Broken Motor Mounts

[George B]

25847739, I paid $100ea at Rock Auto last April

That ship has sailed…

ACDELCO 25847739 Motor Mount | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

 

[PatDTN]

When I swapped engines last I removed the front wheel and plastic wheel well liner. That made accessing the mount much easier than when I replaced the mount before. Gave enough better access to make the extra work worthwhile.

 

[davidl13]

Change both sides with H3 motor mount pt# 25847739​

Is this the correct part number for the 2009 Yukon? And what is the part number for the upgraded 3rd mount on the cross member/tranny mount?

Thanks in advance

 

[donjetman]

2wd, 4wd, awd?

Here's all the part #s I used on our 2007 awd 6.2L Denali:
Changed all four O2 sensors, two # 213-3533, $58ea, & two # 213-3538, $53ea
Changed knock sensors, two# 213-1576, $11 ea
Changed both differential mount brackets, GM# 23104735 & 6
Changed both motor mounts (2), GM# 25847739, $100 ea
Changed tranny mount, GM# 15840278, $41
Changed trans pan ATF (6 qts) ACDelco Dexron6 #10-9395, $39
Changed trans filter GM# 24236933, $26
https://www.tahoeyukonforum.com/threads/front-differential-mounts.120260/page-3#post-1676685

 

[davidl13]

2wd, 4wd, awd?

Here's all the part #s I used on our 2007 awd 6.2L Denali:
Changed all four O2 sensors, two # 213-3533, $58ea, & two # 213-3538, $53ea
Changed knock sensors, two# 213-1576, $11 ea
Changed both differential mount brackets, GM# 23104735 & 6
Changed both motor mounts (2), GM# 25847739, $100 ea
Changed tranny mount, GM# 15840278, $41
Changed trans pan ATF (6 qts) ACDelco Dexron6 #10-9395, $39
Changed trans filter GM# 24236933, $26
https://www.tahoeyukonforum.com/threads/front-differential-mounts.120260/page-3#post-1676685

2009 Tahoe LTZ / z71, 5.3 4x4

 

[77mercury77]

I've done a couple sets of these now on various Denalis with 6.2L. I found that you can really make it easy on yourself by removing the tire for the side you are working on. After the truck is secure, you can use a floor jack to lift gently with a wood block on the exhaust down pipe. This will allow for that "little extra" room that seems to be needed to wiggle them out. First set, cussed all the bad words......second set figured out the jack idea and had both sides done in less than an hour.

I am going to be doing both sides on a 2010 Escalade ESV. Is pushing up on the cats better than the rear side of the oil pan? Both seem risky. Oil pan/pickip deformation and damaging the pan seal vs craking the exhaust tubing and shearing the flange bolts. Which is best in terms of lowest risk and highest chance of success?

 

[Geotrash]

I am going to be doing both sides on a 2010 Escalade ESV. Is pushing up on the cats better than the rear side of the oil pan? Both seem risky. Oil pan/pickip deformation and damaging the pan seal vs craking the exhaust tubing and shearing the flange bolts. Which is best in terms of lowest risk and highest chance of success?

I used a block of wood under the oil pan and it went fine. 2012 GMC Yukon XL Denali.

 

[iamdub]

I am going to be doing both sides on a 2010 Escalade ESV. Is pushing up on the cats better than the rear side of the oil pan? Both seem risky. Oil pan/pickip deformation and damaging the pan seal vs craking the exhaust tubing and shearing the flange bolts. Which is best in terms of lowest risk and highest chance of success?

Oil pan is cast aluminum and would crack before it deforms. Having said that, it's a structural part of the bottom end. As Dave said- a block of wood on a jack is fine. I'd like to add that I replaced one side at a time. Having one side secured when jacking it up makes the engine roll to the side a little, giving a hair more working space.

If you still would rather not use the oil pan, there are blocks sticking out from the engine block that you can put a short length of lumber, like a 2x4 under and jack it up with that.


It's the "cube" jutting out under cylinder #7 in this pic. There's one under cylinder #8, too:

 

[B-train]

I am going to be doing both sides on a 2010 Escalade ESV. Is pushing up on the cats better than the rear side of the oil pan? Both seem risky. Oil pan/pickip deformation and damaging the pan seal vs craking the exhaust tubing and shearing the flange bolts. Which is best in terms of lowest risk and highest chance of success?

Along with the other replies, just be gentle. All it takes is a little upwards pressure to relieve the mount. I went with exhaust because it put more emphasis on the side I was working with instead if lifting the whole motor from the pan (the pans are pretty tough FYI, a board on a jack is no issue).

Again, just a little finesse to get the job done. You'll know when you have the right amount........baby steps (or pumps)

 

[alpha_omega]

I am going to be doing both sides on a 2010 Escalade ESV. Is pushing up on the cats better than the rear side of the oil pan? Both seem risky. Oil pan/pickip deformation and damaging the pan seal vs craking the exhaust tubing and shearing the flange bolts. Which is best in terms of lowest risk and highest chance of success?

