Front and Rear Control Arms & Polyurethane Bushings

[CMoore711]

I'm trying to provide as much information as I can as to my current vehicle, what information I have been able to find so far, and what I'm trying to find out so bare with me on the long detailed post here...

My '15 Yukon Denali XL 4WD is quickly approaching 110K miles and I'd like to go through the front and rear suspension and replace/upgrade the control arms and suspension bushings.

My '15 Yukon Denali XL 4WD does have front aluminum control arms.

My K2XX Yukon Denali XL 4WD is lowered but not by much.
About 1.5" Drop Front
About 2.75" Drop Rear
Belltech 2" Drop Spindles in the front
Norcal Rear 1-4.5 Rear Adjustable Drop Kit
Adjusted Rear Auto-Ride Rod Lengths
Rear Has Free Travel Mod w/ lower profile bump stops
DJM Rear Offset Sway bar End Links

Spending some time doing some research on the line there seem to be some "beefier" aftermarket control arm options; However, all the ones I have found for the front seem to be designed for lifted or leveled trucks, I have yet to find any for stock height or lowered trucks.

For the rear control arms there is the Spohn Option for the 07-13 that do fit the K2XX SUV models. I'm partial to using the Spohn Lower Rear Control Arms with polyurethane bushings. But I don't have any experience with the Del-Sphere pivot joints that are on the Upper Rear Control Arms and fear they might be overkill for day-to-day commuting or add too much NVH. I could be completely off with that though? Then there's the rear auto-ride links; Although I'm not too keen on having to weld the rear auto-ride link attachment to the Spohn Rear Upper Control Arms if this was the only upgrade option that made sense I would consider it.

Looking at front and rear control arm part #'s on Rockauto across the different generations there are some of the same part #'s.

2006-2020 Use the same Rear Upper and Lower Control Arm Part #'s

So I was leaning towards going with OEM Rear Control Arm replacements and installing these polyurethane bushings into them in lieu of the rubber ones.
7318 | Escalade | Rear Control Arm Bushing Replacement Kit (prothanesuspensionparts.com)

There are no consistencies across the generations (2006-2020) for any of the front control arms. But I am curious if anyone can confirm if there are consistencies for the bushings and mounting hardware? Wondering if these polyurethane control arm bushings designed for 2000-2006 GMC Yukon XL 4WD would work the K2XX 4WD front control arms?
7236 | Tahoe | Front Control Arm Bushing Replacement Kit (prothanesuspensionparts.com)

My questions are:

1. Are there any aftermarket front control arms with polyurethane bushings out there designed to work with stock height K2XX 4WD SUV's that came with stock aluminum front control arms?
1A. If so, do you have any experience/feedback with them and a link to the product?

2. Are there any aftermarket rear control arms with polyurethane bushings out there designed to work with stock height K2XX 4WD SUV's that already have provisions to accommodate the auto-ride link attachment?
2A. If so, do you have any experience/feedback with them and a link to the product?

3. If you have any experience with the Spohn Rear control arms with the Del-Sphere pivot joints on your SUV on the street for day-to-day commuting? Would like to hear your feedback and input on their affects on the ride quality and NVH.

4. Has anyone successfully installed any of the above linked polyurethane control arm bushing kits into OEM front and/or rear control arms for the K2XX SUV platform?
4A. If so, please share any experience/feedback.

If anyone is aware of any other front or rear control arm upgrade options please share.

Thanks in advance for any information, input, or feedback.

 

[CMoore711]

So... After doing a bit more research and consulting with my good installer friend. I have found and confirmed some additional information.

The Prothane Kit 7236: 7236 | Tahoe | Front Control Arm Bushing Replacement Kit (prothanesuspensionparts.com)

Will NOT work with the K2XX SUV platform. I didn't realize that the 2000-2006 GM Full Size SUV's had torsion bar front suspension set-ups. We do not have that on our '15-'20 models.

