S130 Recirculating Ball to Rack and Pinion

[Gollum]

So I just completed this swap on my '81 280ZX a bit ago and finally got the little gremlins sorted out. I'm going to cover brief (my idea of brief, which isn't always as such compared to others) details on how to go about the swap and such to help the next person along.

 

 

First though, why?

 

Recirculating ball steering, powered or not, has been around a LONG time. One of the better benefits of this style steering system is that your steering shaft angles don't have to be as angled in the engine bay, keeping the steering system out of the way for putting an engine in. It's other big benefit is that the main unit can be used on a huge variety of cars with just changing cheap linkage lengths. You can see why OEM's used them so extensively in the past... It also has a side benefit in some ways in that it's slightly more disconnected, helping the driver to not feel bumps in the road as much. A nice feature for a benz.

 

Rack and pinion on the other hand is a naturally very connected system and engineers have to find ways to keep it disconnected in some ways. It's a bit more complicated to engineer, but yields a very direct feeling steering in a compact package. But a main drawback is that without using complicated linkages your steering shaft needs to go more towards the center of the engine bay, as the input for the unit is further down the engine bay, and needs space away from the main "frame rail" of the front end assembly as compared to the recirculating ball that can be bolted directly to the side of the engine bay.

 

My main reason was that #1. I had one handy from a chassis I cut up years ago. #2 was that the recirculating ball setup is HEAVY and not only that but more than 8" higher off the ground. Bad juju. Now that I've had them both in my hands as complete systems I can say for certain that the rack and pinion saves you 20+ pounds, plus puts it much closer to the ground.

 

(for the remainder of this post I will refer to recirculating ball as RB and rack and pinion as RP)

What You Need

 

The RB cars have a different cross member which needs to be swapped from a car with a RP setup. Otherwise there's no tabs to bolt the actual rack to. And since the lower control arms are such a PITA to remove from the cross member, you might as well take them too.

 

Power Steering Lines - They're different and thus you want the lines from the pump to the rear housing (where the shaft enters the rack)

 

The rack itself (duh?)

 

The tie rods (should come with the rack in most cases)

 

The two hydraulic lines that are part of the rack assembly.

 

Optional

 

The actually steering shaft is slightly shorter in the RB cars versus the RP cars. Why nissan did this I can't fathom, but I was shocked when all was done and my shaft wouldn't quite reach.... grrrr. I made do by making an adapter that I'll explain, which is easy, but if you can get the whole shaft from the steering wheel down for the same price, do it!

 

 

The process

 

 

1. Jack the car up. Support it on at least two stands up front, or all 4 corners if your on flat ground. I wasn't, so two up front worked just fine. Make sure to support the car behind the engine and not using the cross member in any way. You'll want some space around the cross member and also the oil pan.

 

2. Next you'll need to support the engine, if even lift it slightly. I used just a foot length of 1x4 wood across two scissor jacks. The wood makes sure to cushion the pan, and having two jacks keeps the engine from rolling and allows me to balance it a bit.

 

3. Unbolt the topside of the engine mounts. I also put in their place LONG bolts, longer than 6" I think, so that I didn't have to worry about getting the holes to line up again later, because that's a PAIN.

 

4. While you're on the top side of the engine bay unbolt the steering shaft coupler and I also removed the brake reservoir heat shield to make it easier to get back there.

 

5. Now you can get under the car. Remove wheels (should have been obvious) unbolt the outside of the control arms, unbolt the sway bar end links, unbolt the bottom side of the engine mounts, unbolt the idler arm (that's the steering link bolted to the passenger side of the engine bay), unbolt the actual steering box.

 

6. This can be done at any point between removing wheels and such, but you need to remove the tie rods. This can be a serious PITA. If you want to make it go quickly a tie rod separator works wonders, but even that can sometimes not be enough. Rip the rubber off and take a propane torch to it for a solid minute or more, then give it a good whack with a small sledge. Should come right off. This step took me an hour but then I gave up and used heat... took 10 minutes or less at that point.

 

7. Remove power steering lines. There's one that's threaded. I used a 24mm I think but it was too tight (or was it 22mm...) so it might have been SAE. Either way, I made it work. Even an adjustable crescent should do fine. The other one is just a simple hose clamp. Expect leakage, have a pan handy.

