Quality ... the degree of excellence

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BMW Steering Rack FAQ's

Steering Rack Illustration

TIE RODS, inner and outer?
When you say tie rods, think of the more than one. Actually there is an inner and an outer which are linked together with a threaded rod or pipe. The inner tie rod is attached to the end of the rack shaft and is usually covered by a bellow or boot. The boot helps keep water and dirt from damaging the rack shaft and the inner tie joint. The outer joint is typically attached to the spindle (the spindle supports the wheel bearings, wheel, and brake system) and it also has a small boot covering it. The threaded rod in between the inner and outer tie rod is used to adjust the toe alignment of the car (toes in pigeons and or toes out for ducks).

TIE RODS, when do I need new ones?
If your car has over 80,000 miles on the odometer and you are replacing your rack it makes economic sense to replace the entire tie rod "assembly", that's inner and outer rods and boots. Since you have to remove the tie rod assembly from the rack shaft when you replace the rack, for the small difference in material cost you might as well replace the entire assembly and the boots as well. Imagine if you went through the process of :(a) removing the old rack, (b) putting your old tie rod assemblies and boots on the remanufactured rack, (c) re-installed the rack in your car, (d) did an alignment ....... and the following year your car is wondering all over the road because your old tie rods were near their life limit. It's smarter to do the job right and only once (get the long rack). AND, in many cases, depending upon your vehicles suspension design, you can't tell if the tie rods are good or bad until you remove them; referring to inner tie rods that are under "load" while on the vehicle.

What is a ZF rack?
ZF stands for the ZF Friedrichshafen AGcompany. With respect to steering racks and pumps, they are the original manufacturer of certain racks and pumps. However, many other companies remanufacture or repair ZF products and other brands. Griffiths Technical Inc. specializes in remanufacturing primarily ZF brand products. Griffiths is not associated with ZF.

What is a CORE and why do I have to pay a deposit?
All remanufactured products are sold on an "exchange" basis, meaning you are exchanging your rack or pump for a remanufactured one. A "core" refers to your old rack or pump. A core deposit is a deposit you pay until such time that you return a good core to us (in essence you are buying a remanufactured product and its core). The core deposit is refundable when you return your old rack or pump, however your core is subject to the suppliers acceptance criteria. For instance: a damaged core cannot be economically remanufactured therefore it has no value. Damage cores are not refundable. Damage cores are typically cores that have been in an accident or fire, they are bent, broken, have been disassembled or are missing parts. In most instances you will not have a problem getting your core deposit back if you: (i) know your rack or pump is not "damaged" and (ii) you are on the level with the supplier. Most core returns as most replacements are for leaks or normal wear.

Core returns must be of the same make and model, for example: if you are purchasing an E30 post 11/86 rack you should be returning the same model, or if you are purchasing an M3 rack you must return an M3 core.

The "quality" of the core is important to you and the remanufacturer. A high quality remanufactured product starts off as a good core. If you return a core that is damaged and the remanufacturer accepts it, you have to wonder about the quality of the product they are selling you.

What is the DIFFERENCE between: "refurbished, reconditioned, repaired, rebuilt, overhauled and remanufactured"
They are all different and that is where the difference in price is. Every company uses it's own terminology so it's best to ask "what does your processing entail, or what am I getting for my money":
Refurbished: could mean someone found a used part in a junk yard, quickly looked over the outside, clean it up a bit and put it in a box.
Reconditioned: could mean someone found a used part in a junk yard, quickly looked over the outside, clean it up a bit, spray painted it and put it in a box.
Repaired: fixed only what was obviously wrong.
Rebuilt: fixed what was obviously wrong and maybe what could go wrong later.
Overhauled: same as remanufactured but may or may not be near OEM standards.
Remanufactured: a complete disassembly of the product, a thorough cleaning and complete inspection & repair or replacement of damaged or critical components, proper reassembly (torque & technique) of the product, a pre test inspection, complete hydraulic test, final inspection and proper packaging for storage and shipment..... quality is the degree of excellence.

