2015 GMC YukonXL- Fox Coilovers

[Cadi_Mike]

I’ll definitely keep you posted on how it goes. Love the look of both your old wheel/tire combo and the new one. My last few vehicles have had 20”+ wheels and non-trimming size tires with big lifts so this time I figured let’s change my look and go BIG tires and trim with a smaller lift.

On my last 16 Yukon Denali with MRC I saw a increase in ride quality when I went to the Monroe’s. I had it from mileage 0 brand new and I just never felt the MRC was great. The xineering rep told me he loved his Monroe’s and they were cost effective and I did like the way they rode after switching. Slightly softer ride and much better with the bumps on the road than my Magnetic factories. I even saw a 1” height increase up front after the installation of Monroe’s.

Fabtech makes a dirt logic coilover 2.5 specifically tuned for the Fabtech 3” kit which seemed like maybe even a better route than king or Fox 2.5.....but most people agree king/Fox > dirt logic but I don’t know how king/Fox compare to the tuned dirt logic 2.5. The dirt logic is also same price tuned as the king/Fox are without being custom valved/tuned. I love the idea of having name brand stuff on the vehicle but then I had to catch myself in not getting caught up in that bc of my end goals of having a soft riding 100% highway vehicle. And with my experience before of going to the Fox 2.0 on the last Denali proved spending the extra money resulted in me not being as happy as I was with just the Monroe’s and Fabtech strut spacer. I’m hoping I love the Monroe’s ride, but if it isn’t any better I will 100% be trying one of the 2.5 options for the front and back and do that within the 2021 year. The Fabtech rep was really pushing the tuned dirt logics but then realized my vehicle was a SUV and realized we have the strut/coilover factory strut and just flat out told me I would be just as happy with factory/Monroe strut and the Fabtech front kit. I respected he wasn’t trying to just “sell” me something. And I’m not scared to at least give the Monroe’s a try and assess from there. Just waiting on Fabtech to ship the kit and I’ll be able to chime back in. Their stuff is on 3-4 week backorder currently. Discount called and said my wheels and tires were in though so I’ll post pics of those when I pick them up to take them to the Suspension install spot.

Gotcha man sounds like a solid plan. Yeah I am not too sure why I don't love the Monroes, could be just personal preference. I only did the fronts by the way. Yeah I definitely can see the benefit of going custom valving in the 2.5s. I just reached out to a company, Accutune, to discuss further. I think that is the way I want to go, and after more research I want the FOX 2.5 with DSC as they have high and low speed compression adjustment. I think a properly tuned 2.5 shock for the vehicle and driving style would take the cake on matching your driving preferences.

I agree though, better to try an economical version if highway driving is the goal for ride style.

Here's a video on Accutune, if you haven't heard of them:

Excited to see what you go with!

 

[nick14226]

@Nokturnal , seeing as you've done all of it, a couple quick questions from when you had the 3.5 fabtech if you don't mind. I'm looking at that kit and the readylift. The 4" BDS is tempting but seems overkill and pricey for my 99% on the road driving Yukon. I had a 6" procomp stage 1 lift on my truck but the simplicity of these "budget" kits with diff drop has me intrigued. And the full lift came with it's challenges on my truck too, seemed like I was always chasing something that wasn't quite right.

When you added the lower strut spacers did you find the UCA's ever showing contact with the droop/bump stops? I sanded down the plastic inserts for my 2.5 suspensionmaxx and it's very close but that's factory stamped UCA's (realize the fabtech UCA's will create more clearance). And the decent amount of miles you put on, did you have to replace ball joints, CV boots, tie rods, anything?

As for the back and the 3" spring spacers. I've got 1" now and didn't notice any left to right movement of the axle. I know from another thread you mentioned it with the 3", did you end up putting an adjustable panhard bar on yours? Thinking if I pulled the trigger on the fabtech I should have the panhard bar ready to go.

Thanks in advance!

 

[Tiki]

@Cadi_Mike Theres a couple of shops that offer “custom tuned” King shocks. Thuren has a great YouTube video showing stock vs tuned King shocks. I bought my non-tuned OE King replacements from Filthy Motorsports. It’s not hard to tune the shock, but I wouldn’t leave it to a off-road shop that doesn’t have significant experience. I’m going to have my Kings rebuilt (they have a lot of miles on them) and it’s looking like I’m going to have to ship them to Cali to get a competent rebuild.

https://www.thurenfabrication.com/07-gm-1500-custom-kings.html

https://www.filthymotorsports.com/

 

[Cadi_Mike]

@Cadi_Mike Theres a couple of shops that offer “custom tuned” King shocks. Thuren has a great YouTube video showing stock vs tuned King shocks. I bought my non-tuned OE King replacements from Filthy Motorsports. It’s not hard to tune the shock, but I wouldn’t leave it to a off-road shop that doesn’t have significant experience. I’m going to have my Kings rebuilt (they have a lot of miles on them) and it’s looking like I’m going to have to ship them to Cali to get a competent rebuild.

https://www.thurenfabrication.com/07-gm-1500-custom-kings.html

https://www.filthymotorsports.com/

Very good information. That is definitely the direction I will go. I am leaning towards the FOX 2.5 DSC as it has a little more fine adjustability with the low and high speed compression adjustment. But bottom line is I want to go with a "custom tuned" 2.5 shock. Most likely will be through Accutune as I am really impressed with their customer service, and shock knowledge in their Youtube and website. I'll post whatever I get eventually when I do.

