Making a RUF/YJ kit, a few questions.

[Ruru19]

Hi,

So I now have a 1997 Samurai Soft top 1.3i, all original at the moment but as I have the body off to weld up alot of holes and tidy it all up a bit, I was looking into a RUF/YJ set up, I have already made one before but as it was a few years ago and I didn't keep any of the info :(, I was looking for a bit of help! (As your all pro's on here I thought it was the best place to ask :p )
Basic idea is a RUF keeping front axle in place, make it look as much as stock as I can (French MOT reasons.) And would like to do a YJ on the rear.
I would like to fit 235/75/15 tyres on, the arches will be flatened out a bit, so shouldn't be a problem will have 10cm flares on, and eventually offset rims. WIll be SUA.
Questions are;

Is the standard RUF seating the rear mounting point at 1.5" behind the original one going to keep the front axle in stock position? Any need for steering/driveshaft mods?
What size shackles go you guy's run on the RUF/YJ set up?
For the rear setting the front mounting point at 3" forwards will the rear axle be in stock position?
Same question on shackle lengths?
What are the biggest tyres I can get on with axles in stock position without hitting the firewall?

Thanks alot, once I gather all the info I'll do a build thread with pics and progress.

[Ruru19]

I would like to run standard shackles no missing links.

[ScottieJ]

SJ rear springs are 39" while fronts are 37". I'm moving the rear mount back 1" on my lwb and then I will adjust my shackle length to correct the pinion/caster angle back into spec. When set up correctly slightly longer shackles on RUF can help achieve a bit more flex and the correct steering geometry. You can also just mount ther spring in the stock hanger and make an extension to move the front shackle mount forwards.

IMO one of the main benefits of RUF is to move the axle forwards a bit, increasing firewall clearance. I'll be re drilling my spring perches and U bolt plates to move my axle forwards a bit on my lwb.

Not how it would normally be done but i've cut off the original mounts and then used some off the back of a swb chassis tomove them back 1"

I'm guessing that i'm going to need a shackle around 100m between bolt centres but again this might need to be adjusted to correct the shackle angle and steering gemoetry.

This is the bolt on adapter design that is commonly used, i've never tried this one myself but i'm sure it works fine when the shackle lengths used with it are tweaked to correct the shackle angle and geometry.

If used on the rear for the YJ swap you'll need a shackle that is roughly 5.5" between bolt centres at a guess. Also bent to compensate for the different bush widths between the chassis and spring.

Keeping the driveline angles correct and steering gemoetry is the most important part of the set up, you can get away with a bit more caster on the front but never less, Make sure you keep the rear tbox output flange and differential flange as parrellel as possible, preferable within 1*

[d_r_1989]

Im also looking at doing the same on Andyrews old turk. Am i right in thinking that if i go behind the original hole by an inch and lower by say an half an inch then the shackle needs to end up an inch further forwards and half inch down and stock geometry will be acheived?
Is it actually that much better?
Normally i run spoa, but with no z bar and correct castor, cant complain with them, its been a while since iv been spua.

[Ruru19]

Hi,
Thanks Scottie ! Great amount of info there =), so after reading alot and studying this evening, if I turn the original mounts on the front around 180°, will set the mounting points 27mm back and about 10mm down, this should be about the same as what you have achived, this putting the front axle about 1/2 inch forward from stock?. How do you go about checking the caster angle, if the driveline angle are correct this should be not far off right?
Last time I used the bolt on adapter on the narrow axle SJ410 all around and had a great outcome and no problems at all, but stupidly didn't note any of the mesurements down!
Standard steering on this RUF shouldn't need anything doing to it, but would the Half high Mercedes arme make it better?

[ScottieJ]

Yeah just measure the diff pinion flange angle before and after the swap....front should be around 10* (+/-1*ish) on flat ground.

Just keep stock steering arms, there's no need to change the steerign set up at all.

[Ruru19]

So drawn this up, think its right for the YJ rears on the Samurai. Can send PDF to anyone who would like it. Tried on both chassis and good on both. Will be making a DXF drawing this evening, with a little space between the bracket and the chassis to add a plate.

[Ruru19]

Hi all, what yj packs are you running at the rear SPUA 4 or 5? I've found some nice 4's 2nd hand. Thanks

[ScottieJ]

4 front and 5 rear.