There is red or clear fluid under my car. Where is it coming from?
We'll, don't be afraid to touch it (just remember to wash your hands well later) or crawl under the car to see where it is coming from (a piece of cardboard helps keep the pants clean in such scenarios). If you decide to pop open the hood make sure the engine is off (you'd be surprised how often we forget safety issues). Motor oil, automatic transmission fluid (ATF), and brake fluid are all a little bit different. If the color is brownish to clear and you find yourself adding oil when the dip stick is low then it most likely is an engine oil leak. If the color is clear, the fluid seems thinner than (the viscosity) motor oil, and the fluid washes away easily with water or evaporates after a few days then it could be brake fluid, so check your brake reservoir. If the color is red to dark red and it feels almost like engine oil then it could be ATF (automatic transmission fluid). ATF is used in cars with automatic transmissions and ATF is also used for the power steering. So if you have an automatic trans. check the dip stick. If you are under the car check by the transmission for tranny leaks. Power steering leaks are more common from the rack. As the rack seals or other rack components fail the fluid bypasses the shaft seal and ends up in the rack boot or bellows. If you feel ambitious you can safely get the car up and pull back a rack boot. If there is fluid in there then you need a remanufactured rack. While you are investigating the rack you should inspect the hydraulic fittings attached to the rack (where the hose lines connect), check the hose lines and the power steering reservoir. The last culprit in the power steering system to check is the pump. Pump leaks are more common behind the pulley (a shaft seal) or between the pumps case halves. If you cannot locate the leak simply park your car over a large piece of cardboard in the evening and check it the next morning. The location of the drops on the cardboard with respect to the drip should give you an indication as to where to look.

My power steering rack's boots are full of fluid. Can't I just replace the boot?
Sorry. No. It won't work. The fluid leaked into the boot because the shaft seal or lower pinion seal failed. The boot is only designed to keep dust, dirt and water out of the rack. The pressure in the steering system can reach up to 110 bar ( one bar equals about 14.5 psi) or 1595 psi. Since the atmosphere around you and the rack is only about 14.7 psi and the pressure coming out of the rack is so much greater, replacing the boot will not solve the problem. It's only a matter of time before the fluid fills up the boot all the way and leaks out of the boot. The solution is to replace the rack and you might as well put on a fresh set of boots while you are at it.

The power steering pump is making an awful groan or grinding noise. What's the problem?
This could be caused by two problems. First, the pump could be low on fluid so its "cavitating" - when bubbles form in the fluid low pressure area and collapse in a higher pressure area of the pump, causing noise, damage and a loss of capacity. Cavitating is not good. If you continue to run the pump with this problem if will wear out very very quickly. Second, your pump is already worn out. A worn pump will not fix itself. Time to place the pump and check for any leaks in the system (such as the rack).

I saw this stuff in the auto parts store that "revitalizes and restores the seals". Will it work?
Doubtful. Very doubtful. If it worked you would have to assume that there would be no need for remanufactured
racks, pumps or new hoses. Remember, the high pressure rack or pump seals are designed to withstand high pressure, which can be up to 75 or 110 bar (1087 to 1595 psi). When a seal breaks or wears down we know of no "wonder fluid" that can mend or repair it. The same goes for rack shaft or pinion surfaces which are made of steel, we know of no fluid in a can that can remove the pits, re weld new steel and grind it back to its original size and finish. And, some of these "wonder fluids" may do more harm than good by swelling or changing the durometer (hardness) of rubber components in the system. We will say we have seen a fluid you dump in your radiator that will "temporarily" slow down or stop a low pressure leak (until you can sell the car).

My car is handling funny. Is it the rack?
Maybe not. It is very difficult to inspect, analyze or guess what the exact problem is over the phone or through email. The smartest thing to do is to bring your car to a professional who is familiar with that particular suspension. Most front end specialists can find common problems, and it's worth your time and small investment to get an expert opinion and "quote" (why worry and postulate the unknown). What you can do is ask yourself some questions: (a) how many miles are on the car, (b) when is the last time I had a front end alignment, (c) do the ball joints, inner and outer tie rods or shocks have over 100,000 miles on them, or (d) don't laugh, how's the tire pressure.

What kind of fluid should I use for my power steering system?
We could probably list all the types you could use but the smartest thing to do is look in your car owners manual. If you don't have one then look at the power steering reservoir or it's cap. If that fails try your local dealer's parts or service department. Some BMW's may "require" you use their proprietary fluid. In most cases you can use ATF "Dexron" Type II or III. If you choose Dexron you do not need synthetic and any brand will do just fine.