I lost hope for a bit and was about to give up on front control arm poly bushings, but kept searching and found that Prothane does offer a front control arm poly bushing kit for the 2007-2017 1500 GMC Sierra/Chevrolet Silverado.
7243 | Front Control Arm Bushing Kit | Silverado 2007-2014 (prothanesuspensionparts.com)

This kit is designed to work with OEM front control arms and on the link above they clear show and detail them being installed into OEM control arms that visually look idential to what's on the front of the K2XX GM SUVs. Furthermore, referencing Rockauto the front GM OEM aluminum control arms for the 2015-2017 GMC Sierra 1500 Denali are the same part # as the 2015 GMC Yukon XL Denali.

I also did find some aftermarket control arms that are designed specifically to correct ball joint alignment on lowered applications. They are listed for the 2014-2018 Chevy/GMC Platform.

IHC - 2014-2018 Chevy/GMC Adjustable Upper Control arms lowered application(ALUMINUM & STAMPED) | Deviate Dezigns (dv8dz9.com)

They seem like a decent looking tubular control arm, but they are designed for significant drop; lowered 6"- 9". They have threaded ends on the mounting points so you can dial in the length based on the amount of drop you have for correct ball joint angle. Seeing as they are designed for being lowered 6"-9" I figured they probably wouldn't apply to my 1.5" front drop...

So I have ordered the following parts:

GM OEM Aluminum Front Upper and Lower Control Arms
Prothane 7243 Front Control Arm Polyurethane Bushing Kit
GM OEM Inner and Outer Tie Rod Ends
Spohn 2007-2014 GM SUV Tubular Rear Adjustable Panhard Bar Polyurethane Bushings
Spohn 2007-2014 Boxed Rear Lower Control Arms Polyurethane Bushings
GM OEM Rear Upper Control Arms
*Prothane 7318 Rear Control Arm Polyurethane Bushing Kit

*From this kit I will only be using the polyurethane rear upper control arm bushings swapped into the GM OEM Rear Upper Control Arms. Prothane wouldn't break up the kit... I get it.
*I didn't want to mess with a solution for the rear auto-ride links.

A little concerned that the front OEM Control Arms don't have zerk fittings to service the poly bushings, but we will over lubricate the crap out of those front bushings before install.

Now just waiting on parts to show up and scheduling a weekend to get the work done.

 

[87carl]

Can you drill and tap a hole for a zerk?
And it will be awhile till you recieve parts from spohn I ordered from them 3 weeks ago and they keep delaying shipping out

 

[CMoore711]

That could be an option, but the OEM Aluminum control arms are forged. So imagine they’re pretty hard. I should look into that so I can service the front bushings in case they become noisy because that will drive me nuts.

Certainly don’t want to hear that you’ve been waiting 3 weeks on an order from Spohn. That’s discouraging.

I also ordered a Hotchkis 2292 Front & Rear swaybar kit. These were previously on back order but Summit Racing has 5 kits left in stock.

 

[CMoore711]

Parts have showed up and swapping in polyurethane bushings has taken place for the front control arms. Learned quite a bit through the process and thought I'd post an update to anyone else looking to do any control arm polyurethane bushing upgrades. This will be a bit long and detailed but hopefully helpful to others.

The Prothane Front Control Arm Bushing Kit #7236 comes with all bushings and sleeves to replace the OEM rubber bushings in both front upper and lower control arms and overall went well, but did end up making one adjustment.

First you burn out the OEM rubber bushings. In my case these were brand new and not worn because I purchased new OEM control arms anyway. This process went pretty smooth and was straight forward.

Next was to press in the new poly bushings; which they were the right size and pressed right in.

Next is when things got a little interesting. So the Prothane poly bushings are longer than the OEM rubber ones and so are the steel crush sleeves.

OEM on the left and Prothane bushing kit sleeve on the right:

Because the OEM bushing sleeves are shorter they rely on these "end cap" style washers (not sure if that terminology is correct but I'm rolling with it) that have a small "nipple" that protrudes into the ID of the OEM rubber bushing and completes the length of the sleeve. With these "end cap" style washers installed into the OEM rubber bushing sleeve the overall sleeve length of the OEM sleeve becomes the same length as the Prothane bushing sleeve.

