Help 2019 TRD Pro Tire Cupping

OK, so I have this 2019 TRD Pro that I bought new (and I am increasingly regretting it ... it's been one of the least reliable vehicles I have owned in 40 years of owning vehicles.)

The 4Runner is on its second set of tires - Falken Wildpeak, 25k miles, about 50% of tread left.

In the last several thousand miles, the car has started a howling/droning noise - I thought it might be the needle bearing or wheel bearings last week, but after a visit to the dealer and an independent mechanic earlier this week, those are fine.

However, both report all 4 tires have cupping. Cupping, based on my research, is a result of bad alignment, worn shocks, lack of rotation, unbalanced tires, chronic under/over inflation, or (according to the Bridgestone website) cheap tires.

I had the alignment done when I changed the tires and after 15k. Just to make sure, I blew $100 today getting the alignment done again - results below. Nothing that would lead to cupping.

The tires are balanced. I check the pressure monthly. I rotate them every 5,000 miles. I don't think Falken would be considered cheap given how popular they are with the offroad community.

So, as far as I can tell, signals point to the shocks being the problem. The dealer did a suspension inspection when they looked at the wheel bearings etc. They didn't call anything out. Could the shocks be toast after 60k miles already? They are supposed to be fancy Fox racing shocks.

What is the next step? Just drive on the darn droning tires and turn up the music? Is there an easy way to evaluate shocks for wear? I can't find anything on line other than to assume the worst.

I don't really want to do a bunch of suspension work in case that's not the problem. But I'm kind of at a loss. This is new territory for me. Wish I had my 1998 Tacoma back ... at this point I'm developing a bit of a hate-hate relationship with the 4Runner.

 

Based on everything you listed, I'm guessing worn shocks.

Just another thought... where I live there are extreme variations in temperature. I have to monitor tire pressure constantly.

 

Stand next to your car, grab the roof rack and try shaking the car side to side. If it continues to sway like a boat after you leave it, your shocks are gone.
Any mechanic will also let you know if the shocks are gone after putting it on a lift.

60,000 miles is early for OEM shocks to go.Mine lasted 160,000.

 

At 60k miles shocks could very possibly need a rebuild. Most aftermarket shocks aimed towards performance will last 30-50k miles

 

Which part of the tire is wearing? I had a truck that would wear the inside of the front tires. Alignments and shocks never fixed it. I had to rotate the tires every 3000 miles and replace them before I really needed to.

 

I just went and looked at the Fox page (here) and it calls for a rebuild at 50k, so I guess I'm 10k over. Unfortunately, you have to send them to Fox - they don't sell rebuild kits for the OEM shocks they make. I have no idea how that works - I can't not drive for a few weeks.

I should have done my research. If I had have known that, I would have never of bought this model.

It appears to be the inside and yeah I'm going to need to replace the tires to get away from the noise. But need to figure out what to do with the shocks first.

 

Put some Bilstein 5100 or 6112 on it and be done with it. If you DIY, it can be done for <$1000. Then sell the stupid Fox shocks as is, or rebuild them and sell them for a decent price.

 

Yeah, I came to the same realization when I was deciding on suspension upgrades for my SR5P. As much as I wanted something more high end aftermarket (with rebuild requirements), my 4Runner is a daily driver, my only vehicle and I don't have a lift. I settled for Eibach Pro Truck at least for now. Will probably end up with something like 6112s.

 

I have some cupping on mine and it was suggested to rotate the tires more often, but the tires do have probably 40k+ on them and they are a AT tire so they will get noisy over time.

IMO its just how it is with vehicles like this and the off road tires we put on. They seem to cup over time, like every Jeep i have ever been in.

Now my Dealer HT's are super quiet and never had an issue, but they are a highway tire.

IMO its the tire class and over/under pressure more likely.

 

Cupping is an indication of a problem, somewhere. Either with alignment, worn suspension, unbalanced tires, or even cheap ass tires. It also really matters to rotate the tires every 5000-8000 miles, and maybe even have them rebalanced every other rotation. Also checking the alignment and suspension at least annually for indications of wear could help stave off a cupping problem. The last thing is to check tire inflation on a monthly basis. So many people never give this a second thought, and it's so easy.

