Motor Mounts - 2008 Chevy Tahoe Z71 4x4

[89Suburban]

My d/s mount has been shot for a while. When I took it in to get a LCA and CV joint installed he just replaced it on his own whim. It added another $3-400 for the part & labor. He said they did it on the lift with the left inner fender removed.

I was kinda pissed he did it without asking but it DID need to be done and I kept putting it off. I have things I want to fix on this prioritized. I wanted to get the H3 mount but he installed a factory GM mount. SO, hell with it, it's done, and what a difference fells like a new truck. And so much more pleasant to drive. So I am glad it is done.

 

[Dustin Jackson]

My d/s mount has been shot for a while. When I took it in to get a LCA and CV joint installed he just replaced it on his own whim. It added another $3-400 for the part & labor. He said they did it on the lift with the left inner fender removed.

I was kinda pissed he did it without asking but it DID need to be done and I kept putting it off. I have things I want to fix on this prioritized. I wanted to get the H3 mount but he installed a factory GM mount. SO, hell with it, it's done, and what a difference fells like a new truck. And so much more pleasant to drive. So I am glad it is done.

@89Suburban I forgot to mention that I did end up using genuine Hummer H3 motor mounts, it looks great, the heatshield design on the H3 mount is smaller which makes it much easier to maneuver compared to the factory mount. $80 and change for the H3 mount on Amazon well worth it. The truck rides so much nicer with the new mount, apparently bad motor mounts attribute to a lot of rattling. My dashboard no longer rattles when driving down the road. I look forward to seeing how it rides with a new passenger and trans mount.

 

[TollKeeper]

I really need to check my mounts..

I will say.. The Passenger mount on the GMT800/900 are gravy compared to the GMT360 with a V8. I was quoted 2200 just to do the passenger mount. I didnt have it done!

 

[Dustin Jackson]

@wsteele @swathdiver @Fubar0715 I just replaced the passenger side motor mount, transmission mount, and sway bar bushings. This is what I did:
- Remove the front tires
- Remove the manifolds heatshields and fender liners.
- Remove steering shaft above motor mount if replacing driver side, undo the bolts and push it towards the firewall to remove it from the steering joint.
- Undo the bottom 3 bolts on both the driver and passenger side motor mounts, I bought a very VERY long 1/2 inch extension and I was able to get them from above using an impact drill. You can also get at some of these from the fenders.

- Undo the nuts and bolts for the transmission mount.
- Remove the starter, its 2 bolts and then I just let it hang down.
- Then jack up the drivetrain at the location of the drain plug using a 4x4 or 2 between the jack and the oil pan.
- At this point the transmission mount can be taken out so install the new Trans mount.
- Undo the top 4 bolts on the motor mounts. The metal shield on the mounts can be manipulated to make things easier, I started by opening the metal up to expose more of the bolts.

- On the driver side I was able to get at these 4 bolts from the fender using some deep sockets, a 1/2 inch swivel head ratchet, and a 1/2 inch "Flex Head Stubby Ratchet".
- Remove the driver side mount by compressing the metal shield and pulling it out the top where the steering shaft used to be. I was able to remove this one in 1 piece.
- Install the driver side mount using only the 4 top bolts.
- Remove the 4 top bolts on the passenger motor mount. I was able to get at 3 bolts from the fender using some deep sockets, a 1/2 inch swivel head ratchet, and a 1/2 inch "Flex Head Stubby Ratchet". The bottom right bolt I had to use my very VERY long 1/2 inch extension to get at it from under the steering rack, if you get on your back you can thread the needle of the steering rack, crossmember and diff you can see the last bolt.

- Removing the passenger motor mount was the most difficult part. I had to remove the 2 nuts on the mount to take it apart and make it easier to remove.
- Install the passenger side mount, the Hummer H3 mount is easier to install than the factory but this was still a very hard task. Use only the 4 top bolts.
- Lower the drivetrain and install the nuts and bolts for the transmission mount and the lower 3 bolts for both motor mounts. I had issues with the transmission not lining up to the mount holes so I just jacked up the drivetrain just a little bit and lined up the transmission to the trans mount with a screw driver through the bolt holes then I installed the trans mount bolts a few turns to keep it lined up then I dropped it back down again and finished tightening everything.

- Reinstall the starter.
- After that you just need to button everything back together, the manifold heatshields and the fender liners.

This job took me about 4.5 Hours. I used AcDelco part number 25847739 on both sides.