"End Cap" washer for OEM bushing sleeve:

OEM bushing sleeve with end cap washers on the right vs. Prothane bushing sleeve on the left:

The Prothane#7236 front control arm bushing kit is designed to be installed WIHTOUT reusing the "end cap" style washers. Because with those washers added into the Prothane poly bushing sleeve the sleeve now becomes longer in length than stock, and is too long to fit back into the body mounts on the truck.

Here is also where an issue presented itself...

Without reusing the "end cap" washers look at how much slack there is between the OEM control arm mounting bolt hardware and the ID of the Prothane Poly bushing sleeve:

That's a lot of slack! To me that's too much slack for something that is used to adjust your front camber and caster. So I immediately reached out to Prothane technical support which were very helpful and responsive. But they're answer was basically: "This is how the front control arm bushing kit is designed to be installed. Once the control arm is installed and torqued down to factory specs the slack of the mounting bolt hardware through the bushing sleeve becomes a non-issue." To which I said: "I get that once it's torqued down horizontally it's not an issue, but it's a 14mm (.551") bolt in a .718" ID sleeve; That's over 1/8" gap. Is it supposed to be centered before torquing it down? If so, How would I make sure of that? If I push it up or down before I tighten in position the control arm is now 1/8"+ either higher or lower in position than the OEM upper control arm location." Prothane assured me that they get this call, question, concern, all of the time for a lot of their bushing kits and then once the customers install them they never hear back of any issues after installation. Assured me that their R&D department has designed these kits to be installed this way and they work.

I suppose I was ok with the answer, but still not ok with the gap. So started thinking of and looking for solutions...

Ended up sourcing a sleeve to put inside the sleeve. Perfect OD to fit inside the Prothane bushing sleeve and perfect 14mm ID to match the OEM control arm mounting bolt hardware.

Bought a stick of this and cut sleeves to the exact same length as the Prothane bushing sleeves:

For clarification this issue only presented itself with the front upper control arms, there is no bushing sleeve fitment issues with the Prothane poly bushings for the front lower control arms.

 

[CMoore711]

Now for the Prothane Rear Control Arm Bushing Kit #7318...

I had already purchased the Spohn 2007-2014 Boxed Rear Lower Control Arms w/ Polyurethane Bushings and so I purchased the PRothane 7318 really just for the bushings that would swap out for the OEM rear upper control arms.

This was the kit that was more sure of that would work with the rear OEM control arms because doing some research on front and rear control arm part #'s on Rockauto across the different model years there are some of the same part #'s.

2006-2020 Use the same Rear Upper and Lower Control Arm Part #'s. There are some variations between OEM, MOOG, and MEVOTECH but overall still consistencies and same part #'s listed as fitment for multiple years 2006-2020 Tahoe, Yukon, Escalade.

So the replacement OEM rear upper control arms I purchased were MEVOTECH CMS501172 Supreme listed under the "Daily Driver" category on Rockauto.

The poly bushings and sleeves in this kit did not fit the OEM rear control arms at all, flat out were not the right size. Of course this was not learned until after we burned out the rubber bushings of one of the rear upper control arms.

The ID of this opening is 42mm:

The OD of the smaller bushing set of the kit is 40mm and not large enough, it's the right length, but too small of diameter. Here it is resting in the opening:

The larger bushing set is bout 45/47mm OD and too large to attempt to press in.

So the Prothane #7318 Rear Control Arm Bushing kit was a bust.

Installation is happening very soon, hopefully this weekend actually. We will be installing the following parts this weekend:

GM OEM Aluminum Front Upper and Lower Control Arms
With Prothane 7243 Front Control Arm Polyurethane Bushings Installed
GM OEM Inner and Outer Tie Rod Ends
Spohn 2007-2014 GM SUV Tubular Rear Adjustable Panhard Bar Polyurethane Bushings
Spohn 2007-2014 Boxed Rear Lower Control Arms Polyurethane Bushings
GM OEM Rear Upper Control Arms
Arnott AS3066 Rear Shocks
Hotchkis #2292 Front and Rear Swaybar Kit

I'll follow up on how the install goes and impressions on the ride quality and improvement. My front ball joints are on their way out and already have some slack in them. Along with my rear control arms and reach shocks all have 111K miles on them. Looking forward to tightening up the front end a good bit and reducing body roll for a more planted feel on the road.