 

Are the springs going to matter - it has springs that are presumably designed for the Fox shocks? I can see this turning into something complex if I'm not careful. I've been happy w how the vehicle handled both on and off-road, FWIW.

 

That is a good question. I'm pretty sure Toyota farmed out the struts to Fox with certain specifications, but did Fox design the spring? My thoughts are unless you're dealing with an adjustable coil-over, you should be able to use the stock springs. Especially with the 5100 and 6112 because they have different perch heights which can be user selected. If that's not the case, you can purchase a set of OME coil springs for around $215 that will fit perfectly with either Bilstein strut.

 

^Fox supplied only the shock. Toyota sourced springs and mounts elsewhere. Important thing to know if a Pro owner wants to get the shocks rebuilt.

You aren't the first one to report short life with Falken Wildpeaks, just sayin'...

 

Something like this would seem to be pretty close to replacing the Fox at around half the price ... and I think the rear springs would be fine.

 

^That's basically the 5th gen TRD Pro suspension 8 years ago: https://www.4runners.com/threads/trd-pro-suspension.4658/

 

THIS IS THE WAY.

 

Hopefully the new shocks solve your problem.

I can't agree with anyone saying that it's just how these vehicles are, or the type of tires. I have AT's with over 50K miles, and MT's with over 30K, and no cupping that I've noticed. This is on a Bilstein 6112/5100 setup.

 

What size tires do you have and what PSI are you running? Every time I get my tires rotated, they over inflate them to 38+ PSI. Didn’t notice the first couple times because I didn’t think to check. Ended up cupping the tires in the middle by 1/32 - 2/32. The actual PSI they should be inflated to is 26 based on a chalk test I did when I first got them.

 

That’s the setup I had installed on my 23, I love it.

 

38 would be correct for 285/70/17 LT tires. Although, a lot of people will run lower pressure based on a chalk test. The installers probably just look at a chart and inflate them accordingly. SL tires can be run lower.

 

Any idea what fox charges to rebuild?

 

Stock - 265 70R 17 SL … and yes I’ve run into the same thing. It’s possible I missed it once.

Nice. What did you do for rear springs?

I’ll have to read up on this chalk test.

$175 per so $700 plus shipping.

:-/

 

Well at $700 it might be worth it.

Find some standard oem shocks on marketplace($100 or less) swap them, then swap them back after rebuild.

 

What a pain in the ass. Not worth it in my mind. Unless you're running flat out in the desert, over huge whoops, and do it on a regular basis, Fox shocks are a joke otherwise.

 

I don't have the space, tools, or knowledge to be swapping shocks. I just want to do it once and get something a bit more durable. Doing some reading the 6112/51650 should be good for ~80k miles, and I can probably sell the Fox shocks for a few hundred to defray the cost.

@94hokie ... did you change the rear springs or just use the stock springs? I'm fine with the current lift/rake ... for the off-roading I do, I hit the skid plates but never the front or rear.

 

Yes, I replaced the whole deal. New springs front and rear along with the shocks. I ended up going 2.7" in the front with 1.5" in the rear, still has some slight forward rake which is what I wanted so when weight is in the back it isn't inverted. Great ride all around, I've been very happy with it.

 

I don’t know how they compare to the TRD Pro Fox, and your use case and how you use your car matters as to which degree which shocks are best.

That said, the only actual value a TRD Pro has ever added over an ORP are the shocks, and for a massive premium. The premium must’ve not been as bad in 2019 I assume though as it is today. And it’s crazy to think that this premium buys you trouble and higher expenses.

I’ve been very happy with my 5160 rears 6112 front Bilstein with B8 normal load 1.5” springs in the rear and a 1.9” lift up front. Again, don’t know how they compare to the TRD Pro Fox, but these work for me beautifully off-road and on-road. And rides taller than a TRD Pro.

 

Except the pro Bilstein struts had a softer coil when they were installing them on the pro’s.

 

This is the setup I had on my 2014 and now have on my 2021 and couldn’t be happier.

 

Hmmm $6000 in shock/struts for cupping that is probably just the tires?

I will be wanting to get new shock/struts soon for my KDSS 4R but 6k seems a bit much. Always liked Bilstein, i'll have to read up on the different levels.