S13 Rack Conversion

[ferret]

If anyone has ever wondered about this swap I can now confirm that it is quite simple. I have used a power steering rack in mine simply because my car had manual steering and I wanted power steer. Bear in mind that you will also need to swap to S13 hubs, brakes and struts at the same time. By the way this was done on a right hand drive aus spec car.

To do the swap you will need the following:
Complete S13 steering rack including tie rod ends
LHS rubber rack mount
The lower section of the S13 steering column (below the rubber spacer)
I used the S13 power steering lines and pump in mine, again because they came with the front cut and were laying on the floor. S12 lines and pump may well fit, but I didn\'t have them here to compare.

I\'m going to assume at this point that you already have the front of the car off the ground and the tie rods off the struts.
First, the easy bit. Undo the bolt that holds the lower knuckle of the steering column onto the rack, from memory it\'s easier to get at this from underneath with the car up on stands, undo the 2 bolts on each side that hold the rack in place and it will now drop down off the crossmember. The steering column may not be very willing to part company with the rack so a bit of persuasion with a hammer and/or heat may be necessary.

Next the fun starts, you can reuse the rubber mount off the rhs of the rack, but will need to fit the S13 rubber to the lhs. The stock S12 bracket and bolts that hold the rack in place can all be reused here, basically reverse the procedure above and you will have the rack in place.
Grab your power steering lines off the floor and slip them up and roughly into place, you will probably need to bend tham a little bit to get a neat fit. Be carefull though as you can kink them fairly easily and then they are good for nothing.

Screw the fittings into the rack before you mount any of the brackets so that you can make sure that the lines are in the right spot. The S13 brackets that hold the lines in place will be nowhere near fitting at the moment, but they can be easily bent to shape. I had to drill a new hole in the rhs bracket, but just bent the other 2 to suit. Took about 10mins with a pair of pliers.
Mount the fuid resoviour on the lhs strut tower, or wherever else suits you, holes will need to be drilled if you are using the S13 part, it\'s close, but again won\'t quite fit. Hook up your hoses to this and the pump.

Before trying to fit the tie rods to your shiny new (or in my case very grubby and second hand) S13 hubs, you will need to shorten the steering arms slightly and cut a small amount more thread for the lock nuts. You can probably get away with not extending the thread, but the adjustment will be limited. You will only need to cut about 10mm off to get the right length, run a file over the end of the steering arms hen you are finnished cutting them to remove any burr that may be left. put the tie rods back on and they can now be roughly adjusted and fitted to the hubs.

The only thing left now is the steering column, this will require a bit of specialist work unless you happen to have a machine shop in your back yard. First you will need to remove the lower section of your S12 column, mine was particularly stubborn and required a lot of CRC, heat and a few hits with a big hammer before it came loose.Once removed you can now throw it away. Take the lower section of S13 steering column mentioned earlier ad if you measure it up, you will find that with the small 2 bolt flange cut off the top it is exactly the right length to mate your new steering rack with your existing column.

Take it to a machine shop and get them to cut off the flange and machine a spline on the end to match the existing one. Once this is done you can go home and enjoy your new steering (after filling it with fluid and bleeding it of course).

As you can see it\'s not the most complex of jobs, and with a bit of preparation could be completed in a day. I hope that this helps out anyone who has been thinking about the swap and like me couldn\'t get a decent answer as to wheather it was even possible, let alone difficult.

Regards,

Jaimie

[seishuku]

Couldn\'t you keep using the S12 hubs, if you use the S12 tierod/rod ends?

[ferret]

Yes, if you use the S12 tie rods and rod ends you should be able to use the S12 hubs. I don\'t really see the point of the swap then though, I did the conversion because my car had manual steering and I had all of the power steering parts from my front cut sitting in the shed. Just made more sense to me to use the stuff that I already had rather than buying more parts so that I could convert it to power steering.

[YankeeDrifter]

Could I then add a S13 quick-rack?  Do they make them for S13\'s?

[ferret]

Can\'t say that I\'ve ever heard of an S13 quick rack, but then there\'s a lot of things that I haven\'t heard. I believe that the ratio used in the S13 rack is slightly lower than the S12, I would recomend using the S13 speed sensitive pump if you can too.

[Fester]

That\'s some good work there Ferret.

I\'ve often wondered about a power steering swap from an S13 (S12 donor cars are pretty hard to find), but I\'ve never felt inclined to pull my car apart to find out if it would fit... I\'m not the most mechanically minded person; give me a PCB, a soldering iron, and a handful of SMD components and I\'m happy but spanners, meh, that\'s work :roll:

[SHEPPO3930]

good job, add some modified tierod ends for more lock and you will be able to get that massive opposite lock happening mid drift, or just in the carpark when u wanna do a tight park

i have always thought about power steering, but my S12\'s manual steering is light and i dont seem to need it, so i havent bothered. please let me know mow much better it is, as the S13\'s i have driven didnt feel too much different to the S12, only the wheel was lighter, maybe thats a good thing.

good write up, maybe a possible sticky or into the \"already answered\" section.

[Umai Naa]

nah, sticky\'s fine;)

i was gonna do the s13 rack conversion my self, then i was gonna find a s12 pwr/str rack, but i\'ve decided that pwr/str isn\'t necessary for my needs.

more stuff = more weight = more potentional problems = more $$

i\'ll probably pull the exisiting rack out and exchange it for a rebuilt one (minus the tie-rods).

[Joel07]

Man, I don\'t think I\'ve ever even seen a manual steering S12 here in the states, and from the way you guys talk, almost all of them are manual down under?  I\'m jealous...   ;-)

[Umai Naa]

our cars got power steering standard from late \'85-onwards i think.

[hillkill]

I just found out that the Us model hicas equiped 240sx has a shorter lock to lock ratio. Just a bit of hopefully usefull knowledge.

[gadget1382]

Please PIN or Stickey this write up!

[RB25sx - SLPR]

Had anyone tried converting the entire steering column to an S13?

-Dan

[Umai Naa]

No, because the mounts are somewhat different.

Besides, why would you want that shitty rubber damper into the equation?

[silverarrow27]

No, because the mounts are somewhat different.

Besides, why would you want that shitty rubber damper into the equation?

Actually there are metal dampers that are available now to get rid of the rubber.

[TE27Levin]

ITs ALL a direct swap. You just need to make the lines. I used the stock S12 inners and outers.

[bartc_j]

im going to sticky this as the info is great, any chance you have any pics with this swap,,,

[gadget1382]

Swap will be happening starting monday... along with a few other things.
Will get photos and hopefully an easy way of doing it.

[Umai Naa]

Actually there are metal dampers that are available now to get rid of the rubber.

No shit, Sherlock.

[gadget1382]

QUOTE(silverarrow27 @ Apr 14 2008, 03:10 PM)

Actually there are metal dampers that are available now to get rid of the rubber.

No shit, Sherlock.

Unfortunatly that does not help...

I'm trying to come up with a way that will "limit" the amount of customisation required, as the S12 and S13 splines are very different. Welding them together is one way, but if involved in an accident, will possibly leave you pulling the steering wheel out of your chest even with a 4 point harness.

Not to mention you will feel road vibrations directly and strain the flex joints more.

DW i'll document it too