Need some advice - motor mount problem.

[Michro]

So I started noticing a loud vibration inside the cab of my H3. Went to the dealership and they said the motor mounts need to be replaced, but it's like $600 to do it there. Does anyone know if it's an easy job to do on your own? I seem to hear that you can get a block of wood along with a jack to push the engine up, take the mounts out, and replace them. I'm not sure how safe that is for a beginner. Any help?

 

[4speedfunk]

Yeah...I've done it that way on numerous old Chevys...its not a problem. You'll want to jack the motor up from the damper (not the oil pan). A better method is to use an engine hoist and lift it from above but, either way should work...its not rocket science. Just make sure you don't bend or dent the pan. I can only assume it would work on an H3...can't really say I've ever noticed the motor mounts.

 

[mkmcgreg]

So I started noticing a loud vibration inside the cab of my H3. Went to the dealership and they said the motor mounts need to be replaced, but it's like $600 to do it there. Does anyone know if it's an easy job to do on your own? I seem to hear that you can get a block of wood along with a jack to push the engine up, take the mounts out, and replace them. I'm not sure how safe that is for a beginner. Any help?

Does it rattle with a cold start up? Mine does that but it hasn't bothered me that bad yet. Always wondered if I had a bad motor mount or that was just a characteristic of the I-5

 

[Michro]

Does it rattle with a cold start up? Mine does that but it hasn't bothered me that bad yet. Always wondered if I had a bad motor mount or that was just a characteristic of the I-5

That's how mine was at first. To be honest, I've postponed this thing for way too long due to the cost of fixing it. Since it first started, the vibration is worse on certain days/temps. Definitely don't want to take it back on any trails until I get this fixed.

 

[alrock]

I've replaced both motor mounts twice but fortunately those were warranty repairs

 

[poncho1965]

Does it rattle with a cold start up? Mine does that but it hasn't bothered me that bad yet. Always wondered if I had a bad motor mount or that was just a characteristic of the I-5

Mine does, sounds like rod bearings but doesn't last long...


Mike

 

[amrg]

Ive replaced mine twice too, on warranty repairs. I now need to replace it a third time. Been ignoring it for a couple of months now, but the vibration just keeps getting worse and worse (over a long period of time offcourse). Revving the engine up just abit above idle kills the issue at standstill in my case.

 

[4speedfunk]

Save your old motor mount parts (I assume they come off in pieces). They might be something to use as a mock-up to create a urethane mount. I didn't realize there was such an issue with them. After years of hot-rodding...I'm sort of a fan of solid mounts. True, they shake the whole car....but, you only have to change them once. Depending on what you end up with after you remove yours...you might be able to weld some 1/4" plating to them and make them solid.

 

[Michro]

Save your old motor mount parts (I assume they come off in pieces). They might be something to use as a mock-up to create a urethane mount. I didn't realize there was such an issue with them. After years of hot-rodding...I'm sort of a fan of solid mounts. True, they shake the whole car....but, you only have to change them once. Depending on what you end up with after you remove yours...you might be able to weld some 1/4" plating to them and make them solid.

Good thinking. I definitely want to get into more modding. Just need a garage :-\

 

[Michro]

Does anyone know how unhealthy it is for the engine? I've been ridin' mine for some months like that.

 

[Michro]

Also, if anyone can find a video of someone doing this, that would be awesome.

 

[alrock]

It's unhealthy for the truck to have the engine rocking back and forth when you have a broken motor mount. It can lead to other broken parts. For example, on the H1 it leads to the fan hitting the shroud and flying pieces of plastic. I've not seen an H3 video for the motor mount, but the idea is pretty similar across many vehicles. There are many YouTube videos on the subject. Here's an example of what's happening in your truck with a broken mount. The engine should not move like this. https://www.youtube.com/watch?v=RVwZHn6ISr4

 

[Michro]

It's unhealthy for the truck to have the engine rocking back and forth when you have a broken motor mount. It can lead to other broken parts. For example, on the H1 it leads to the fan hitting the shroud and flying pieces of plastic. I've not seen an H3 video for the motor mount, but the idea is pretty similar across many vehicles. There are many YouTube videos on the subject. Here's an example of what's happening in your truck with a broken mount. The engine should not move like this. https://www.youtube.com/watch?v=RVwZHn6ISr4

Whoa, I don't think mine is that bad. But overall, I feel confident doing this myself. I just need the parts and a few tools.
http://www.rockauto.com/catalog/x,carcode,1441261,parttype,5552,a,Search+for+BALKAMP

 

[alrock]

If you want OEM ones, vs. aftermarket, here's a set. http://store.gmpartshouse.com/parts...e=HUMMER&model=H3&submodel=&vehicleid=1441262

I don't know anything about the aftermarket ones; just giving you an alternative with one from one of our forum sponsors.

 

[Reloader]

I would definately get the oe ones from GM as the aftermarket ones can have a harder rubber used in their construction causing some vibration to get through. The softness of the oe ones could explain their short life if the vehicle is offroaded more than most of the mall cruisers. It is possible that the Rock Auto ones are made by the same vender that makes them for GM and just reboxes them for who ever.
I see that the I-5 engine has 2 balance shafts driven off the rear of the crank shaft by chains to smooth out the engine pulses.
Only minor hand tools should be required to replace the mounts. I see that the mounts are captive so the engine shouldnt move all that much when they fail. Also take a look at the rear mount between the trans and transfercase to make sure its still in good shape. That one is real easy to change out if necessary.

 

[Michro]

I would definately get the oe ones from GM as the aftermarket ones can have a harder rubber used in their construction causing some vibration to get through. The softness of the oe ones could explain their short life if the vehicle is offroaded more than most of the mall cruisers. It is possible that the Rock Auto ones are made by the same vender that makes them for GM and just reboxes them for who ever.
I see that the I-5 engine has 2 balance shafts driven off the rear of the crank shaft by chains to smooth out the engine pulses.
Only minor hand tools should be required to replace the mounts. I see that the mounts are captive so the engine shouldnt move all that much when they fail. Also take a look at the rear mount between the trans and transfercase to make sure its still in good shape. That one is real easy to change out if necessary.

Thanks I appreciate it. From what I gather, I'm going to want 2 triangular jack stands, a jack so that I can push the engine up, then a ratchet to take the mounts off and replace them. Should be a quick fix. I'm new to doing anything mechanic, so this is a good starting point for me as far as getting to know my way around my engine. Can't believe I've had my hummer for 5 years and am just now wanting to put it to good use! No more mall cruisin'.

 

[Michro]

Ordered the mounts today from the oem site. Thanks for showing me those. Will be installing as soon as they arrive along with some Pulstar spark plugs. This forum is restoring life into my rig!