Haynes Roadster Steering Rack Part 2

I wasn’t at all happy with my steering.

Because this car is 4×4, the rack was pushed nearly 2″ further forward than on a standard Haynes Roadster / Locost. The steering arms were angled backwards about 5 degrees. It didn’t look good.

Haynes Roadster Steering Rack

Ideally, the steering arms should be in-line with the steering arms / tie rods on the up-rights. Eventually, I will make new uprights from billet, but that doesn’t help me too much.

The suspension geometry on this car is completely different to a standard Haynes Roadster. This meant the steering rack was mounted an inch or so higher than normal. This extra height if anything, made the situation worse.

I wasn’t happy and the more times I walked past the car, the closer I got to getting the disc cutter out.

When a fellow 4×4 Haynes Roadster builder (Hi Valdas) sent me a few helpful facebook messages regarding my suspension – I definitely had to start again. He was nice enough to send me good pictures too (see below).
Thanks Valdas 🙂 I hope you don’t mind me showing your car. It is looking really good by the way.

Valdas Front Suspension

Valdas is quite lucky in that his car is left hand drive. This means he can get the rack several inches closer to the front differential. As you can just see in the image above, his rack in fact touches the differential. I didn’t have this option of moving the rack backwards because the pinion box on my right hand drive rack would be in the way and routing the shaft back to the steering wheel would have been impossible.

The only option was to move the rack behind the centre line of the upright / wheel and get a rack that worked in the opposite direction. Pull needed to become push. Moving the rack backwards meant moving it lower down to fit into a tiny hole. In lowering the rack, the distance between the ball joints on the steering arms had to be less.

The plan was to go to a scrap-yard and measure up some racks then do a lot of sums and take it from there. – That didn’t happen.

One lunch, I thought I’d check ebay for ideas. The first page I looked at was for a 1991 Citroen ZX Manual Rack £4.99, no bids, finishing in 5 minutes. The ball joints looked a lot closer together than my Escort MKII rack. I couldn’t find any dimensions, so I crudely scaled up the image and guessed it was probably ‘in the ball park’. I couldn’t tell too accurately, as the steering rack boots / gaiters masked what I really wanted to see. I found one low resolution picture on Google images that suggested that it was a rear mounted rack – but I couldn’t be 100% sure. – I was the only bidder.

On its’ arrival, I found the rack to be spot on, millimetre perfect for my needs and indeed rear mounted. What are the odds of that?

Haynes Roadster Rear Mounted Rack
(Notice the rubber gaitor flopping in the middle – the rack is actually flat!)

The right hand hub / upright is now on the left and visa versa. The steering arms now point backwards. Unfortunately the Ackermann Geometry is all messed up as a result.
I’ll sort that later – possibly with custom uprights.

The tie rod ball joints on the Citroen steering rack were only 2mm wider apart than the bottom arm suspension mounts, meaning when the rack was raised enough for the rubber gaiter to just clear the chassis, the rack was the perfect width. The ball joints of the rack should lie on a imaginary line drawn between the top inner A-arm mounts. When checking things out, I placed a ruler as a guide and I actually said ‘No Way!’ – At that point I got out the disc cutter and junked the old set-up.

Ideally, the rack needs to move another 3mm further forward, to be exactly in-line with the end of the steering arms (front to rear of car). It is still much, much better than the 50mm off line, I had with a front rack.

Haynes Roadster / Locost Rear mounted rack
(It’s still not bolted down in the above shot and sits slightly too far back)

There are still a couple of minor issues.

I need to find some smaller diameter rubber gaiters for the rack. The Citroen ones are an inch wider in diameter than the Escort items. They are huge and floppy and as such they rub on the bottom side of the differential. It shouldn’t be too hard to cure this issue with some smaller gaiters. Smaller gaiters or boots, might even give me the room to get that 3mm I need back. My initially search for these shows the ’91- ’94 Subaru Legacy to be the closest.

Haynes Roadster - Rear Mounted Steering Rack Clearance

The rack in the above shot is still sitting on a lump of wood and is about 2-3cm too high, but you can see how close it comes to the bottom of the differential and to the chassis. The differential, in this photo, is tilted way too far forward. It actually ended up 2.5° from level. What is a problem, is the prop-shaft flange is now where the output of the water pump is. I have already had the pump casing modified once, but I think there is still room for more modifications. The front prop-shaft Universal Joint (UJ) is doing more work, but all in all, I wish I had gone this route originally.

Now that a new front cross-member is in place, the rack sits 4mm too low. Why? You ask… It is bolted down solidly at the moment and but I have thick rubber washers on the way for it to sit on. They are not the urethane mounts I had before, but they might (???) add some vibration absorption. If I spot some thicker ones at an autojumble (Beaulieu AutoJumble?), they will find a good home. I don’t want too much wobble in the rack; not just because of the differential but also because the steering shaft UJ will be fairly close to the top of the oil filter and with the engine shifting about there could be a clash. It’s all very tight!

I think I went the Escort MKII route because everyone else did. No thought went into it at all. I now realise the mistake I made.

Advantages

One unanticipated bonus was the removal process for the front differential. Before, it had to be separated from its aluminium framework (in situ) and wobbled around for minutes before it would finally come out. With the rack now underneath,  the differential and framework can be taken out the front, in one piece, in just a couple seconds. – With all my skin still attached.

The Citroen rack is wider than the Escort so I don’t need rack extensions anywhere near as long as normal. In fact they will look similar to a double ended bolt with a nut in the middle. Unless you knew what to look for, you wouldn’t spot them.

The steering shaft will end up much more direct with only 2 universal joints and not 5. With 5 joints you could feel a tiny little bit of play / distortion. Each section of the original set-up was suspended by Rose joints to stop the shaft from flexing and moving too much. With 2, I don’t think you’ll be able to detect a thing and the supporting rose-joints will not be required. I will however have to make a custom UJ on the lathe, as the output shaft of the Citroen rack is huge compared with the Escort.

One final advantage is the price. The second-hand rack I have, could well have 200,000 miles on it. You can replace just the steering arms / tie rods for £14 a side and the boots for another £11 but why bother when a complete re-manufactured rack is £42. Ok, it’s not a quick ratio rack, but I don’t plan on going racing. Having said that, I have no idea what ratio the Citroen rack is and really ought to get back out in that garage and measure it!

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