Front differential mounts

[Glisella]

Went to replace bushings in the mounts of my 08 Yukon XL Denali, after messing with the bushing for 5 minutes in 90 degree heat and seeing the rust on the mounts I said no, and placed order through RockAuto for both new mounts with bushings to be delivered tomorrow. Ground was $7 and overnight was $16. Will update once I get new mounts in. There are the original mounts with 225K miles on them. I had developed a clunk and after recently replacing all front suspension items I figured I'd do these next. Will see if it solves it and if not...at least I have new mounts lol.

 

[Glisella]

One more post - while top of mind and tools still out:

Nuts holding passenger side of diff to mount: 21mm

Bolts holding differential to driver side mount: 18mm

Both sides mount bolt heads: 18mm
Both sides Differential mount nuts: 16mm

 

[gooffeyguy]

How hard of a job/how long did it take to get the mounts out?

How much were the new mounts?

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[Glisella]

How hard of a job/how long did it take to get the mounts out?

How much were the new mounts?

Sent from my SM-G930V using Tapatalk

Overall 1.5 hours to remove.

Hardest part was getting my 16mm flex head ratchet wrench onto the four bolt heads holding the mounts in. The front passenger side I went through opening hear wheel well, front driver side I went down through engine bay, it's beneath steering shaft. Other two back bolts I was able to get at fr beneath vehicle. Maybe a socket and ratchet would be easier, I shockingly just found out I don't have one that size.

Both mounts were same price, $75.79 for AC Delco and then I got 5% off that. Part numbers are 23104736 for the driver side and 23104735 for passenger side. Again, these are for AWD on 08 Yukon XL Denali.

 

[ls1frc]

Did it fix your clunk?

 

[Doubeleive]

one of mine on my 2012 Denali had pretty much disintegrated the rubber just crumbled away

 

[Glisella]

Did it fix your clunk?

New parts won't arrive until today. Will let you know.

 

[Glisella]

one of mine on my 2012 Denali had pretty much disintegrated the rubber just crumbled away

That's the way two of my bushings were. The rear driver side and front passenger side.

 

[ls1frc]

New parts won't arrive until today. Will let you know.

Great. I've had a clunk since I got the truck with 105k on it coming to a stop. Replaced motor mounts and didn't fix it. Hoping it's this.

 

[Joseph Garcia]

I recently replaced my front differential mounts, due to a clunk that I could not get rid of, even after I replaced the slip yoke. The clunk disappeared after replacing the mounts and bushings, and I'm confident that you will achieve the same result.

There is my thread on the topic:

https://www.tahoeyukonforum.com/thr...-not-the-drive-shaft-slip-yoke-solved.119545/

 

[Glisella]

Installed the new mounts today, about 40 minutes to put both mounts on and then mount up the differential on both sides.

Took it for a ride and clunk I had is gone completely. To best explain it, intermittently when I'd get on it I'd get this clunk. Didn't matter if 15 mph or 75. If I'd give it some gas to pass someone on highway or push down on pedal to go up a hill it would happen. Sometimes I'd get it when braking hard to a complete stop, like if I was going 40 and came up to a light that changed to red quickly. As the vehicle would rock back from the full stop I'd hear the clunk. It makes sense to me now after seeing condition of old mounts and how they hold the differential, when giving gas or the sudden deceleration to a stop causes movement with the rubber bushings shot it was metal on metal and therefore clunk.

I'm happy for now. Another part coming next week to swap out.

 

[ls1frc]

That's great to hear. Going to do the same to mine.

 

[Joseph Garcia]

Isn't it GREAT not to hear the clunk? I also found that my driving habits had changed a bit to the more conservative side over the period that I had the clunk, in that I would try 'not' to do anything to make it clunk. Now, without the clunk, I am free to drive more spirited (and lose another 1+mpg on gas, but who cares).

 

[George B]

Isn't it GREAT not to hear the clunk? I also found that my driving habits had changed a bit to the more conservative side over the period that I had the clunk, in that I would try 'not' to do anything to make it clunk. Now, without the clunk, I am free to drive more spirited (and lose another 1+mpg on gas, but who cares).

The difference in my driving styles amounts to about 4-5 mpg. LOl!

 

[Glisella]

Isn't it GREAT not to hear the clunk? I also found that my driving habits had changed a bit to the more conservative side over the period that I had the clunk, in that I would try 'not' to do anything to make it clunk. Now, without the clunk, I am free to drive more spirited (and lose another 1+mpg on gas, but who cares).

Same, I was definitely driving differently to minimize the clunking.

 

[08grey]

Anyone ever try the moog equivalent?

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[Geotrash]

Sorry about the thread necro but I just finished this job on my 2007 Yukon XL Denali with 215K on the clock and wanted to provide a little more detail:

-The passenger side comes out relatively easily
-The drivers side takes a lot more finagling, but I found that if I left the mount-to-diff bolts on the passenger side off, and kept downward pressure on the diff itself (and sometimes rocking it up and down), I could eventually work the drivers side mount out toward the FRONT. The new one went in the same way the old one came out.
-For both, the front-most bolt must be held with a ratchet + long extension from above, so I needed my son to hold the ratchet while I loosened/tightened those bolts from below. The one on the drivers side required a short wobble extension on the bottom to fit snugly on the bolt head. For the rearmost bolts, I was able to hold the top of the bolt from below with a ratchet and a 15mm socket while loosening the nut.

It solved about 90% of my clunking when going from coasting to accelerating. There is still a small clunk but that's likely the transfer case as there's a ton of play in the chain. There used to be a bang with the clunk and the clunk was much stronger previously. Well worth the 90 minute time investment to do it. I used OEM AC Delco parts from Rock Auto.

 

[Joseph Garcia]

Sorry about the thread necro but I just finished this job on my 2007 Yukon XL Denali with 215K on the clock and wanted to provide a little more detail:

-The passenger side comes out relatively easily
-The drivers side takes a lot more finagling, but I found that if I left the mount-to-diff bolts on the passenger side off, and kept downward pressure on the diff itself, I could eventually work the drivers side mount out toward the FRONT. The new one went in the same way the old one came out.
-For both, the front-most bolt must be held with a ratchet + long extension from above, so I needed my son to hold the ratchet while I loosened/tightened those bolts from below. The one on the drivers side required a short wobble extension on the bottom to fit snugly on the bolt head. For the rearmost bolts, I was able to hold the top of the bolt from below with a ratchet and a 15mm socket while loosening the nut.

It solved about 90% of my clunking when going from coasting to accelerating. There is still a small clunk but that's likely the transfer case as there's a ton of play in the chain. There used to be a bang with the clunk and the clunk was much stronger previously. Well worth the 90 minute time investment to do it. I used OEM AC Delco parts from Rock Auto.

Thank you for posting. Great to read your success story and the detail on exactly how you executed the replacement project. This is great info for folks who need to replace these mounts in the future.

 

[petethepug]

This should be tied to a sticky and completed with motor mount replacement. Down the road this may show as a cure to short lived mounts we’ve blamed on what may have seemed like low quality mounts.

 

[Just Fishing]

these are really easy if you have the front axle out.

I did mine while i had the oil pan off, not too bad.

If you ever remove the front axle, remember to remove the cross member and use tiedown straps to compress the cv shafts so they stay out of the way.
That makes reinstalling the front axle a breeze.