 

8. Now that everything is unbolted, and the engine is supported, you can start lowering the cross member. There's just the 4 main bolts, so get a jack under there to catch it, and unbolt away. I used a shorter breaker bar, didn't have to bust out my 3 footer, so they're shouldn't be BAD. If the cross member doesn't seem to be dropping when you get it unbolted and lower the jack it's caught on something. Give it some jiggle and figure it out. It'll drop.

 

9. Now that you've gotten everything out get everything prepped and make sure you've got it all, and it's ready. Check all the hydraulic lines. Mine leaked, and wouldn't have if I'd just checked them ahead of time. And trust me, it's MUCH easier to get to them when the rack is OUT of the car, than in. I semi-dropped the cross member twice in order to get the leaks sorted out.

 

10. So assuming you now have a rack and cross member assembly ready to go, put it on your jack and start raising it up. Make sure to keep the lower joint of the steering shaft up where it needs to go as you bring the cross member up. As you get it threaded over the studs get the nuts on there to hold it but leave it loose. Even though the cross member was the last thing I loosened, it was the last thing I tightened. I wanted to make sure everything had it's fair room of play and sat nicely before cinching it down.

 

11. So assemble all that you disassembled but with the new parts and voila! Now do your own alignment or go have an alignment done. I'm not going over much of the details here because it should be pretty darn obvious since you just removed half of this stuff.

 

The Steering Shaft Coupler

 

As I said before, this was a serious annoyance. The lower shaft was a good 3/4" or more short so I had to figure out a solution. I took the nuts left over from the old recirculating ball box from the bolts that went through the frame rails and found some longer bolts with the same thread pattern as the old bolts. I then used the nuts as a spacer so that when I tightened the nut down I wasn't putting undo stress on the system pulling it together, and that it was a nice solid connection. Once I did all this I then notice I could hardly use my turn signals because I'd literally PULLED the whole steering shaft towards the engine bay a good 1/4" still. So I unbolted it again added 3 washers on each bolt to add some thickness to the makeshift spacer.

 

Why not to do this: You'll see there's a round cup that goes around this coupler connection. That's there to prevent anything from getting lodged in there and locking your steering up. Last thing you want is for some debris to get up in there and render your steering wheel useless. You'll find plenty of vehicles that don't have ANY such device at all, so I'm not so paranoid that I was worried about doing what I did, but it certainly does defeat the purpose the OEM engineers put that cup there for.... So like I said, if you can get the upper steering shaft for free, you might as well. It'll add a good 30 minutes to the ordeal, but it will be worth it I think.

 

 

 

That's it!

 

You'll now be rewarded for MUCH better feeling steering, a lower center of gravity, and a few pounds less of fat. The total process probably took me 12 hours if you include the time tackling the leaks. If I were to do the whole thing over again in one shot, I could handle it in about 5 hours or less. That said, I recommend to take an entire Saturday, because you just never know what complications you'll run into. Or if you're the real "while I'm at it" you'll find yourself scrubbing things clean while you're in there. Always over-estimate your time and keep your calendar happy.

 

All in all, I'm very happy with the results and have decided if I ever owned another 280ZX with a RB setup, that I'm definitely converting it. And now I can say I own probably one of the VERY few pre-'82 slick tops with a power rack and pinion steering system!

[Josh280z]

Dude, this is an awesome write up... While I don't have an RB setup this is useful with the L28 as well. Thanks for the contribution.

[ArchetypeDatsun]

Heck yeah thanks for the write up I also have a 81 280zx with an L28ET swap and that damn box gets in the way of the turbo and had to cut a piece off to fit propertly. The good thing is I got another 81 280zx but it's the Turbo model so it has the rack & pinion I believe they were manual R&P? You don't got any pictures of the process?

[Gollum]

Any of the manual racks will be RP, but the power RP units didn't start until the major revamp in '82. In '82 is where they also switched over to blade fuses, made headlight washers optional, etc. '81 was a weird in between because they changed the seats and some other things that carried over, but '81 shares a lot more in common with the earlier '79 car than it does the last '83 that rolled off the lot.

 

Sorry, no pictures of the process, but I still have all of the carnage in my garage so I'll snap some pics before it goes in the dumpster. It's hard to take time to clean up and take pictures during the process when you're all greasy.

[ArchetypeDatsun]

with this write up it should be pretty easy to change on mine.

[FricFrac]

+1 Good write up - pics would be nice if anyone does this swap in the future