2015 LR4 126,000 miles What Preventive Maintenance to do next?

[DylanM]

Transmission pan. filter and fluid.
If you can figure out how to remove and install the sleeve, then you can get deeper inside and you can also do the seals.

Transfer case and front and rear differentials.

There is a canister for the air suspension on the left hand side (US Drivers) accessible from the interior at the brake light.

Definitely agree on changing these fluids (especially if there is no record of them being done) - the drivetrain smoothness will be noticeable after.

As far as the air suspension filter, it is accessible as long as you don't have rear climate-control...if you do, it's near impossible to get to...

A couple other things to suggest:
- Check / clean 4 sunroof drains
- Check / replace main and aux batteries
- Clean MAF sensors
- Replace xenon headlight bulbs if original (they will have lost a lot of output by now if original)
- Flush brake fluid
- Service parking brake / replace shoes
- Check all ground wires for corrosion, especially the one in the front wheel arch

 

[ftillier]

I mistakenly listened to advice and had poly bushings installed when we purchased ours in 2017 to replace worn out OEM ones. The 'lifetime' aspect appealed to me, but the harshness over bumps got to me and I replaced them with lemforder ones when I had to do tie rods. Noticeable reduction in NVH, and with the fcpeuro lifetime warranty if the bushings go again I'll just be out some labor and an alignment. Wish I had stuck with the OEM ones from the start.

 

[txfromwi]

You can do lower control arms yourself, parts are relatively inexpensive, but it is the one project that always bonks me on the head.
But, yes, always an alignment afterwards.

 

[richord]

Due to the extra stiff sidewalls, I find LT spec's tires to be like running with wooden wheels. If there is jarring over the bumps, this is the first thing I would fix.

There seems to be a lot of misunderstanding on the different tire load types. Your vehicle is not spec's to use LT tires. For your reading pleasure: https://tiresize.com/pressure-calculator/

Thanks.

I used the site and the recommended tires were still "truck" tires.

That said, my vehicle originally came with 19" wheels. The previous owner had them changed for 20" wheels. The sidewalls are smaller on the 20 inch wheel tires. The other factor I need to look at, is what should the inflation be for the 20" tires. The door sticker for the `19" shows 37 for the front and 43 for the rear.

I tried driving a short distance with the tires deflated to 34 front and 40 rear with no perceived difference in the ride quality over bumps.

I suspect the poly bushings that were installed previously maybe the main cause of harshness. From what I've read the rear bushing in the OEM front Lower Control Arms contain a fluid.

 

[richord]

Yes on the lower control arms.
Mine all needed replacing at about 60K.
I have never had luck pressing bearings so no way I will try to press those bushings, I went with OEM entire control arm assemblies.

You should have done this when you did the crossover pipes, but you absolutely need to replace the SuperCharger coupling and change the oil.

Transmission pan. filter and fluid.
If you can figure out how to remove and install the sleeve, then you can get deeper inside and you can also do the seals.

Transfer case and front and rear differentials.

There is a canister for the air suspension on the left hand side (US Drivers) accessible from the interior at the brake light.
There is also a drying agent for air suspension compressor, although it may just be easier to replace the entire compressor.
There a plenty of little valves etc. at many locations for the air suspension, I would just wait until they fail, but since you are looking for ideas.

Flush brake fluid.

For tires, I use Michelin Cross Climate 2.
Like driving a magic carpet, absolutely love them.
Our off roading is not extreme so no special tires for that.

Thanks. I only replaced the rear crossover pipe, without touching the Super Charger. The front pipes had been replaced by the previous owner by the dealer at 95,000 miles in 2022.

I tried to access the canister for the air suspension, but my vehicle has some pipes that prevent getting to it. I've seen videos of others accessing the cannister, but their vehicles did not have the pipes in the way. I suspect because mine is the HSE Lux that those pipes are there. They block access to the cannister.

I will attack the control arm assemblies next. I don't like the harsh ride that I attribute to the poly bushings that were previously installed. I tried loosening the bolts to see if they were going to be a problem, but they are not, so disassembly should be fine. I watched your video, so I have a good sense on how to approach this. I will order the OEM arms as well.

 

[txfromwi]

Yes, the OEM rear bushings on the lower front control arms are fluid filled.
It's a oil like substance, I didn't really take the time to look at it, I just cleaned it up.
I show the oil dripping out in the video.

Those poly bushing folks are quire loud and insistent in their opinions, I wonder if they are actual users or sales people making fake posts.....

If you found that lower control arm video, then you can find my other attempts, I hope that they are all useful.
Note that in the 2016 video for crossovers, there is a section on the SC coupling and oil change.

For that rear canister, you can always cut that tubing, abandon the old canister in place and install a new canister in a new locations.
I'm not sure if there is actually a service interval on that, I just did it when I replaced the compressor as it seemed like a good idea.

Yes, I know that videos are very long and excessively detailed - I make them that way so that I can just watch them myself the next time I need to do the same work - I don't want to do all that research again...

 

[BBLR3]

I put poly bushings on mine around 20K miles ago. They are definitely a harsher ride, but I was going on my third set of front LCA bushings and quite frankly I was just done with paying parts and labor to do LCA swaps every 70K miles or so. At this point I dont even notice the ride anymore as I'm used to it. Totally your decision if you want to go back to OEM, its your vehicle.

There is a thread on here about doing bushings without pulling LCA's completely off the vehicle. Assuming you have the type of poly bushing that just uses the LCA metal to hold it in, the hard part is technically done. You just drop the LCA's, pop out the polys, and use a bushing press tool to install the replacements. Reassemble and get it aligned.

 

[ftillier]

The poly bushings also change the loads on the control arms, where impacts that used to be absorbed by the rubber now aren't. I remember seeing a picture of a failed control arm in a post here, where the metal around the bushing at the front of the LCAs gave out (@djkaosone was it you?) For how much we drive our LR4, 70k miles will take 10+ years, so an OK replacement interval for me.

 

[greiswig]

I had poly bushings on the front lower arms. I got out of the truck to check for damage to the rear bumper after an obstacle on Hell’s Revenge trail near Moab, and noticed a slice of tomato sitting on the ground nearby.

…turned out it was a piece of one of the new poly bushings. I went back to stock.

 

[itsaguything]

Ah, I missed the LT tire vs P tire. Yep - that won't help!!! The Conti and Tire Rack websites don't make this clear.

CrossContact LX20 Specifications

continentaltire.com

Tire Rack

Again, also what many miss... LT tires must ALWAYS be properly inflated or you risk ruining the sidewall... P tires can be suitably deflated to accommodate traction on different terrains. Head on out and drive an F350, one with P tires, and the other with LTs. You'll see the difference, immediately.