I was working with someone who had a kit car. It was a classic mercedes that required a Mustang manual steering rack.

I was fairly impressed with the price and availability for these. Apparently alot of companies are building kits that use this Ford Steering Rack. Who would have thought a 70’s Mustang II steering rack would still be so popular?

They can also use power racks, which are nice if the car is bigger or heavier. If the car is lightweight and small I recommend sticking with power, since the power steering pump sucks power from the engine. Either way its nice to have a good supply of new racks and not have to worry about returning a core.

I get alot of questions about Bushing. (Alot of questions.) Half of them involve what they are. They are literally in every part of the car. They are esentially a connector between two pieces of metal. Most have some sort of rubber for impact absorbption. This article has to do with the Steering Rack bushings.

The rack and pinion steering unit goes the width of the car and thus has to mount somewhere. Usually there are two to three mount point and all have a bushing. The steering rack bushing can be a rubber grommet in the mount or a just a piece of rubber that goes inside a strap mount. These should always be inspected when replacing a rack. Worn or damanged bushings will cause too much movement and ultimately damage the steering gear.

The rule of thumb is that if they are pressed in, meaning they are permanent and do not get removed then you are good. If they are inserts and removeable you should change them.

So I got a tip on a problem part, a Mercedes Benz ML320 Steering pump. Looks like all 1998-2005 ML pumps are failing at very high rate. I’ve heard complaints of noise, low assist, pressure problems. Looks like bad bearings in the pump. The same part fits all of the ML series, including ML320, ML430 and ML500.

The good news is that the price on these has come down a good bit. They used to be about $600. CarSteering.com (1-800-399-7845) has these at $385 Original Equipment or $285 for their brand. Good people there and the best warranty I have heard of.

The other good news is that the new ones are re-designed and fixing the problem. Much better bearing pack internally. Just make sure you do a flush on the system and get good clean fluid in there. Otherwise you could ruin the whole Mercedes Steering Rack which is a much bigger problem.

Working on a question today involving a slow leaking Mercedes steering rack. The leak was coming from one of the hard lines. The questions are; What are the hard lines and how do you fix it?

See the attached image of the steering rack. The hard lines come from the pinion housing to the body of the rack. To make power steering work, these lines move fluid to different parts of the rack to help with the assist. In a power steering system, the fluid both ‘pushes’ the rack to that direction and ‘pulls’ the rack back in. In order to move the rack back to center, you need to press from the outside, and thus the hard lines. The hard lines will bring fluid to the outside of the rack and enable that ‘pulling’ action.

Hard lines are different that steering hoses. Steering hoses come from the pump and are usually rubber with metal fittings. That hard lines are all metal and thus the ‘hard’ lines name.

The question now is how to fix the leak. You can try removing the hard line, replacing the O-ring that is under there and tightening down. Sometimes this will stop the leak, but if something is warped or damaged there, you will have to replace the whole steering rack. You cannot purchase the hard lines separately. They are considered part of the rack. Hoses can be purchased separately

So we got some questions about our recent discussion on steering assist. The questions was, why only to the right?

The answer is that it can be to either side, that just happened to be the the example we used. If you are getting no assist to just one direction, left or right, then it is the rack valve.

If you are getting no assist or too much assist to both directions, it could be the rack, but more likely it is the steering pump. The pump does not know which way you are going, so if it happens to both sides, usually the pump is to blame. Larger shops have a steering pump tester to measure the pressure, this will quickly tell what the problem is.

So you are driving along and the you make a right turn but the Porsche Steering rack (or any other car) seems to have no assist that direction. You turn to the left and it turns normally. A little bit scary as you wonder what is going on. Can this even be possible?

Not only is this possible, its more common than you think. Fluid enters the steering rack and goes into the valve. The valve actually has a left valve and a right valve depending on which way you want to go. It is actually more common for one of these to become clogged or fail rather than both. So you could lose steering to either the left or the right side. Neither side is more common.

The picture below shows the actual valve inside of a volkswagen steering rack. You would only see this if you took it apart. The picture shows the two different valves and as the valve rotates with the direction of the vehicle the assist changes. Pretty clever engineering, especially when you consider that steering valves were invented in the 1950’s.

If your vehicle does not steer to one way or another, you will need to replace the whole steering rack.

So I was asked recently what is the deal with an EVO on a Lexus Steering Rack. Do I need that? Can I buy one with out? What is Servotronic?

First off, what is a servotronic unit? A servotronic unit, often referred to as a EVO or variable assist steering module is a computer assisted steering rack. The rack is not electric, it is still powered by hydraulic pressure coming from the steering pump, but the amount of pressure or assist coming from that pump changes depending on the speed of the vehicle. Drive faster and you need less assist. Make a turn in a parking lot and you need lots of assist.

If a vehicle came from the factory with EVO or Servotronic such as the Lexus LS400 steering rack , then you need to put back on a steering rack with the EVO on it. Most late model high end vehicles, such as most Mercedes Steering Rack have these units built in. Since the EVO is tied to the computer of the vehicle, you cannot really add an variable assist setup on the rack.

One more thing to keep in mind. The servotronic unit can be removed from the rack, see below. So often you can buy a rack ’supplied without evo’ and you can swap yours over. Since the EVO’s are expensive, this could save you lots of money if you just have a leaking steering rack or something else not realted to the EVO.

I was working with someone who had a kit car. It was a classic mercedes that required a Mustang manual steering rack.

I was fairly impressed with the price and availability for these. Apparently alot of companies are building kits that use this Ford Steering Rack. Who would have thought a 70’s Mustang II steering rack would still be so popular?

They can also use power racks, which are nice if the car is bigger or heavier. If the car is lightweight and small I recommend sticking with power, since the power steering pump sucks power from the engine. Either way its nice to have a good supply of new racks and not have to worry about returing a core.