Intro and Request For Suspension Help (1 Viewer)

Joined
Aug 26, 2019
Messages
15
Location
Michigan
Hello Everyone!

My name is Mike and I’ve been lurking on Mud for about a year now. I’ve been meaning to sign up and introduce myself for a while but I’m just slow. I picked up my very first LC last December after a few months of searching. It’s a beautiful black 2010 that had one owner, insanely good maintenance records, and 118k miles. It was bone stock then. Now it has bigger K02s, a Prinsu rack with lights, satoshi style grill, and I finally just ordered the Tough Dog lift and TT UCAs after agonizing deliberations. I’ll do a build thread at some point! Before I get into my request for help I’d like to thank all of you, with my most sincere appreciation, for the incredible resource and community you’ve created here on Mud. I’ve learned so much from reading on here - thank you all!!!

Now on to my request for help. I’ve always loved how nicely the LC drove, right up until I hit a large 3-ball trailer hitch while going 75mph on the expressway. Both left tires hit it. The front tire got over it while the rear tire, a basically new K02, blew out a big hole in the sidewall. 8 other cars hit this thing and blew tires! Ever since then, the LC has driven like complete garbage and I haven’t been able to get to the bottom of it. I’ve read every post I could find about ride quality on here and I’ve also gotten some good tips from Slee and Jason at TT, but I thought it might help to get all your opinions too. I’ve taken it to three shops, including my dealer, but it’s not totally fixed. Together they all said nothing is bent and that it just needed an alignment and to have the tires rebalanced. Those two things helped, but the remaining issues are that the ride quality is very harsh over bumps, the vehicle seems to sway and lurch even at low speeds, The shocks make a squish noise occasionally that I never heard before, there’s an infrequent clunk from the front over certain bumps (I also never heard this before), and most terribly, it is very squirrelly/sketchy on poor pavement, fast or slow. I’ve had the back end swing out on 20mph washboard dirt roads and had terrifying swaying/side stepping on the expressway when hitting an extended stretch of patched pavement.

I think it’s quite possible that the shocks are bad, although I see no leaks and don’t notice a difference when I stand on the running boards and rock the vehicle. I’m also wondering if the KDSS system could be somehow screwed up. To that point, I’ve spent over a week trying to loosen my severely rusted valves and have only succeeded in completely stripping them both out. The next step is welding bolts into the hexes as a last resort. I’m also thinking I could have bushing issues from the impact but I can’t see any issues there.

Anyway, here’s my action plan and I’m hoping you all can weigh in on whether or not this seems like the right approach. I’m quite frustrated and also willing to spend $ because I plan to drive this vehicle for a long time, hopefully up to 300k+ miles
1. Break open KDSS and try reset procedure by lifting rear end then setting back down.
2. Replace shocks/springs. Tough Dog stuff is already on order!
3. Replace UCAs (also on order)
4. Replace LCAs, sway bar links, and all other bushings. I’m on the fence about this, but I’m leaning towards spending the extra ~$1k here anyway to have a complete overhaul of all ball joints and bushings for the next 150k miles.
5. If it still doesn’t drive well, re-pressurize KDSS

Did I miss anything???

There are also three specific things I’ve noticed while crawling under the LC lately that may or may not be contributing to my problem.

1. the left sway bar link looks kind of odd to me with the wonky rubber washer and almost looks like the bolt is bent. Does that look normal to you guys?
1566873138054.jpeg


2. Possible small leak from front left wheel hub?
1566873166146.jpeg

3. The rear control arm linkage that connects near the rear KDSS cylinder moves side to side when I push on it. That seems odd to me. I’m really curious if lateral movement (about 1/2” in each direction) is normal for this or if this is supposed to be completely solid
1566873351410.jpeg


If you’ve read this far, I appreciate it. Sorry for the sinfully long post! Here’s a picture of my LC for grins:
1566873924766.png


Thanks!!!!!!
Mike
 

bloc

SILVER Star
Joined
Sep 19, 2008
Messages
6,425
Location
Central Texas
The only thing worse than blown out shocks is blown out shocks on one side of a vehicle but not the other. This can lead to very unpredictable behavior when transferring load from one side to the other. It is entirely likely that your shocks were damaged from a hit hard enough to blow out a LT KO2. Possibly even KDSS but the sway bars act as springs that limit the amount of force applied to and as a result pressure within the system, so without obvious leaks I'd say that is probably OK.

The tire and alignment shops assure you nothing is bent but have they actually put the vehicle in the air with the wheels spinning to see if any axles or hubs are bent? If all they were doing was checking the wheel/tire they may not be catching this. If I had to do it in my driveway I'd alternate having the front and rear driveshaft removed and the other end of the vehicle in the air to check for wheel/tire straightness while actually mounted to the vehicle. Our trucks use a VERY robust front hub and rear semi-floating axle but everything has a limit.

No, your rear KDSS link should not move side to side, especially if you are saying you can move it by hand. It is a quite solid rubber bushing in there.. Mine isn't loose but I can see significant cracking when I flex the vehicle up so I ordered replacements but haven't installed them yet. The two bushings in that arm are 48849-60050 and 48849-60090.. unfortunately I didn't take notes on which is which. But, if one is bad the other probably isn't far behind.