 

[Nokturnal]

@Nokturnal , seeing as you've done all of it, a couple quick questions from when you had the 3.5 fabtech if you don't mind. I'm looking at that kit and the readylift. The 4" BDS is tempting but seems overkill and pricey for my 99% on the road driving Yukon. I had a 6" procomp stage 1 lift on my truck but the simplicity of these "budget" kits with diff drop has me intrigued. And the full lift came with it's challenges on my truck too, seemed like I was always chasing something that wasn't quite right.

When you added the lower strut spacers did you find the UCA's ever showing contact with the droop/bump stops? I sanded down the plastic inserts for my 2.5 suspensionmaxx and it's very close but that's factory stamped UCA's (realize the fabtech UCA's will create more clearance). And the decent amount of miles you put on, did you have to replace ball joints, CV boots, tie rods, anything?

As for the back and the 3" spring spacers. I've got 1" now and didn't notice any left to right movement of the axle. I know from another thread you mentioned it with the 3", did you end up putting an adjustable panhard bar on yours? Thinking if I pulled the trigger on the fabtech I should have the panhard bar ready to go.

Thanks in advance!

The Fabtech and ready lift are both solid budget lifts without sacrificing quality like you might on a Rough Country or similar. I only noticed very very minor rubbing on my Fabtech kit. I don’t remember it ever being an issue but remember seeing some scuff marks on my control arm if I can remember right. When I swapped from 20x9 0 offset to 20x10 -24 I noticed the scuff marks. But it def could’ve been from the 0 offset wheels bc the scuffs never got worse after the new wheels. But i never heard or noticed anything ever while driving. And now that I think about it....it may have even happened in a slanted elevated parking garage I lived in on my weekends in San Antonio. With ALL the mileage I put on it i never has any issues with the CV boots, ball joints, or rods. My 16 Yukon Denali had almost 240k miles on in it when I got rid of it. When I had the Fox 2.0 installed at about 215k miles I had the install shop go ahead and replace the ball joints ($48 apiece) since they were gonna be in there working around it. Figured since I had 75k+ miles on them might as well change them since so many guys reported failures at much lower mileage usage.


The 3” rear spring spacer definitely puts the rear axle in a bind, but nothing significantly noticeable. I would’ve never noticed but my first install was a nightmare in the Fabtech and the install place left something on my transmission disconnected that was clicking when I went over dips in the road. Some spot in Dallas was troubleshooting the install and mentioned it could be the rear end axle being in a bind and then i became aware of the slight shift. We later found that wasn’t the cause of the clicking noise and I ever added a pan hard bar to adjust the rear end. The BDS 4” kit included that adjustable pan hard but like you said it was overkill for what I wanted. I know with the 2” or less rear coil spring spacer the axle would look even better and I would say that it wouldn’t bother 99% of people. I’m it sure but I’ve seen people say with the 2” or less you don’t even have to add the supplied shock extensions and hardware in the Fabtech kit. But I’m not certain. I was even considering buying an extended rear shock for my rears but the Fabtech rep once again assured me that my ride quality would be no different if I did that vs. keeping factory shocks and using the hardware in the Fabtech box. I’m going to see if I lose rear height by swapping air ride shocks to Monroe. I already bypassed the air ride now before the install and my rear sits at 36.5” now to the fender instead of 37” with air ride plugged in. My front fender is at 35” factory. These measurements seem pretty much the same that I had on my factory setup Yukon Denali. So I’m hoping all the same things happen this time around.

 

[nick14226]

The Fabtech and ready lift are both solid budget lifts without sacrificing quality like you might on a Rough Country or similar. I only noticed very very minor rubbing on my Fabtech kit. I don’t remember it ever being an issue but remember seeing some scuff marks on my control arm if I can remember right. When I swapped from 20x9 0 offset to 20x10 -24 I noticed the scuff marks. But it def could’ve been from the 0 offset wheels bc the scuffs never got worse after the new wheels. But i never heard or noticed anything ever while driving. And now that I think about it....it may have even happened in a slanted elevated parking garage I lived in on my weekends in San Antonio. With ALL the mileage I put on it i never has any issues with the CV boots, ball joints, or rods. My 16 Yukon Denali had almost 240k miles on in it when I got rid of it. When I had the Fox 2.0 installed at about 215k miles I had the install shop go ahead and replace the ball joints ($48 apiece) since they were gonna be in there working around it. Figured since I had 75k+ miles on them might as well change them since so many guys reported failures at much lower mileage usage.


