Suggestions with bj74 owners. Lookin to do an soa lift with mine and just want some experienced owners to tell me what they think. want it to perform to its most extreme with lots of flex but also worried about floppin it on its side or rear. Also it's an automatic.
Greetings!
I've been wheeling my '88 BJ74 with S/O for 8 years now. I have a love/hate thing going on with it. I Love the extreme performance. with 1.5" fender trimming, it runs 40" Irok's on flat springs. I've done hard core trails like Rubicon and Black Hills. I've done long distance expeditions like Canol Road and Inuvik. With 4.88 gears and factory cable lockers, It's a kick ass rig. And with the boost turned up to 21 lbs, and some head work to polish and port match everything, it runs down the highway with ease.
What I don't like about the spring over is the leaf springs themselves. There is little choice as to height or spring frequency. You get what you get. You also have no control over roll angle, squat, anti-squat. You also have major pinion rotation problems which I've addressed with a 'Bam Bar'. On the road, the truck is pitchy, rolly, and squaty.... just like every S/O ever built.
Loewenbrau might pipe in with his experience. He's also SO on mild lift springs, but with 60 axles. While running 37's instead of 40's, his truck is the same height as mine. 37's are about the max tire size without fender trimming.
Mine is as low as I could get it...so low that my tie rod and drag links actually make contact with the frame in extreme flex conditions. And that's with 10" from axle to frame in the front, and 14" in the rear. And I want it LOWER still!
S/O is effective, cheap and reliable, that's true. But it's so... 1980's. Sure, we have neat bits now to clean up the build like high steer arms and anti-wrap ladder bars, But it's an engineering debacle. I would strongly suggest following the 'modern' trend in 4x4 construction and going with a coil-over multi-link. You can select height, spring frequency, roll-axis, and squat. It's all 'engineered' now to get great performance. A truck on 40" tires will always have a high CG and will never corner like a sports car... but it can be engineered with the same principals, and you end up with a very predictable, controllable, and enjoyable on-road performance, much like a sports car.
I have one more expedition this spring on this S/O, and after that, I will be rebuilding this truck with a proper linked suspension. If you REALLY still want a S/O this fall, maybe we can make a deal... I might be convinced to sell you my complete axles with suspension that you could just bolt right up to your truck. I will have a build thread somewhere once I start that suspension build.
