King 2.5 vs 3.0 Bypass

Hey guys and gals,

Wanted to post a quick thread here to get some input from those of you that have the above set ups.

I am still trying to figure out what I want to do in the rear of the truck. I know I will be going with the u748 Deaver pack. The shocks are where i get stuck. I have had 2.5’s in the past on my Tacoma and know they work well. I have been strongly considering the 3.0 bypass in the rear to give the extra comp/rebound adjustments. Has anyone here had both of these shocks that can give me some real world advice.

Purpose of the truck is to provide a comfortable off road ride. Still would like to get up to speed on the dirt roads-desert flats that we have out west here. Not looking to mash my truck down Barstow if that helps give some idea of what I’ll be taking on.

We (wife, daughter, myself and our dog) will be doing some over and style trips this year and into the future so I just want to get the best quality ride possible while still keeping price point in mind.

 

So the biggest difference with the 2.5 vs 3.0 is going to be two major factors:

Oil capacity:
2.5 has approx 500cc of oil
3.0 has approx 750cc of oil

Shaft diameter:
2.5 runs a 3/4" shock shaft
3.0 runs a 7/8" shock shaft.

as far as tuneability etc, these both will offer similar abilities.. but what does this all mean for you

A 3.0 will provide greater shock shaft strength and the higher oil capacity means greater cooling capability.
Why? heat is the enemy with shocks, the hotter the oil becomes the viscosity changes, it becomes thinner, shortening the life of the oil as well as the flow characteristics.

However, does this mean you need 3.0's Answer: absolutely not
Why? because while our trucks are heavy and "extreme offroading" can easily build heat in 2.5's but not excessive to the point where 3.0's are "required".

I will use @osidepunker as a prime example. He runs a 2.5 fox 16" triple bypass in the rear of his truck and would most likely be one of the heaviest and fastest tundras I've seen in person. And even after many miles of hard and fast driving, his shocks are only mildly too hot to touch. 180-240 degrees.

Ideally, anything below 350-400 degrees is acceptable for max shock oil temps. (see race trucks)

So the bottom line is, do you need 3.0's, No. Will 2.5's work great, absolutely. If you want the added benefit of 3.0's then spend the extra $$

If you are looking to save a few bucks and still have an extremely capable rig that can go fast and ride comfortably off road then buy the 2.5's.

All that being said any tuneable shock regardless of brand and size, tuning them is an absolute requirement to get the ride you are looking for, both 2.5's and 3.0's will have that tuneable feature.

And for a bonus piece of info. For mild offroading and more street driving, Id suggest getting coilovers with clickers and if you can. clickers on your bypasses make tuning changes from dirt to street much easier as well. Yes, extra coin but worth it in my opinion. Now for a dedicated offroad truck like mine, its totally not needed, as the truck is tuned specifically for a set condition offroad. I do not care about on road driving behavior or feel. (although its pretty Cadillac on road too LOL)

 

everything Bruce said is correct except this part:

That does not apply to Fox, the shaft size is the same until you get to the 3.5" size

Also, the type of shock oil you use plays a role. I use Fox Racing oil which it good for temps up to 450. Plus my seals are Viton which can handle higher heat than other types of seals.

 

sorry I should have clarified, he is correct, I was specifically speaking about kings on the shaft size, in ref to your fox 2.5's I was specifically mentioning how they are fine with the heat you produce in the shocks, which most will never reach that level of "spirited" offroad driving LOL

 

one last point of mention on the shock oil... the King shock oil is the same used in their 3.5-4.5 race shocks as the 2.5 and 3.0 OEM performance series shocks.. so no issues there.

 

Bruce!

Thank you for all of this input here. This is exactly what I needed to rear. Being a number spec guru by default, seeing these comparisons side by side makes it clear cut for my use. Although the 3.0 does give some added strength and oil capacity, the 2.5 is more than enough for my plans with this truck. I know the deavers will be a huge improvement and the kings will compliment that to bring the rear up to where I want it to be at.

@sdhq_offroad, I am heading out to Phoenix this Friday and was planning to stop by and pick the rears up. Do y’all have some 2.5 King’s with adjusters in stock?

 

Absolutely no problem. I totally get it, and yes the deavers and king combo will be very nice, I mean really any shock, fox, ads, icon or king with deavers will be a drastic improvement over stock.

That said let me know if @sdhq_offroad cant hook you up ill see if any of my contacts can get a set for ya.

 

3.0 will give you something like 40% more damping than a 2.5. a 2.5 is similar to dual 2.0 shocks and a 3.0 is similar to dual 2.5 shocks. So if you feel you need more shock go 3.0.
a 2.0 shock isn't enough for these heavy trucks unless it never leaves the pavement. a 2.5 is a good choice and a 3.0 gives you more shock should you need it. And bypass shocks allow more fine tuning. I am in the process of going 3.0 cause I feel like I need more shock.

 

Week too late. Just sold all the Tundra Kings I had on the shelf. I have it all on order but nothing walk in pick up ready.

 

Shoot!

I will still be stopping in to check out the shop. Who knows what else might jump on the cart...

 

Bruce, question for you. Current set up 2024 Tundra Full Icon suspension with 2.5 CDEV. Considering changing out my front coil overs to 3.0 CDEV. Reason being. Going fast and hard there is sometimes a lot of downward force on the front. I’m adding a full ADD front bumper and winch. My concern is if sometimes getting some lift on the front from fast driving the truck lands hard. I’m assuming 3.0’s would offer better cushioning in this regards ? Plus those Icon 3.0 CDEV’s have internal bump stop when compressed more than 40% that should help in bottom outs I’m thinking. Am I thinking correctly?? Of course I need a buyer for my 2.5 CDEV’s haha

 

Spring rate and preload also play a factor on how the shock rebounds. If you have a ton of preload and are out of the correct ride zone you'll definitely hear thunk when that spring extends fast at full droop. A 3.0 will be better for sure but compression and rebound will also be a factor on how it feels and performs.

 

Thank you

 

Also spec the spring for the future planned weight

 

Bruce is a busy guy, not sure you will get a reply. I will give you some food for thought, and obviously this is my opinion and should be taken as such. First does a 3.0 coilover fit?, because none of them actually fit the previous gen 2 - 2.5, they hit or rub something. At full bump the frame mounted bump stop handles the forces, Toyota addressed this on the 3rd gen by keeping those forces down low in the frame rails, this was an issue on the previous gen chassis. Transferring too much compression damping into shock tower is not desirable… A hydraulic bump stop replacing the frame mounted bump would be way better. Finally you would likely exceed the design limitations of the chassis to notice a difference with a 3.0, not a good thing.

 

Thank Vizsla, Yes Icon makes 3.0’s to fit. 3rd Gen Tundra I went with Upgrade from 2.5 CDEV to 3.0 CDEV and of course links, track bar, springs Rear hydraulic pump stops and Icons front foam BS . No hydraulics available for BS in front. I am quit happy with the set up. Check out my truck at IG @Mr.tundra2.0

 

Are you running the 3.0 with the 2.5 in the back? If so how are you liking that setup?

 

I’ll add, went from stock length King 2.5s to King 3.0s. Will never buy another set of 2.5s, the 3.0s are that much better.

 

Yes 3.0 shock body and 2.5 resi. Love the set up