 

[wsteele]

@wsteele @swathdiver @Fubar0715 I just replaced the passenger side motor mount, transmission mount, and sway bar bushings. This is what I did:
- Remove the front tires
- Remove the manifolds heatshields and fender liners.
- Remove steering shaft above motor mount if replacing driver side, undo the bolts and push it towards the firewall to remove it from the steering joint.
- Undo the bottom 3 bolts on both the driver and passenger side motor mounts, I bought a very VERY long 1/2 inch extension and I was able to get them from above using an impact drill. You can also get at some of these from the fenders.

- Undo the nuts and bolts for the transmission mount.
- Remove the starter, its 2 bolts and then I just let it hang down.
- Then jack up the drivetrain at the location of the drain plug using a 4x4 or 2 between the jack and the oil pan.
- At this point the transmission mount can be taken out so install the new Trans mount.
- Undo the top 4 bolts on the motor mounts. The metal shield on the mounts can be manipulated to make things easier, I started by opening the metal up to expose more of the bolts.

- On the driver side I was able to get at these 4 bolts from the fender using some deep sockets, a 1/2 inch swivel head ratchet, and a 1/2 inch "Flex Head Stubby Ratchet".
- Remove the driver side mount by compressing the metal shield and pulling it out the top where the steering shaft used to be. I was able to remove this one in 1 piece.
- Install the driver side mount using only the 4 top bolts.
- Remove the 4 top bolts on the passenger motor mount. I was able to get at 3 bolts from the fender using some deep sockets, a 1/2 inch swivel head ratchet, and a 1/2 inch "Flex Head Stubby Ratchet". The bottom right bolt I had to use my very VERY long 1/2 inch extension to get at it from under the steering rack, if you get on your back you can thread the needle of the steering rack, crossmember and diff you can see the last bolt.

- Removing the passenger motor mount was the most difficult part. I had to remove the 2 nuts on the mount to take it apart and make it easier to remove.
- Install the passenger side mount, the Hummer H3 mount is easier to install than the factory but this was still a very hard task. Use only the 4 top bolts.
- Lower the drivetrain and install the nuts and bolts for the transmission mount and the lower 3 bolts for both motor mounts. I had issues with the transmission not lining up to the mount holes so I just jacked up the drivetrain just a little bit and lined up the transmission to the trans mount with a screw driver through the bolt holes then I installed the trans mount bolts a few turns to keep it lined up then I dropped it back down again and finished tightening everything.

- Reinstall the starter.
- After that you just need to button everything back together, the manifold heatshields and the fender liners.

This job took me about 4.5 Hours. I used AcDelco part number 25847739 on both sides.

Great job describing your method and steps.

 

[89Suburban]

Great job describing your method and steps.

Yeah man nice post!

 

[Dustin Jackson]

I've taken the Tahoe out a few times since installing the new mounts. I will say that after replacing the passenger side with the Hummer H3 mount there is a slight vibration at idle around 600RPM. After some research it looks like this is to be as expected from these mounts as they are a little bit stiffer. other than that the ride feels good, before the front end felt like it was full of luggage but now it feels like there is less moving and rattling around up from when driving around. Pretty happy with the results.

 

[mattt]

Been watching this thread for a while now. Is this motor mount access difficulty something unique to 07+ GMT900's or is this also an issue for 99-06 GMT800's? Going to be swapping engines soon and will be replacing motor mounts with new. Just wondering if this will affect my 04. Thanks.

 

[Dustin Jackson]

Been watching this thread for a while now. Is this motor mount access difficulty something unique to 07+ GMT900's or is this also an issue for 99-06 GMT800's? Going to be swapping engines soon and will be replacing motor mounts with new. Just wondering if this will affect my 04. Thanks.

@mattt If you are removing the motor from the Tahoe the motor mount will be easy to get to once the motor is out of the Tahoe. To remove the motor from the tahoe you just need to remove the bottom 3 bolts from each motor mount.

 

[mattt]

@mattt If you are removing the motor from the Tahoe the motor mount will be easy to get to once the motor is out of the Tahoe. To remove the motor from the tahoe you just need to remove the bottom 3 bolts from each motor mount.

Thanks. I figured that, but wasn't sure if this was only for 07+ or also the earlier 99-06. Good to hear the 3 bottom bolts are an easy remove.

I've seen in this thread some mention of swapping to a Hummer H2 or H3 motor mount. What is the rationale for making that swap?

Picking up motor mounts this week & leaning towards factory GM for these. Where is the best bang for the buck on GM motor mounts? If anyone has a pair of new or practically new motor mounts for sale, let me know. Thank you.