[seanzook06]

I own an sj70 and I am looking to do a RUF in the future, also looking at changing my spring spacing to NT spacing, to give extra flex, wandering if it has been done before, how hard it would be to do, and if it is worth it

[Gwagensteve]

Yes, it's been done - I've done it on a few cars. Is it hard to do? I have no idea what your skill level is. Obviously, it requires careful measurement, fabrication and chassis welding so it's not to be undertaken lightly. Is it worth it? Yes, not as much for the improved flex as the reduced roll stiffness and increased tyre clearance.

It's fairly time consuming and ideally requires the U bolt saddle from a NT car along with the NT spring plate and U bolts for the driver's side. Pulling the spring inboard brings the inside U bolt right up to the diff centre, requiring the longer and wider U bolt

[seanzook06]

I have fabrication experience, mostly simple stuff, like rock sliders and winch Bar. Where would I source the NT ubolts, saddle and plate, would wreckers be a good place to look. Also what steps would I take to complete the job

[Gwagensteve]

I doubt you'll have much luck with a wrecker but a specialist like Suziworld in Melbourne might be able to help.

Steps in the process? cut the spring hanger off and weld it back on under the chassis, but it's a bear of a job to cut off and weld as it's all out of position and there isn't much room with the gearbox in the car.

Then it's a matter of cutting the spring pads off the axle and rewelding them to suit NT spacing (or make new ones) which need to be correctly aligned. It's also a good opportunity to add another 3˚ of caster to improve handling.

The issue when it's done as part of RUF is that it's hard to keep everything aligned as both the front shackle hangers and the rear spring hangers, along with the shock mounts and the bumpstops are all off the car so there's little to use as a reference.

[atari4x4]

Bogfrog will hold your hand whilst doing WT to NT spacing

viewtopic.php?f=14&t=5293

[seanzook06]

Don't have the money to do RUF at the moment, so alignment shouldn't be an issue because I will be doing NT spacing separately

[Brenno]

Atari, he put WT diffs under a NT car. The OP has a WT and wants to convert to NT spacing which, IMO, isn't worth the hassle.

[Gwagensteve]

I think it is, if you’re already committed to RUF

[seanzook06]

I am commited to RUF, but dont have the money to do that at the moment, is it better to do the NT spacing now, and do RUF down the track, or do both at once

[Zook_Fan]

RUF is pretty inexpensive, it's mostly just fabrication work, a pair of springs and shocks.

I'd be doing both at once otherwise you're cutting all your mounts off, moving them in then cutting half of them back off to move the hangers out.

[seanzook06]

Thanks for that, the only other questions I have are, is it good to do a 2inch lift at the same time (looking at running 33s with 2inch spring lift + virtual lift within the next few years), and how easy would it be to get it signed off by an engineer

[Gwagensteve]

What height you need to run the car at is a function of how much compression travel you need to do the driving you do. 2" of compression travel is generally plenty. Generally the cars I've been involved in RUF have ended up on three leaves on the passenger side and four leaves on the driver's side and the car sits about standard height. You can add spring lift - a 2" lift rear spring when used in the front will net about 4" of lift, but there's no good reason to do this, it doesn't change the tyre size you can run and just negates a lot of the benefits of RUF.

The modifying factor is if you need to run bumpstop spacing for tyre clearance or some other reason like tie rod/pitman arm interference or sump clearance, you may want a little more camber in the springs to restore acceptable compression travel.

Bumpstop spacing (and ride height choice) also changes the optimum position of the shackle hanger when doing RUF and shock mount position, so it's best to resolve virtual lift, tyre & wheel, shock and ride height all together.

An engineer will sign off a RUF so long as all the fabrication has been done to their satisfaction. They will sign off a virtual lift as the car predates 1996. You won't get 33's signed off, you'll be stuck on 215's legally unless you can convince the engineer to reference the 16" wheel and 6.00 16 tyre "commercial" sierras which can *just* get you to a 31" tyre.

It IS legal to build a car to run a bigger tyre and cert it on the smaller tyre, the car is still not legal once the larger tyres are fitted.

There is no provision for a 50mm tyre increase over what the car was engineered on - the car MUST continue to run the tyres that the engineer approved the car to run.

[seanzook06]

Thanks, that pretty much answers all my questions.