Which Motor Mounts

[DragonSlayer1]

Hi All: Which motor mounts would you suggest for 2008 AWD GMC Yukon 6.2L. From what I'm hearing the stock ones are not being suggested.

Thanks

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

It is my understanding that the OEM motor mounts for your truck have a fluid-filled shock absorber built into them to reduce engine vibration in the interior, but in time, that shock absorber ruptures. I believe that some folks replace the OEM motor mounts with Hummer H3 motor mounts.

Other folks will chime in.

 

[donjetman]

Hi All: Which motor mounts would you suggest for 2008 AWD GMC Yukon 6.2L. From what I'm hearing the stock ones are not being suggested.

Thanks

Hummer motor mounts (2), GM# 25847739

 

[DragonSlayer1]

Thank you!

 

[swathdiver]

Hi All: Which motor mounts would you suggest for 2008 AWD GMC Yukon 6.2L. From what I'm hearing the stock ones are not being suggested.

Thanks

If you don't want any engine vibrations and don't dog the motor all the time, the factory fluid filled mounts are fine. But if you want something more durable and don't mind a little engine vibration at idle, the H3 mount that Don posted is the way to go. I run them both on mine. The Yukon gets the stock mounts and the 6.2s get the Hummer mounts!

 

[DragonSlayer1]

Thank you for the info. A large majority of the use of this Yukon 6.2 will be pulling a 28 enclosed snowmobile trailer amongst other family outings and trips. So not my daily driver. I'm looking to try and make some improvements for engine life longevity and overall performance. Having said that I will probably go with the H3 mounts. If you have any other suggestions for must have's on these rigs I'm all ears. I have notice lower oil pressure after driving for an hour or so, but it is not consistently low - which is an issue I've read about.

Thanks

 

[swathdiver]

Thank you for the info. A large majority of the use of this Yukon 6.2 will be pulling a 28 enclosed snowmobile trailer amongst other family outings and trips. So not my daily driver. I'm looking to try and make some improvements for engine life longevity and overall performance. Having said that I will probably go with the H3 mounts. If you have any other suggestions for must have's on these rigs I'm all ears. I have notice lower oil pressure after driving for an hour or so, but it is not consistently low - which is an issue I've read about.

Thanks

Once the oil is warmed up, the pressure on the gauge will usually be just shy of 40 psi, the bypass spring on the pump is 33 psi as our oil pumps deliver 1/3 more oil per rev than an iron block motor's pump to compensate for the increased tolerances in our aluminum engines.

How many miles? 6.2s have a tendency to break the #8 or #7 valve springs at around 165K miles. We see this more often with the oldest 6.2s, the 2007-2008 L92s but have seen it on the newer ones. If the motor gets hot, like a coolant leak, they have a tendency to drop a valve when the bronze guide fell out of place. There's a guy on here right now who probably has that issue. Having said that, not everybody experiences these things.

Run the truck on the severe service schedule except for the transmission. Change the fluid if all she does is tow to maybe every 10K miles or so. You can send out samples to Blackstone-Labs for analysis.

You can also beef up the valve body in the transmission and consider putting in a more stout torque converter. Not a higher stall, just stronger and improved parts. The weak link in our drivetrain is not the transmission but the torque converter.

You can check out Seth's upgrades to his Cadillac's transmission here:

6L80 Sonnax ZIP Kit, Pressure Switch rebuild, remote filter install, and fluid flush in 2013 Escalade ESV (Pic heavy)

Hello Gentlemen, Over the past few days, I have completed the following work to the 6L80 transmission in my 2013 Escalade ESV: -rebuilt the TECHM pressure switches using Sonnax parts -installed most of the Sonnax ZIP kit in the valve body -replaced the filter -installed a new pan with a drain...

www.tahoeyukonforum.com

 

[DragonSlayer1]

The rig has 139K miles on it. Any idea how I would know if a valve spring is broken?

Thank you for the info.

 

[Geotrash]

The rig has 139K miles on it. Any idea how I would know if a valve spring is broken?

Thank you for the info.

Yep. You would hear the piston fighting for territorial rights with a valve in one of those cylinders. It will be a short-lived dispute too, being settled in a matter of minutes or less.

 

[DragonSlayer1]

Hum. So would you suggest just replacing all of the valve springs to prevent a failure?

 

[Geotrash]

Hum. So would you suggest just replacing all of the valve springs to prevent a failure?

That's what I did with my 2012, but it was part of a cam swap so I needed to change them anyway. But, fear of one failing is part of what caused me to make the investment.

Lots of folks running around with 200K+ 6.2's that haven't broken a valve spring. So, at 139K I would say the odds are still remote, and will remain so even as you cross 165K some day, but they're also not zero.

150K is a nice time to do a bunch of heavy maintenance on these. This might be one of those items. Then, enjoy for the next 150K miles.

 

[petethepug]

I just replaced the OEM hydro mounts on our 09 6.2 @ 170k. Not recommended to wait that long but with AWD, it allowed $4k worth of work to be completed for $1.5k when I had the trans rebuilt.

With the trans pulled for either a 100k mi or later major service or replacement, the motor & trans mounts, front diff mount bushings and brackets and oil pressure switch are practically free labor. Did the pan gasket as well as F/R diff service too for that same $1.5k price.

One weak link in the 6.2 is that failure to replace all the drive train isolation bushings and mounts will result in short life’g the newly replaced ones mixed with old ones. We learned from our 08 YXL Denali. With the 09 6.2, the above parts were replaced with OEM GM, the same hydro mounts, all at once. We’re good for another 75k mi min now that it’s been done correctly.

 

[Monz11]

Yes, you could go with Hummer mounts, but these are well worth the upgrade, since you are pulling and no worries on future leaking. These are polyurethane, so no liquid filled crap. Atomic Fabrication and Performance the way to go!

Motor Mounts Archives - Atomic Fabrication

These are solid and polyurethane motor mounts for 99-18 GM trucks and TrailerBlazer SS SUVs

atomicfabandperformance.com

 

[Monz11]

Oh and this is the guy who makes the trucool trans cooler mounts, too!!

 

[petethepug]

How are you liking the poly mounts on your truck?

 

[12GMCYukon]

Trying to decide between the H3 mounts or the poly mounts. Is the vibration with the poly mounts really that bad?

 

[Foggy]

Trying to decide between the H3 mounts or the poly mounts. Is the vibration with the poly mounts really that bad?

Do the H3 mounts.. the solid poly ones have some bad reviews. H3 ones are the best
compromise between reliability and NVH.. I get just a bit more nvh with the H3's so
I bet the poly ones are fairly harsh

 

[the blur]

I got 80,000 from my OEM mounts. and I'll get 80,000 vibration free miles from the OEM oil filled replacements. Why anyone goes for solid mounts because they are worrying about 80,000 miles down the road.. ok. I won't have my truck at 80,000 miles down the road, it'll be someone else's problem. and if I do have it, ok, I'll spluge for another set of mounts.

 

[j91z28d1]

is 80k a lot of miles? cause if I don't see 300k on this thing I'm going to be bummed.

 

[Foggy]

I did them pro actively as I was adding a supercharger, beefed up trans, etc etc
I still have my 90k OE ones in a box and they are fine