07 yukon denali motor mounts go bad every year

[chucksrt]

for the last two years the motor mounts have been going bad. I will be going on my 3rd set of mounts soon. I can't tell if it has a hard shift that is causing it or if its just the mounts making it seem that way? Has anyone had this issue?

 

[Foggy]

Do a search on the Hummer Motor mounts.. I think it's a sticky here.
The factory ones are a hydraulic type and fail easily.. but they are comfy !

 

[swathdiver]

for the last two years the motor mounts have been going bad. I will be going on my 3rd set of mounts soon. I can't tell if it has a hard shift that is causing it or if its just the mounts making it seem that way? Has anyone had this issue?

Chuck, have you changed all three each time? Are you using GM OE mounts or something else? How many passes down the 1/4 mile has the truck made? LOL

 

[PG01]

I was gonna say james, @swathdiver ......STOP BEATING ON IT!!!!
Lol

 

[mikeyss]

I changed mine out about a year ago with factory ones, and they still look new.

 

[Monz11]

check these out. I think Chris had listed these previously and I bought em and haven't had an issue, and I am jacking my motor to the gills and adding a Mag

https://atomicfabandperformance.com/product/07-14-gmt900-poly-motor-mounts/

 

[Meccanoble]

check these out. I think Chris had listed these previously and I bought em and haven't had an issue, and I am jacking my motor to the gills and adding a Mag

https://atomicfabandperformance.com/product/07-14-gmt900-poly-motor-mounts/

I almost bought a set. Great looking mounts and great company with amazing customer service. My H3 Hummer mounts didnt fail yet but if they do, this is definitely the way I'm going!

 

[huntster]

How can you tell the mounts are bad?

 

[chucksrt]

How can you tell the mounts are bad?

Clunking noise/feel when accelerating then coming off throttle or coasting and then accelerating.

 

[PG01]

How can you tell the mounts are bad?

Open hood and apply ebrake, start truck and with left foot holding brake pedal and trans in drive press gas pedal, While looking through windshield observe engine. If bad motor will lift up on driver side considerably, do the same in reverse to check passenger side mount.

 

[retiredsparky]

Pete,
Your idea for checking the motor mounts does work. I have used it before. However, I do question how being in reverse will check the passenger side. The torque the motor feels doesn't change direction, no matter the gear selection. The motor and tranny input shaft/pump/torque converter is still rotating the same direction when in reverse. The reversing happens in the tranny after the torque converter, so the engine doesn't know/feel any difference in reverse.

 

[avalonandl]

Clunking noise/feel when accelerating then coming off throttle or coasting and then accelerating.

That could also be a sliding yoke sticking on the trans output shaft. We had mine up on the lift and the mounts were ok but the yoke sticking caused a similar issue. If you accelerate slowly it doesn't make that clunk...

 

[91RS]

Are you using OEM mounts are cheap aftermarket ones? The aftermarket ones are cheaper for a reason. Use the GM ones and that will last much longer.

 

[Rocket Man]

for the last two years the motor mounts have been going bad. I will be going on my 3rd set of mounts soon. I can't tell if it has a hard shift that is causing it or if its just the mounts making it seem that way? Has anyone had this issue?

Read about 50-60 pages of this thread. You’re not alone. H3 mounts FTW.
https://www.tahoeyukonforum.com/threads/broken-motor-mounts.55790/

 

[91RS]

Open hood and apply ebrake, start truck and with left foot holding brake pedal and trans in drive press gas pedal, While looking through windshield observe engine. If bad motor will lift up on driver side considerably, do the same in reverse to check passenger side mount.

This doesn't always work for the right mount because generally the right mount will collapse and cause excess vibration to be felt. When accelerating the left mount gets pulled up and the right mount pushed down so unless someone is flooring it in reverse all the time the right mount will generally not break the same way as the left. The best way to test the right mount is to put it in drive and if you feel vibration then put it in neutral and see if it goes away.

 

[HACK BLOCK]

This doesn't always work for the right mount because generally the right mount will collapse and cause excess vibration to be felt. When accelerating the left mount gets pulled up and the right mount pushed down so unless someone is flooring it in reverse all the time the right mount will generally not break the same way as the left. The best way to test the right mount is to put it in drive and if you feel vibration then put it in neutral and see if it goes away.

I have this issue in my work car... I wonder if it's the mount

 

[wjburken]

Pete,
Your idea for checking the motor mounts does work. I have used it before. However, I do question how being in reverse will check the passenger side. The torque the motor feels doesn't change direction, no matter the gear selection. The motor and tranny input shaft/pump/torque converter is still rotating the same direction when in reverse. The reversing happens in the tranny after the torque converter, so the engine doesn't know/feel any difference in reverse.

Yes, and the transmission is bolted to the engine so as the transmission tries to turn the driveshaft in reverse and is resisted by the E-Brake, the torque will twist the motor/transmission assembly the other direction.

 

[PG01]

Pete,
Your idea for checking the motor mounts does work. I have used it before. However, I do question how being in reverse will check the passenger side. The torque the motor feels doesn't change direction, no matter the gear selection. The motor and tranny input shaft/pump/torque converter is still rotating the same direction when in reverse. The reversing happens in the tranny after the torque converter, so the engine doesn't know/feel any difference in reverse.

This doesn't always work for the right mount because generally the right mount will collapse and cause excess vibration to be felt. When accelerating the left mount gets pulled up and the right mount pushed down so unless someone is flooring it in reverse all the time the right mount will generally not break the same way as the left. The best way to test the right mount is to put it in drive and if you feel vibration then put it in neutral and see if it goes away.

Try it, tell me what your motor does in reverse on brake giving it gas.

 

[91RS]

This doesn't always work for the right mount because generally the right mount will collapse and cause excess vibration to be felt. When accelerating the left mount gets pulled up and the right mount pushed down so unless someone is flooring it in reverse all the time the right mount will generally not break the same way as the left. The best way to test the right mount is to put it in drive and if you feel vibration then put it in neutral and see if it goes away.