Fluid-filled motor mounts... GM ???

[Greg72]

With the recent decision to hardmount my tub/frame & rollcage, I was thinking of going with a motormount that might help to decouple some of the inevitable vibration from the engine and drivetrain.

Since I'm in the process of reworking the motormounts, if I'm going to make a change.... Now is the time to figure this out.

Does anyone know of a GM product that uses fluid-filled motormounts? Escalade, maybe? Looking for a few options and don't really know where to start.






-G

 

[Deuling]

Sounds like something to leak imo

 

[Greg72]

Sounds like something to leak imo

Like a Harley, right? ...but people still ride 'em.

Seriously though, based on how the new motor mounts are being configured, it would be ultra simple to swap a leaking one if it ever happened. You may have noticed I don't always take the simplest path to solve problems.


-G

 

[Fordum]

I cannot imagine putting liquid filled motor mounts on anything I drive willingly. Rubber does such a good job and lasts so long, I'd stick with it.

All the hydraulic ones I have ever seen leaked. Some as little as 30K. Plus they are expensive when you have to replace them.
And their failure mode sucks.

Having said all that, Caddy put(s) them on some of their V8s. Try 2002. I think that is the year of my friend's car.

He is on his third set.........

 

[Fordum]

Hmmm. That was probably not as much help as I thought. I double checked with Rockauto, trying to remember what kind of car it was.

Found the liquid filled mounts OK, but they are on an ELDORADO due to the cross mount engine.

Probably won't fit anything you are trying to mount.

 

[Greg Ducato]

When I bought a P30 Van front clip for the Cummins 4BTA it had , the Cummins used hydraulic mounts. These looked like something that might be easy to adapt, I have them stuck in a box somewhere.

 

[Greg72]

When I bought a P30 Van front clip for the Cummins 4BTA it had , the Cummins used hydraulic mounts. These looked like something that might be easy to adapt, I have them stuck in a box somewhere.

Interesting.

And given that it's a diesel application, they are designed for a heavy motor and lots of low-end torque.

Might need to look for an image online....


-G

 

[Smokinthehippies]

i'm pretty sure the 6.2 engines had them. which was what, the escalade, denali, all the special edition ones?

 

[Greg72]

OK, just some quick research on the 4BTSWAPS.com site yielded the following ideas:

Anchor brand liquid-filled motor mounts:

#2859
#2698
#2839
#2710
#2469

(Seems to be quite a bit of variation in the specific model people use, but they are relatively cheap to buy and are available through RockAuto, ORiellys, etc)

Lord Liquid-Filled mounts - Seem to be the Rolls-Royce of motor mounts, but seem to be impossible to buy in small quantities from conventional sources. Also seem to be priced about 10X higher than the Anchor stuff.....



-G

 

[TheBeast_88K5]

One of my instructors was a GM lead mechanic, for years.
He said that those hydro-mounts, are the WORST thing GM ever did to its high-end customers.

He said some Cadillacs would need them replaced every 20-30k miles.
Apparently, the design is just JUNK.

Food for thought.

 

[Greg72]

Hmmmm.......

20,000 mile service life would be about 25 years of driving at my current pace.


Perhaps the GM design is not worth considering, but there are certainly lots of cars and diesel trucks using fluid-filled mounts that are quite successful at reducing NVH while providing good service life.


-G

 

[454Sub]

I see the point he is getting at here, just trying to add a level of comfort to his ride. Everything being solid mounted will make for some vibes, which can get old over time. Is what he doing practical or easy? ummm, no, but neither is his entire build.

I know Cummins had some hydro mounts at some point, and they might be a better fit for what your dealing with than some GM mounts, as designed for alot more torque, and a hella more weight.

 

[sweetk30]

i replaced a front center motor mount few months ago on a 2001 acura mdx suv . it was hydrolic style and rubber if i recall .

60-70 bucks at local parts store.

and bottom was 4 bolt flat mount and top was 1 big stud i think .

 

[blazinzuk]

I don't think its worth the time or effort.

I solid mounted a guys body on a blazer, it made very little difference in the NVH of that truck.

Old trucks, we have a ton of wind noise, we have a ton of little vibes going on ( almost imperceptible) big off road tires aren't the best for NVH.

I think its too much work for too little gain.

Your motor is going to purr ( it better) so that will help a ton, a well tuned in motor.

I have changed the motor mounts in Jeeps for the fancy liquid filled ones from MORE and I really could not tell a bit of difference in NVH

Shoot I bet most people that ride in Kerts blazer would never realize that the entire drivetrain is solid mounted.

Conventional wisdom says that would vibrate you so much you coudln't see straight. Real world actions says thats not even close to true.

Besides you have a first gen so the top better be off most of the time. Once that happens any NVH isolation for anything pretty much goes out the window

 

[Greg72]

Eric,

I totally understand what you are saying.

The challenge is that "comfort" is a relative term and people's idea of what is acceptable differ wildly. To some people a 40-series Flowmaster is too quiet... to others it's completely deafening! Same with unbalanced Swampers on the highway..... some guys don't seem to even notice the vibration or howl of the tires, while it personally drives me nuts. That's one of the reasons I went with a radial tire(and a reasonably small one by modern standards) this time around on my build.

I guess my thought process is that if there is going to be any sort of harmonic vibration or noises either from the drivelines, transfercase, transmission or engine while rolling down the highway.... this would be my chance to decouple them from the rigid frame/body/cagework with for relatively low-cost and effort.... I suppose in classic fashion this is another example of a "Might As Well" rearing it's head just as I'm about to bolt on some traditional engine mounts and call it good.


-G

 

[454Sub]

Something I seen a few times done in some drag cars around here, as well as modified class stock cars is fellas cut a 1/4in thick strip of rubber the same basic size as the motor mount, drilled out holes, and sandwiched it between the mount and the pad on the frame. That could be something that could work for you, plus it might help with crossmember clearance problems that I have with my BB. Im sure its not going to stop all vibes, but it would help a touch, and still allow DIY or ORD or stock mounts in the stock spot. Just an idea.

 

[blazinzuk]

Eric,

I totally understand what you are saying.

The challenge is that "comfort" is a relative term and people's idea of what is acceptable differ wildly. To some people a 40-series Flowmaster is too quiet... to others it's completely deafening! Same with unbalanced Swampers on the highway..... some guys don't seem to even notice the vibration or howl of the tires, while it personally drives me nuts. That's one of the reasons I went with a radial tire(and a reasonably small one by modern standards) this time around on my build.

I guess my thought process is that if there is going to be any sort of harmonic vibration or noises either from the drivelines, transfercase, transmission or engine while rolling down the highway.... this would be my chance to decouple them from the rigid frame/body/cagework with for relatively low-cost and effort.... I suppose in classic fashion this is another example of a "Might As Well" rearing it's head just as I'm about to bolt on some traditional engine mounts and call it good.


-G

So true, as I get older I get less tolerant of things. Even though I to tend to put up with stuff for a while as I usually can't afford to fix some things.

The point I was trying to make is I don't think it would make a noticeable difference, even to someone who had no idea how these truck normally ride and drive like.

Although I certainly understand the mental aspect of it that when you start it up and go driving even if it would have been just as smooth with different motor mounts you know you have some nice ones and so it just seems smoother

I would stick with something that originally came on a high torque diesel though. Your motor won't be a slouch, and then if I did do that on the motor I would probably do it to the trans and t case too.


You know mine as well