Don't worry about the hub leak unless it's being caused by a loose bearing. These have unit bearings in front with extra seals. There isn't much you can do there.. just replace the bearing, hub and seals if it goes bad. If you end up with the front end in the air to check for rotating assembly straightness it would be a good time to CAREFULLY check the knuckle for signs of bearing failure with a mechanic's stethoscope. Personally I'd remove the wheel/tire for that part of the process.
 
Joined
Aug 26, 2019
Messages
15
Location
Michigan
The only thing worse than blown out shocks is blown out shocks on one side of a vehicle but not the other. This can lead to very unpredictable behavior when transferring load from one side to the other. It is entirely likely that your shocks were damaged from a hit hard enough to blow out a LT KO2. Possibly even KDSS but the sway bars act as springs that limit the amount of force applied to and as a result pressure within the system, so without obvious leaks I'd say that is probably OK.

The tire and alignment shops assure you nothing is bent but have they actually put the vehicle in the air with the wheels spinning to see if any axles or hubs are bent? If all they were doing was checking the wheel/tire they may not be catching this. If I had to do it in my driveway I'd alternate having the front and rear driveshaft removed and the other end of the vehicle in the air to check for wheel/tire straightness while actually mounted to the vehicle. Our trucks use a VERY robust front hub and rear semi-floating axle but everything has a limit.

No, your rear KDSS link should not move side to side, especially if you are saying you can move it by hand. It is a quite solid rubber bushing in there.. Mine isn't loose but I can see significant cracking when I flex the vehicle up so I ordered replacements but haven't installed them yet. The two bushings in that arm are 48849-60050 and 48849-60090.. unfortunately I didn't take notes on which is which. But, if one is bad the other probably isn't far behind.

Don't worry about the hub leak unless it's being caused by a loose bearing. These have unit bearings in front with extra seals. There isn't much you can do there.. just replace the bearing, hub and seals if it goes bad. If you end up with the front end in the air to check for rotating assembly straightness it would be a good time to CAREFULLY check the knuckle for signs of bearing failure with a mechanic's stethoscope. Personally I'd remove the wheel/tire for that part of the process.

Thank you for the thoughtful response. I'm excited to see what my new shocks and springs do to the ride quality. Two of the shops that reviewed the suspension are pretty decent local mechanics, but they're entirely unfamiliar with LCs - I don't think either had ever seen one. I will add those bushings to my replacement parts list along with guiding the shop that will do the work with your advice. Thanks again!!
 
Joined
Aug 26, 2019
Messages
15
Location
Michigan
So, was it the bad shocks that caused the bad ride? Just need an update. :D

hey sorry for never updating... I have several things on my list of “need to post on mud” that I just haven’t done yet!

I ended up doing everything on my list above and more in one shot at the end of 2019. The short story is that the vehicle now drives beautifully, but I don’t really know for sure what the culprit was... probably the shocks! I’ve put 30-40k more happy miles on it since. For more details, read on.

I had to entirely replace the KDSS valve (dealer had to do that) which was a saga in and of itself. I had tried every trick in the book to crack open the bolts but everything failed including drilling them out and using bolt extractors and welding bolts to them. Nightmare!
Once that was installed, I installed the TD adjustable kit, Trail Tailor UCAs, new factory LCAs, sway bar links, and almost all bushings. I had an issue with the internal frame welded nuts shearing off the frame when loosening one of the front sway bar bushings (pics below) which required me to CNC a steel bracket to fish into the frame to connect the two internal nuts together so I could re-tighten them both. PSA - be careful with those. The side that I loosened by hand was fine. The side that I tried to save time by using an impact wrench broke. If anyone ever does this, message me and I’ll at minimum send you a CAD file.

Experience getting the KDSS valve replaced:
  • Dealer had never done this before and had to order a special tool to pressurize the system. They also had a couple issues:
    • Both mounting bolts broke off in the frame and needed to be drilled out and the holes were re-tapped
    • Dealer ordered wrong fluid, then didn’t order enough of the right fluid fluid
  • Valve Cost: $868 valve from discountpartsmonster.com. Note - the part is updated with new bolts that eliminate the internal hex of the original design. Yay!
  • Install cost: $900
  • Quoted 9 hours of labor
  • The LC was in the shop for 5 days - the first two they were figuring it out, ordering stuff, and letting penetrating oil do its thing. Once they got the wrong fluid in I took my car back to try again later. The last 3 days (more like 2.5 really), they were replacing the hardware, setting up the new tool, pressurizing the system, and testing it out.

KDSS Pressurization Tool:
1612405256080.jpeg


Correct KDSS fluid if you ever need to inform your dealer:
1612404630948.jpeg


Sway Bar Bushing Fix Pics (front right)
1612404818118.jpeg

1612405071568.jpeg

1612405392873.png
 
Joined
Feb 1, 2021
Messages
4
Location
Philippines
Thank you for the update! I guess the new valves are the ones that need a Hex key / allen key to open right? I still have the old ones with two bolts.
 

bloc

SILVER Star
Joined
Sep 19, 2008
Messages
6,425
Location
Central Texas
Thank you for the update! I guess the new valves are the ones that need a Hex key / allen key to open right? I still have the old ones with two bolts.
The new bolts are an 8mm external hex bolt like a normal bolt head, vs the 5mm internal Allen older design. Having new parts that you can protect with grease or LPS3 is a huge advantage, but some people are noting the new design is actually worse about succumbing to corrosion than the old one. The heads simply rust away into a round knob vs having the internal part that can be cleaned and used, even if they never end up actually moving again.
 

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