2.5” vs 4” lift

[mchoward48]

Right now, my 8 is on what I believe is an old 2.5” superlift and 32in tires. It rides real rough and I want to go to 33x10.5in tires. I really like the way the Jeep sits though. So, if I were to change out springs, would 4” be the way to go or 2.5”? I found some good deals on used bds 4in springs on CL.

 

[timo439]

I have the same set-up with 31's and had the same rough ride. I replaced the shocks with Bilsteins and the ride is night and day. I actually enjoy driving the jeep again. When I took off the original shocks they had lost all of their "bounce". In fact, they had been installed what I consider upside down (rod up) and collected water. 2 of 4 poured out rusty water. It might be worth swapping the shocks.

 

[mchoward48]

I have the same set-up with 31's and had the same rough ride. I replaced the shocks with Bilsteins and the ride is night and day. I actually enjoy driving the jeep again. When I took off the original shocks they had lost all of their "bounce". In fact, they had been installed what I consider upside down (rod up) and collected water. 2 of 4 poured out rusty water. It might be worth swapping the shocks.

Okay thanks, which shocks did you go with?

 

[timo439]

I went with these below. They arent a perfect fit (a bit long) but I dont expect to hit their limits. Worth talking the 4wd folks on the right size. The ride is awesome.

BIL-33-185606 Front 14.13"-22.58"
BIL-33-186542 Rear 15.11-24.35

 

[CJ7Pilot]

For reference, I'm using 2.5" lift OME YJ springs, with Rocky-Road spring hangers (adding about 1/4" lift), M.O.R.E. YJ shackles (about another 1/2" lift), and a Daystar 1" body lift.

This amounts to about 3-1/4" lift (which I expect will sag a little over time), with 33x10.5 tires.

I like the way it looks, and there seems to be plenty of clearance.



By the way, the ride quality of the OME springs far surpassed my expectations!

I would absolutely repeat this mod in the future.

 

[gr8dain]

I ran 33s with a 2.5 inch Rancho spring lift with 1 inch of body lift and had plenty of clearance. The springs sagged eventually (after about 3-4 years) and I just put 4 inch superlift springs on. Still using the rancho shocks. The ride is not as bad as I had expected. Maybe the shocks are helping it out. But I have always heard that the superlift springs were hard.

 

[rubclt]

BDS 2.5" lift with BDS Shackles and stock tires

 

[spankrjs]

BDS 2.5" lift with BDS Shackles and stock tires

How does the BDS ride?

 

[joshvt]

I am on BDS 2.5” with BFG 33’s. (Actually 32.5”). No complaints about the ride, but this is my first scrambler so no basis for comparison other than stock.

 

[rubclt]

How does the BDS ride?

Not sure what Lift we removed but the BDS is a big improvement.

 

[spankrjs]

Not sure what Lift we removed but the BDS is a big improvement.

I am running 1" Superlift springs on my green Scrambler, wish they were softer. I am staying with 30" tires, maybe 31", just not sure if i want to go with a 2.5" lift.

I guess I could get custom 0-1" lift springs made

I am assuming those are stock tires in your above photo?

 

[Gueon]

33x12.50's sitting on a 4" Pro-Comp lift and Pro-Comp shocks, hand to God, worst riding Jeep to ever roll down the road.

I plan on swapping to a BDS lift later this year.

 

[spankrjs]

I'm thinking maybe BDS YJ conversion with 2" BDS YJ springs, a bit shorter then the 2.5" springs, maybe better fit for 30"-31" tires. Need to see if I can get the spring rates from BDS and compare to stock.

 

[surfjeepzx]

BDS 4" with 33 x 10.5's. The shocks are what BDS supplied with the kit. Basically what you're looking to do. It rides nice... like a Jeep.

 

[spankrjs]

BDS "CJ to YJ" spring conversion kit
BDS 2" YJ lift springs
30x9.50x15 Tires

 

[designerRob]

Looks perfect

 

[spankrjs]

Looks perfect

Thanks

 

[OGRES]

So what is the big benefit to the YJ springs? My new to me 8 rides a lot tougher than my last one did and I am looking to upgrade. I will need the 4" to 4.5" to clear the tires I currently have.

 

[spankrjs]

So what is the big benefit to the YJ springs? My new to me 8 rides a lot tougher than my last one did and I am looking to upgrade. I will need the 4" to 4.5" to clear the tires I currently have.

A wider/longer spring will be smoother then a narrower/shorter spring, spring rates the same for both, supposedly.

The RE 4.5" lift uses the wider 2.5" all the way around. Stock CJ uses 2" wide front springs, 2.5" wide rear springs.

A stock CJ rear spring is the same length as a stock YJ front or rear spring. The YJ front spring is 1"longer then the stock CJ front spring.

So, when using a YJ length front spring, you have to move the shackle hangers forward 1".

Stock vs stock, the YJ's used much lower spring rates then the CJ. But, spring rates are not the only thing that dictates the ride, i.e. teflon pads between the springs, other stuff.

All in all, I am happy with both the RE 4.5" lifts I have on two Scramblers, they ride great. I did add a main leaf to the rear packs on the V8 Scrambler, it was a bit too squishy feeling at high speeds.

I am very happy with the BDS 2" YJ springs/conversion kit on my green Scrambler, it rides great, too.

I do not have direct experience, but a lot of people are very happy with the Old Man Emu YJ springs, too.


As for spring rates, I did some research. This is what I found for various springs. Some came from manufacturers, some off the internet, so grain of salt and all that.

Superlift 1" Springs Front = 285 (5 leafs)
Superlift 1" Springs Rear = 350 (5 leafs)

OME CS036R Springs = 188 (commonly used front and rear)

BDS 2" YJ Springs = 276 ( four leafs)

Stock YJ 87-90 Front = 128/203 (stock/optional) (four leaf)
Stock YJ 87-90 Rear = 170/237 (stock/optional) (five leaf)

Stock YJ 91-95 Front = 113 (four leaf) (that seems petty low, must be 4cylinder spring rate?)
Stock YJ 91-95 Rear = 170 (five leaf)

Stock CJ Front = 170/185 (I know there are more rates then this)
Stock CJ Rear = 230/250 (I know there are more rates then this)

Rubicon Express 4.5" Front = 210
Rubicon Express 4.5" Rear = 224


Like I said, take it with a grain of salt. I do know the BDS YJ 2" springs are 276, I spoke to tech support before buying them. I was concerned that it seemed high, would be stiff. In reality, they are not, they ride really smooth.

 

[CJ7Pilot]

I pieced together my own swap for OME YJ springs.

I'm super-happy with the results, and I'd say the biggest improvement is on the washboard gravel roads leading out to my duck club.

Honestly, on these roads, my Scrambler rides more smoothly than my 2016 2WD Silverado!

I've heard that these springs sag quite a bit after a couple of seasons of "serious" off-roading, but for my purposes, I expect they'll last a decade or more.

Have fun!