 

[exp500]

Nice work and great writeup!
Watching the continuation.

 

[oldchev]

Great write up with mostly exacting details. 5 stars for removing the (front) upper and lower bushings whereas most comment to just get new control arms which you did however could be applied to those (like me) wanting to use my original control arms and install new bushings.
I have a question; would you say that burning or drilling the rubber out of the bushing is all you need to do in order to press out the bushing shell? or, did you collapse or cut the outer bushing shell to remove. How easy or hard was it for you and did you use any specific tools?
Thanks for sharing your secrets.
My intentions are to rebuild my (2004 denali) control arms (260k mi) with MOOG replacement bushings. I am rebuilding the entire front end including hubs and a good used (f) differential too!
Last decision will be the half shafts, which is the only part unpurchased at this time.

 

[CMoore711]

Great write up with mostly exacting details. 5 stars for removing the (front) upper and lower bushings whereas most comment to just get new control arms which you did however could be applied to those (like me) wanting to use my original control arms and install new bushings.
I have a question; would you say that burning or drilling the rubber out of the bushing is all you need to do in order to press out the bushing shell? or, did you collapse or cut the outer bushing shell to remove. How easy or hard was it for you and did you use any specific tools?
Thanks for sharing your secrets.
My intentions are to rebuild my (2004 denali) control arms (260k mi) with MOOG replacement bushings. I am rebuilding the entire front end including hubs and a good used (f) differential too!
Last decision will be the half shafts, which is the only part unpurchased at this time.

Burning them out worked pretty easily, just any small torch that'll allow you to burn them out. As the bushing heats up "melts" it begins to shrink and sort of detach itself from the ID of the control arm bushing shell. Then just use some plyers and pull them out.

I will say whatever bushing kit you decide to purchase and go with make sure it's designed for your specific model and year. As you read in some of my earlier posts I own a 2015 GMC Yukon XL Denali (which there is no specific bushing kit offered for) and used a front bushing kit for 2007-2016 Silverado/Sierra. I thought I was on the right track since some of the front control arm part numbers are shared across the models. I felt the bushings fit ok after install, but there's just a slightest amount of slack. That small amount of slack has lead to a lot of noise from the front end when going over larger harsher bumps.

Now with about 10K miles on this set up it rides great on flat surfaces and at highway speed, and as I drove over smoother humps or transitions its fine. But roll over a sewer lid, or sharper change in road surface elevation and it's supper noisey, squeks and creeks. Far too much for the excessive grease lube to compensate for.

Expensive little lesson learned I guess, but oh well. Tried to do an OEM+ front control arm set up but didn't turn out as I had hoped mixing OEM parts and aftermarket bushing kits.

I'll be going back to stock OEM front upper and lower control arms. Unless an aftermarket control arm with polyurethane bushings already installed becomes available for a stock height or lowered GMC Yukon I'll be sticking with OEMs. All of the aftermarket control arms I found are for leveled or lifted truck applications and designed to correct/change the ball joint angle to accommodate the raised ride height. Which would not be applicable for stock height lowered truck applications.

 

[signguy62]

( "For the rear control arms there is the Spohn Option for the 07-13 that do fit the K2XX SUV models." )
Reviving an old thread...
So you are saying the Sponh boxed lower trailing arms with poly joints will fit the DJM trailing arm relocation brackets?
I have the DJM kit installed and I purchased the Spohn boxed arms. But they don't appear as though they'll fit. The Spohn poly bushings don't want to go into the DJM brackets.
Any guidance you can provide would be greatly appreciated.

Thanks!

