Suspension upgrades for better handling. Advice, comments?

[RainyDayRunner]

Keep your tires, replace shocks and springs

I think you will see the biggest difference in replacing your shocks and springs. I have a 2004 and am about to do both because it feels a bit like a boat at high speeds. I'm doing Bilstein 5100 and Moog springs. New sway bars won't do a thing if your shocks and springs are shot.

Considering your uses, you might want to keep the tires you have. They actually get great reviews on wet roads. They are not a winter tire though, so if you want good snow performance, then do something different. It's all about the load rating. I believe your tire is the equivalent of a C rated tire (standard), and going to E rated would be overkill since you don't offroad much. C rated are not stiffer than E rated...it's the other way around. An AT tire with the same load rating as your current one would not increase the stiffness. https://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=LTX+M/S2

Given the age, I would definitely do the springs. As long as you are doing that, you might as well do new shocks since that will stiffen it up a bit and relatively cheap.

 

[52577]

What is the difference between the Bilstein 4600 and 5100?

Correct me if wrong but my understanding is the 4600 and 5100 have exactly the same damping rates. The only difference is the 5100 is longer to allow for lift. Is this correct? No lift in this 4R's future.

I was incorrect in my original post. Upon checking the receipt of my last Bilstein purchase, I didn't put 5100's on my last rig, it was 4600's. I've corrected my OP.

 

[Bumbo]

Pass on the 4600, the 5100 is good from 0-2" of lift. You can use them in a no lift application just fine. Its a nice firm shock and the road handling manner will improve from stock.

Regarding the tires and based on what I am reading in this thread... don't get something heavy like a KO2. I like the tire, but I have two sets and when I swap from my off-road set to my on-road set, you can feel the up-spring weight.

My road tires do handle a lot better. Ya, they don't look super cool and aggressive, but the Michelin LTX MS2 is one of the best road handling tires I have ever used.

You can feel the agility of a lighter tire when you contrast them side by side.
Not to mention the comfort, quiet, and rain traction would be substantially better.

You could also consider increasing the track of the truck just a little bit. Not to the point of getting some wide 1.25" spacers, but even 3/4" per side would get you more stability when turning at higher speeds. You could also consider different rims in an offset to accomplish the same thing.

 

[52577]

Pass on the 4600 ...

Curious why? I had them on my last SUV, stock height and they were awesome. No plans on lifting this 4R Thanks!

 

[Bumbo]

Curious why? I had them on my last SUV, stock height and they were awesome. No plans on lifting this 4R Thanks!

No reason other than there is no disadvantage to picking the 5100 instead.

5100 gives you the option for leveling, should you ever want to do that. If you did buy replacement springs at any time and found that it was a little higher, then you wouldn't have to worry.

I do remember reading a thread a while back about someone being able to feel the difference between a 4600 and 5100.

I read the 5100 may have a slightly stiffer valving because it the shock can accommodate a lift, and was valved to help with heavier tires which generally go hand in hand with lifted trucks. I don't think anyone had really confirmed it, so take it as hearsay.

If you look at the user base of the 5100, its huge, and review after review, you pretty much know what you are going to get.

 

[Bumbo]

I still think you should re-look at your approach to tires... You should get something more along the lines of the Michelin LTX MS2 or AT2 which is their most "aggressive" tire.

If you don't have any plans to off-road, I can't imagine buying a KO2 for road use only. Or any other heavy tire for that matter. I know the KO2 or similar looks cool, but buying a tire because of aesthetics is like buying speakers because they match your room decor.

Michelin makes an awesome tire... and it's not like you can't thrash on them. I've had more than 1 set before, i've taken them off-road, abused them, and they really do an amazing job. Just let out 10 pounds and run in in the mid 20s off-road and ur golden. Very comfortable ride haha.

These picts are all using the LTX MS2

That said... I felt guilty for trashing on my road tires... but its nice to know they can hold up to some light trail use if I ever had to venture out.

These days I am better stocked with the right shoes for the job. But I still have a set of LTX MS2 for my road trips.

 

[52577]

^ Thanks.

I called Bilstein to ask and what "Bumbo" said above is pretty much accurate.

Bilstein said the 5100's are tuned to handle a lift, and will have a sightly stiffer ride. The 4600's are tuned for stock height, and comfort.

As you said if plans are not to level or lift, Bilstein said the 4600 would be the choice.

I put 4600's on my last, 4X4 SUV. It had very stiff stock springs which I kept. The 4600's transformed the handling from a slush bucket to sport handeling and they were phenomenal, but ride was still too harsh on the stiff stock springs.

I found this user experience online, same tires and wheel size as mine ...

..."I also added the 4600s (yellow body) shocks. Truck rode like a Cadillac with Michelin LTX M/S tires in 16" ..."

https://www.thehulltruth.com/5686421-post2.html

For those interested, the part numbers for the 4600's 2WD 4Runner are:

Front 24-188401
Rear 24-186049

|

 

[Bumbo]

You mentioned that you kept some stiffer springs from your last SUV.

I think its worth mentioning that spring rates might be flavoring how you feel about a shock.

The springs job is the hold up the weight of the vehical, the shocks job is to control the weight.

If its handling like a sports car, I would attribute that to the springs being stiff, more so than the shocks and not letting the shock really influence the handling.

Based on what Bilstein said, I would pick a 4600 or 5100 based on what you want in valving.

I think a softer spring with a 5100 makes for a nice ride, the firmer valving gives you some of that anti-roll while the softer spring allows the shock to actually put in the work. Its a digressive shock so its going to start firm until you get into a higher speed compression.

4600 with the softer springs would probably give you a pretty plush ride, but you might loose some of that stiffness around turns. I just haven't used the shock myself so I can't comment.

 

[52577]

If its handling like a sports car, I would attribute that to the springs being stiff, more so than the shocks and not letting the shock really influence the handling.

Yeah, stiffer springs can help in that regard. Although with my previous SUV, when the stock shocks we're new, with the stock stiff springs, it cornered fair to poor. It handled amazing on the same stiff stock springs with the 4600's, leading me to believe the Bilstein's had a lot to do with it.

I distinctly remember during ownership thinking to myself that I had to get rid of those springs as they were too harsh and ride unenjoyable. I just never did.

This 4Runner will take wide corners at slow to moderate speed okay. Faster sharper there is lean, and S turns it behaves like that Monroe link I posted previously, indicative of worn shocks.

 

[52577]

Got a quote today from Toyota to replace the shocks with my supplied Bilstein's. $589 labor + $103 for a 4 wheel alignment. Front bushings are $84 each. Total would be $860. Before tax. Is this reasonable?

Where would I get the aftermarket bushings and how many would I need for each shock? It looks like there is a top and bottom bushing for each sock?