Lx570 Rear Suspension Rebuild [Guide] (1 Viewer)

[skrypj]

Maybe a dumb question but could you lift the body of the truck ever so slight to get more access to the top of the shocks?

 

[TLCLVR]

Maybe a dumb question but could you lift the body of the truck ever so slight to get more access to the top of the shocks?

You can lift the body, but it requires removing a bunch of panels inside the truck to loosen the anchor points. I accessed everything with the rear shocks from the spare tire well. It's tight and a PITA, but not worth trying to lift the body unless your doing a body lift anyway.

 

[TeCKis300]

Bringing this great thread back up to the top. For rigs approaching 200k, especially those with lifts, replacing the rear 5-links will do a lot to bringing back tight ride control and ride quality. I'm at 180k miles, mildly 1.5" sensor lift, but I do tow an 8k trailer and off-road regularly.

I was getting a small lurch when taking off from a stop aggressively, almost like excess slack in the driveline. I did enough inspection to rule that out and suspected the links and that's what it turned out to be. Worn and sagging bushings in the links. Particularly the rear upper trailing arms where the bonded upper bushings were completely torn through. I chalk this up to extended AHC travel mods (or any aftermarket suspension with lift and extended travel). The short arms put more torsion into the bushings as they have to twist probably twice as much compared to longer lower arms.

Don't get me wrong, bonded bushings are where it's at for long term durability and the best NVH. Spherical or other race type links stand no chance in reaching even half this mileage. Which is why I went back to a new set of OEM arms.

Probably not a bad idea when lifting a vehicle to reset all the bushings by un-torquing and re-torquing with weight on wheels. I only did this for the lower arms front and rear, and it is really the shorter upper arms f/r that could benefit more from this.

Lower control arms somewhat okay but the centers were displaced outwards

Rear upper arms in really bad shape and both completely torn through.

Panhard was still in great shape.

Interesting notes:
- Rear upper arms are assymetric in length with the passenger side about 6mm shorter.
- LC (upper 2) and LX (lower 2) rear uppers are different part numbers because the LX has AHC height brackets.

Full set of rear 5-links

Tools
- Long taper punch sets are clutch for jobs like this to center the link in the bracket - https://www.amazon.com/dp/B004QXT00
- Pry bar, ratchet straps, and jacking are all useful to line things up
- All links use 19mm bolt and 24mm nuts. This HF long handle metric combination wrench set was MADE for this job and a great deal at ~$25. The 24mm wrench is also the perfect angle/depth to work around the upper link and pesky fuel tank.

More DIY install notes
- When installing the rear upper links, put the frame side bolts in first before trying to get the axle side bolt into the bracket. Jack up the axle a bit on the side being worked and things tend to magically line up.
- Clearance against the passenger upper link can be tight. May want to undo the brake line brackets just for that little bit of extra room.
- Make sure to torque all links with wheels down and full weight on wheels. This keeps the bushings relaxed at ride height, reducing torsional stress when cycling the suspension, and helping them live their longest life.

 

[TeCKis300]

Also adding @Boston Mangler 's thread as another great reference

Check Your Bushings and Swaybar Links!!!

Hey All I covered this in my build thread, but figured would also make a separate post as well. During refresh of my suspension bits, I was baffled by how torn, worn, and toasted ALL of the bushings were. Replaced ALL with new OEM and it’s honestly a completely different truck. Night and Day...

forum.ih8mud.com

 

[NKP Garage]

Interesting to see that much wear on the rear uppers. Do you think that's just normal wear and tear, or are your angles putting extra stress on those?

 

[tbisaacs]

My lower links and panhard looked okay at 170k but uppers are trashed. Not sure why but the bushings seem to take more abuse.

Interesting to see that much wear on the rear uppers. Do you think that's just normal wear and tear, or are your angles putting extra stress on those?

 

[TeCKis300]

Interesting to see that much wear on the rear uppers. Do you think that's just normal wear and tear, or are your angles putting extra stress on those?

It's probably a little bit of all of it.

Breaking this down, several types of stress on bushings:

Radial loads
- Acceleration and deceleration type loads. Harder driving and/or hauling greater weight/towing are going to create these types of loads which bushings are well suited for. Hard braking will also transfer large loads lateral loads into the links.

Torsional loads
- These are probably majority of the wear on the bushings. Particularly to the upper link as it's the shortest. When the rear suspension travels up/down travel, the shorter link will need to torsionally twist by relatively more. The greatest angular deformation will be when the suspension reaches the extents of its travel
- Suspension lift changes the angular neutral point of the bushing. So any lift will create more nominal twist on the bushing. Very few of us have bothered to reset all the bushing, including myself as I only did the lower links.
- Combine the fact that aftermarket or modded suspension employ longer travel, means the angular deformation experienced will be greater. Basically twisting the bonded bushing until it tears. Resetting the bushings when lifting can probably help a lot here to prevent

Twisting loads
- Combined with torsional loads from long travel may create the largest stresses trying to tear the bushing.

Over time with enough stress, fracture will show in the bushings, from which tears will continue to progress.

Off-roaders that commonly use the extents of suspension travel will wear the bushings the fastest. I chalk my regular off-road use to why my bushings are torn. Then again, most all OEM vehicles utilizing bonded bushings will see major benefits from refreshing the bushings at this mileage.

Stock rigs used for commuting are going to see the longest bushing life and I'm curious what that looks like in extended miles.

 

[LittleRock80]

So just to be clear, when changing out the rear shocks only, only the rear globes need to be bled down?

Notes: Rear shock leaking (fluid dripping on garage floor). New globes/full bleed within last six months. Rides great.

 

[lx200inAR]

So just to be clear, when changing out the rear shocks only, only the rear globes need to be bled down?

Notes: Rear shock leaking (fluid dripping on garage floor). New globes/full bleed within last six months. Rides great.

Yes, the fronts are not connected to the rears. The rears aren't always connected but can be.