I have a 2011 Denali AWD and I used a block of wood under the exhaust. Granted I had recently replaced the manifold, the gaskets and the hardware, so I wasn’t worried about things being loose. I’ve done the oil pan method in the past, but would rather not put that much stress on it and like @B-train said, going with the exhaust route you get a more focused lift on the specific side you’re working on.

 

[dkmoneypit]

For my 09 Yukon I used a non fluid filled mount GM part #25847739. It was a pain to replace but I wont have to worry about it failing again. I believe this for the H3 Hummer.

 

[alpha_omega]

For my 09 Yukon I used a non fluid filled mount GM part #25847739. It was a pain to replace but I wont have to worry about it failing again. I believe this for the H3 Hummer.

Do you have AWD or RWD? Which lifting method did you use? Also did you pull the wheel well splash guards and starter motor? Not that it still isn’t a pain in the @$$ to replace (esp that passenger side), but each method has its perks and the different drive styles play a role as well.

Edit: I meant to write AWD or 2WD, not RWD. Damn auto correct.

 

[dkmoneypit]

Do you have AWD or RWD? Which lifting method did you use? Also did you pull the wheel well splash guards and starter motor? Not that it still isn’t a pain in the @$$ to replace (esp that passenger side), but each method has its perks and the different drive styles play a role as well.

I have the RWD. I only did the drivers side. I watched a you tube video. Carefully jacked up on the motor. Mine original oil filled went out at around 125k miles. You really shouldnt need to do the passenger side as the drivers side is the side that handles all the motors torque pulling up against the frame. Passenger side the torque pushes down against the frame. Back in the day most of use that used to race our cars around would use either a chain or a solid mount on the drivers side only.

 

[alpha_omega]

“Shouldn’t need to” or “probably should anyways” since you're already in there?

 

[OR VietVet]

You have a pair of motor mounts. You should do both when replacing. You have a pair of brake calipers. If one locks, you should still replace both calipers.

You can get away with replacing one front seat if one goes bad because it is not something that is designed to work in pairs.

Maybe I am over thinking it but that is the way I have worked on vehicles over the years.

When I am working on customer vehicles and I am doing a timing belt, I insist on doing the water pump if is timing belt driven, leaking or not. I highly suggest the cam and crank seals too but do not draw the line in the sand on those because I don't touch those during a timing belt replacement but do touch the water pump and we all know that if I touched it, I own it, in the customer's eyes.

 

[dkad260]

You have a pair of motor mounts. You should do both when replacing

Agreed.

Replacing the LH mount fixed the engine lifting off the mount.

Replacing the RH fixed the vibration at idle as that's the load side. The fact it was pretty much completely collapsed and hard as a rock also played a part...lol

 

[Monz11]

I said F U to the OEM mounts and went with the Atomic solid motor mounts........alittle vibration is well worth it. Plus they have a "can't break them warranty"

SAME. ATOMIC MOUNTS ROCK!!

 

[Writefast]

So is there not a better after market option? ::edited for never mind. lol. ::

 

[CMoore711]

I'm 90% the drivers side motor mount has failed on my '13 ESV. Was starting to see some fluid leak onto my driveway which looked to be coming from the front diff potential power steering pump area. This coincidently occurred after doing some fluid maintenance on front diff, transfer case, and transmission fluid. Checked fluid levels on all items and the levels were exactly where they should be and what I filled to. Head scratcher, WTF is this reddish oily like fluid in my drive way?!?

Over the course of the next few weeks I start to develop a slight "clunking" from the front end commonly happening when accelerating after a complete stop. Add the occasional random vibration while idling though inconsistent I feel it at times and I've landed on the drivers side motor mount failing at minimum.

These Hummer H3 OEM Motor mounts GM 25847739 have gone up significantly in price compared to what some of you found them for a year ago. Best price is $258/ea. from rockauto. So if doing the job and replacing the pair you're in for $516 plus a little shipping.

These atomic fab mounts look like very nice solid pieces and are a good bit cheaper now (as a pair) compared to a pair of the Hummer H3 mounts:

07-13 GMT900 Poly Motor Mounts - Atomic Fabrication

These are POLY motor mounts that fit 07-13 GMT900 GM LS-equipped trucks including Silverado, Sierra, Tahoe, Yukon, Yukon XL, Suburban, Denali, and Escalade. They are a direct bolt up using factory hardware. All of my mounts have a lifetime warranty.

atomicfabandperformance.com

My concern would be additional NVH.
Anyone have experience with the Hummer H3 GM OEM motor mounts vs. original stock ones?
Anyont have experience with the Atomic Fab motor mounts vs. the original stock ones?

 

[dkad260]

FWIW, I hear the Hummer mounts are robust, but some mention they just don't absorb as much vibration as the OE, but only slight differences.

Mine lasted almost 10 years, so I felt that added smoothness was worth it even though I can't compare them, just word of mouth.

So for less $$, I went OE..about $110- 120 shipped from Rock Auto.

When stopped at a light, you can hardly tell the engine is running.

Just my $.02, YMMV.