h3 mounts is better gas mileage (now with new h3 mounts vs broken factory mounts). I’m not sure I would want to go with poly mounts after getting used to the slight vibrations I feel with the h3’s. If it were me I’d either go full poly or full h3. Half and half to me is kinda pointless. Quick side note also it’s alot easier to change them from underneath the truck (2wd) if possible. Passenger side just remove the starter and it’ll pretty much fall out.

 

[08grey]

I'm going to install the poly. Just need some free time.

Sent from my SM-G950U using Tapatalk

 

[tgui]

I'm going to install the poly. Just need some free time.

Sent from my SM-G950U using Tapatalk

Poly mounts will outlive your truck. They're great.

Post pics!

 

[randeez]

Btw...lol

They seemed to lower the engine quite a bit...went from headers tight on top to rubbing on bottom after putting them on.

 

[tgui]

Strange. I saw no height difference. It's hard to guage when stock mounts can be so ******.

Still, great install. I was amazed when I could floor it and nothing rubbed or moved

Post vids!!

 

[tgui]

I just drove my Denali with the h3 mounts. No more vibration than with bad oem mounts.

 

[iamdub]

I'm looking forward to getting mine. Two OEM H3 mounts and a new OEM Tahoe trans mount should be delivered tomorrow.

 

[Ilikemtb999]

Anybody find them for less than $80 each? Seems to be the going rate.

 

[iamdub]

Anybody find them for less than $80 each? Seems to be the going rate.

The cheapest I found and where I got mine was from Rock Auto at $76.79 each. I have an Amazon Prime account and, even though shipping would've been free, RA's total price with shipping beat Amazon's price. Also, Amazon would've had to drop ship them from the supplier and they wouldn't have been available until sometime this month. On top of that, RA has a 5%-off discount code. I got two H3 mounts and an OEM transmission mount (currently $17.89) delivered in 3 days for about $176.

Installed them last night and couldn't be happier.

 

[tgui]

The cheapest I found and where I got mine was from Rock Auto at $76.79 each. I have an Amazon Prime account and, even though shipping would've been free, RA's total price with shipping beat Amazon's price. Also, Amazon would've had to drop ship them from the supplier and they wouldn't have been available until sometime this month. On top of that, RA has a 5%-off discount code. I got two H3 mounts and an OEM transmission mount (currently $17.89) delivered in 3 days for about $176.

Installed them last night and couldn't be happier.

What shape was your trans mount in?

 

[iamdub]

What shape was your trans mount in?

I think it could've stayed. It wasn't torn, but the rubber was obviously aged and had some cracks in it. Compared to the new one, it was almost an inch shorter. Either the new one will settle a lot or the old one had squashed that much over time. For the additional $20 and 20 minutes of labor, I'd rather have ALL the powertrain mounts be fresh so everything is in or closer to it's originally designed location. Considering I'll be lowering it, having the tailshaft at it's intended height and angle can help with driveshaft, U-joint and pinion angles which will be more important when lowered.

 

[George Hoffman]

Well mine is a 2000 Z71, old body style. Both of my motor mounts are shot after a day of mudding. My mechanic says he has to drop the front differential and then lift the body, then lift the engine. Don't know where you priced the motor mounts but mine were only like 16 bucks a piece...

 

[tgui]

Well mine is a 2000 Z71, old body style. Both of my motor mounts are shot after a day of mudding. My mechanic says he has to drop the front differential and then lift the body, then lift the engine. Don't know where you priced the motor mounts but mine were only like 16 bucks a piece...

Uhhh, your mechanic is over selling what needs to be done. I did mine with diff in, engine slightly jacked up, manifolds removed on my back in my garage.

Hell, I bet I could do it with manifolds in but taking the starter out for the passenger side.

Edit, obs? Whoops missed that

 

[iamdub]

Well mine is a 2000 Z71, old body style. Both of my motor mounts are shot after a day of mudding. My mechanic says he has to drop the front differential and then lift the body, then lift the engine. Don't know where you priced the motor mounts but mine were only like 16 bucks a piece...

Doesn't matter if they were 5 cents a piece- they're nothing like GenIII/GenIV mounts.

 

[Rocket Man]

Well mine is a 2000 Z71, old body style. Both of my motor mounts are shot after a day of mudding. My mechanic says he has to drop the front differential and then lift the body, then lift the engine. Don't know where you priced the motor mounts but mine were only like 16 bucks a piece...

LMAO you new guys kill me. Do you realize where you are, in the 07-14 NBS area? Different animal.

 

[sneasle]

Can you folks help me out a bit? I'm working my way backward through this thread, and it looks like 25847739 is the PN for the H3 engine mounts. Are their other mounts that I should swap (tranny, etc) at the same time? If so, are their H3 version that work there as well, or should I go with original?

 

[Rocket Man]

Can you folks help me out a bit? I'm working my way backward through this thread, and it looks like 25847739 is the PN for the H3 engine mounts. Are their other mounts that I should swap (tranny, etc) at the same time? If so, are their H3 version that work there as well, or should I go with original?

The H3 mounts are for the engine only. There’s nothing wrong with the design of the original trans mounts and they rarely if ever fail however if you like there’s nothing wrong with replacing it too.

 

[iamdub]

Can you folks help me out a bit? I'm working my way backward through this thread, and it looks like 25847739 is the PN for the H3 engine mounts. Are their other mounts that I should swap (tranny, etc) at the same time? If so, are their H3 version that work there as well, or should I go with original?

That is the correct part number. It's the RH (passenger) side mount for an H3. You'll need two of them as that mount will fit both sides of our trucks. The trans tailshaft mount is the only other powertrain mount. As Mark said, it rarely fails but it certainly won't hurt to replace it. I wanted all my mounting points to be fresh and the trans mount was only $20 and took about 20 minutes to change. My original one had cracks in it but wasn't separating. There's really no lateral movement in that area to separate it, it really should just squash over time as it ages and settles. I'm sure all the extra movement from my blown engine mounts torqued on the trans mount to cause the rubber to split.