The 3” rear spring spacer definitely puts the rear axle in a bind, but nothing significantly noticeable. I would’ve never noticed but my first install was a nightmare in the Fabtech and the install place left something on my transmission disconnected that was clicking when I went over dips in the road. Some spot in Dallas was troubleshooting the install and mentioned it could be the rear end axle being in a bind and then i became aware of the slight shift. We later found that wasn’t the cause of the clicking noise and I ever added a pan hard bar to adjust the rear end. The BDS 4” kit included that adjustable pan hard but like you said it was overkill for what I wanted. I know with the 2” or less rear coil spring spacer the axle would look even better and I would say that it wouldn’t bother 99% of people. I’m it sure but I’ve seen people say with the 2” or less you don’t even have to add the supplied shock extensions and hardware in the Fabtech kit. But I’m not certain. I was even considering buying an extended rear shock for my rears but the Fabtech rep once again assured me that my ride quality would be no different if I did that vs. keeping factory shocks and using the hardware in the Fabtech box. I’m going to see if I lose rear height by swapping air ride shocks to Monroe. I already bypassed the air ride now before the install and my rear sits at 36.5” now to the fender instead of 37” with air ride plugged in. My front fender is at 35” factory. These measurements seem pretty much the same that I had on my factory setup Yukon Denali. So I’m hoping all the same things happen this time around.

Thanks so much for the additional info. If I pull the trigger I'm thinking the fabtech 3" in the rear and the additional 1-1/2" lower strut spacer in the front with the fabtech. As long as the UCA has enough travel because I would notice if it were bottoming out on the droop/bump stop. Buffalo, NY roads are a good test of suspension travel with dips and pot holes. Already running 20x10 -24, seems this setup will get me into 33x12.5's.

Unfortunately I'm in the 1% who notices stuff like that, haha. My front passenger side tire actually sticks out 1/4" further than my front driver side tire and I noticed that and it bugs me. Doesn't sound like much but it became noticeable with 0 and negative offset wheels. Front to rear track width is the same, and alignments are coming out good, so I'm almost thinking it's a body placement on the frame alignment issue. So if my rear axle shifted a bit to the passenger side, 1/4" - 1/2", it would almost line things up with the front. But if springs and shocks move out of vertical and that effects ride and longevity I'd likely want to fix it anyway with the adjustable panhard bar.

I thought there may be a slight advantage to the Readylift over the Fabtech because their listing stated no cutting needed (so figured they did something different so the front diff didn't need the cooling fin trimmed). But reading through the instructions for the readylift they state it may need to be trimmed, so if that advantage goes away doesn't seem the readylift is worth the extra money over the fabtech.

Just for reference, and this isn't apples to apples since I have standard shocks and not an XL length Yukon, but my 2017 SLE fenders measure out at 39" front and 39-1/8" rear with the 2.5/1 suspensionmaxx level and 285/55R20 KO2's. Seems a bit higher than most with this level and tire configuration.

 

[Nokturnal]

Now I wait for the Fabtech Kit to ship in a month or so....

gives me time to black out those center caps that were supposed to be black but it’s a black chrome. Gonna drop it off at the body shop for the grill install and debadging and buffing out all the imperfections and add ceramic.

 

[nick14226]

Now I wait for the Fabtech Kit to ship in a month or so....

gives me time to black out those center caps that were supposed to be black but it’s a black chrome. Gonna drop it off at the body shop for the grill install and debadging and buffing out all the imperfections and add ceramic.

View attachment 266432

Ahh, is the fabtech lift on back order?

So final verdict you’re doing the fabtech 3” front, 3” back, plus 1” lower spacer in the front and the Monroe’s?

I already have the 1.5 lower spacer from the adjustable suspensionmaxx front setup, so figure I’d use that if going forward with the fabtech. Mine is just about perfect to my eye at 2.5/1, so figure with fabtech and lower 1.5 I’d end up at 4.5/3 so same difference front to back.

 

[Nokturnal]

Ahh, is the fabtech lift on back order?

So final verdict you’re doing the fabtech 3” front, 3” back, plus 1” lower spacer in the front and the Monroe’s?

I already have the 1.5 lower spacer from the adjustable suspensionmaxx front setup, so figure I’d use that if going forward with the fabtech. Mine is just about perfect to my eye at 2.5/1, so figure with fabtech and lower 1.5 I’d end up at 4.5/3 so same difference front to back.

Yeah BDS 4-6 months backorder and Fabtech right before Christmas just went 3-4 weeks backorder. That’s what I get for taking my sweet time lol.

I’m gonna go 3” Fabtech with the 1” front lower strut and 2” rear coil spring spacer. Also upgrading to Monroe’s all the way around so I’ll see how that plays with my height but I’ll post measurements as soon as I install. The forged wheels and 295/70/18 nonLT are LIGHT! Pretty pumped I may not have to add much power to my 5.3 after all.

 

[Cadi_Mike]

Now I wait for the Fabtech Kit to ship in a month or so....

gives me time to black out those center caps that were supposed to be black but it’s a black chrome. Gonna drop it off at the body shop for the grill install and debadging and buffing out all the imperfections and add ceramic.

View attachment 266432

Do you have a close up pic of the wheel tire setup? What setup did you go with? It looks great from the side