 

[91RS]

You’ll probably have to spread them out to get the arm in.

 

[CMoore711]

@signguy62 I did not run the DJM trailing arm relocation brackets in my setup. Sorry I couldn’t be of much help with that…

I would think @91RS suggestion could work as both parts are designed for stock OEM mounts and hardware.

 

[fozzi58]

( "For the rear control arms there is the Spohn Option for the 07-13 that do fit the K2XX SUV models." )
Reviving an old thread...
So you are saying the Sponh boxed lower trailing arms with poly joints will fit the DJM trailing arm relocation brackets?
I have the DJM kit installed and I purchased the Spohn boxed arms. But they don't appear as though they'll fit. The Spohn poly bushings don't want to go into the DJM brackets.
Any guidance you can provide would be greatly appreciated.

Thanks!

I ordered the Spohn kit (GMSUV-07-RK1) and it fit perfectly. Everything fit - I had a suspension specialist do the install since he is used to working on cars set up for the track. You don't need the DJM kit for it to work. The delsphere's on the Spohn kit relieve any possible binding.

I'm on a 4" drop out back and its all adjustable. Rear end is ridiculously planted. The ride is a bit harsher than I had hoped but she stays put. I started doing AutoX with the Burb this year and even the instructors were impressed with the big girl's handling.

I just bought @CMoore711 front UCA/LCA that he started this thread with. I'm gonna try and improve upon his idea and see what I come up with.

Wish me luck.

 

[fozzi58]

Just wanted to provide an update to anyone that may be interested in going with the Mevotech A-Arms and the Prothane bushings.

@CMoore711 was at the 1 yard line - I just took it in for a goal.

After consulting with my suspension guy as well as my mechanic, they both suggested I get someone to machine the proper bushings/sleeves.

OD is 1.030"
ID is 14mm as stated in the above thread.

Took the sleeves and measurements to a machine shop and voila! I'm $260 lighter but I have what CMoore was going for. Here are the units and here are them pressed in. I did not take a measurement of length. I'm going by what was posted earlier about them being the perfect length. I have some more parts I need to line up for my suspension but I will post a pic once they are installed and do a review. I'm interested in seeing how they fit and if there is any noticeable noise that OP was talking about when he did the "sleeve in sleeve" solution. I am hoping my outcome is better.

Will keep you posted.

 

[CMoore711]

Those are some nice looking machined sleeves, hopefully this is the answer to keeping them quiet and mounted snug.

 

[fozzi58]

All Done!!!

Mevotechs with the polys are in, along with my newly machined sleeves. Everything is tight and noise free! No clanking and no squeaks. A noticeable improvement in handling and I saved about 12lbs per side vs the factory stamped steel units. I replaced the swaybar end links with DJM poly's and they were a lot shorter too which also tightened up the front. I am awaiting replacement bushings from Eibach for the front sway where it mounts to the frame. That's the last thing to do. I am super excited to take this thing to the track now.

Wilwood came through and replaced my rotors and pads at no charge with a softer compound brake pad so the brake chatter would go away. Looking for some lightweight 20s or 22s with a custom offset so the wheels get pushed out a little further, and that should finish up my prep for AutoX season. Lots of trial an error from @CMoore711 and myself but I think we got everything we need now for a full poly/handling setup for our trucks.

Last thing to do is find someone making Poly body bushings. DM me if you want a parts list of everything I have on my truck. Lot of great info in this thread as well.

 

[CMoore711]

This set-up looks great @fozzi58! Glad to see the bushing sleeves you had machined worked out better; Having all new sleeves machined vs. inserting a sleeve into a sleeve made all the difference I bet.

Really glad to see Wilwood came through for you on some new rotors and pads at no charge! That's huge.

I bet your burb feels so much more solid and planted now.

 

[fozzi58]

I haven't driven it hard yet cause I am waiting for those replacement bushing for the front sway, but yeah its a noticeable difference. There's a little bit more harshness in the suspension but I am OK with the "Corvette-ness" of the truck. Looking forward to pushing this thing around some fast corners!