What is the difference between a "short" and a "long" rack?
A short rack is simply the rack and pinion assembly without inner or outer tie rods attached. A long rack has two interpretations in the industry: it could be a short rack with inner tie rods and boots attached, or it could include both the inner & outer tie rods and boots. The inner tie rods attach to the rack. The outer tie rods are connected to the inners by a thread rod or adjustment tube, with the outer connecting to the spindle.

When should I buy a short or a long rack?
The rule of thumb is: if your car has over 80,000 miles on it, you have no known history of the tie rods being replaced, and you are in need of replacing the rack, then you are smart to get a long rack. Why? Well it is a matter of economics. When you replace the "short" rack you have remove the inner tie rods from the old rack and attach them to the new, and in some cases you have remove the outer tie rods from the spindles. So if you are going through all this work it makes sense to do the job "right and once". Imagine if you only replaced the rack and not the tie rod assemblies, and 10k or 20k miles later you need to replace one or two. You'd have to find the time to do the work or make an appointment, pay or do more than half of the work that was done before, and get another alignment! When in doubt buy the long rack. Griffiths usually stocks both long and short racks.

Why and I seeing a wide range of prices for rebuilt racks?
Pricing is relative to what you are buying! Some rebuilders really to a good job, from "tip to tail" as they. With remanufactured or rebuilt products there is a great range of price. Think of it this way, if you were to buy a "new part in the box" which is made by only one company, all you would have to do is shop around for the best price because no matter where you buy it you will always get the same part and same quality. However with rebuilt products it all depends upon who rebuilt or remanufactured it, how much labor and materials they invested, and how much pride they have in the work they do. It is true "you get what you pay for", so ask questions of your supplier. My favorite analogy comes from a good friend who said "There are two ways to buys oats. Before the horse eats them or after the horse eats um."

Why can't I just buy "seals" and fix it myself ?
If you like to "tinker", know how to "tinker", got the time to tinker and you have all the right "tinkering" tools and equipment, well then maybe you can attempt to rebuild one rack successfully. However it is not that simple if you want to do the job right and do it only once. Let the experienced people handle the "remanufacturing" while you enjoy driving your car.

How hard is it to replace the rack?
It is done often by car owners and takes about a half a day. It is a lot easier than replacing your kitchen cabinets but a bit more time consuming than the alternator. We would say somewhat close to time and effort to do your shocks. Here is the common scenario: You need to get the car in the air safely, this means either on goods jack stands (don't try rely on the car's jack) or on a lift. You disconnect the hydraulic lines at the rack. Loosen the bolt in the universal collar attaching the steering shaft to the rack's pinion (input shaft). Remove two bolts (typical) holding the rack to the cross member. Disconnect the tie rods either at the spindle or between the inner and outers. Sometimes slightly jack up the motor on one side (early model cars). Pull the rack out of the car. Remove the rack boots (just cut the old ones off because you are going to use new ones later). Turn the racks pinion so the rack shaft's end with the gear is all the way out of the housing. Bend back the inner tie rod clips (large washer tabs). Place the rack (gear section) in a bench vise that has soft jaws (brass or aluminum to prevent the rack shaft from damage). NOTE: we are securing the rack shaft because we do not want it to twist against the pinion and damage the inner bearings or gear set. Counter clockwise turn the inner tie rods to remove them. Slip the new boots over the tie rods. Attach a new inner tie rod clip. Tighten the inner tie rod clockwise. Bend over the tie rod clips tab. Smear some common brown wheel bearing grease on the shaft. Slip the new boots over the inner tie rod and secure them to the rack. Put the rack back in the car by: inserting the universal collar attaching the steering shaft to the rack's pinion, tighten the bolt through the collar. Reattach the tie rods. Reattach the hydraulic lines (what is called the banjo fitting) to the rack using new copper crush washers (all Griffiths racks come with new copper crush washers and tie rod clips). Tighten everything up and check your work twice. You can "eyeball" the toe alignment until you get an alignment (schedule the alignment before you start the job). Refill the power steering reservoir. Start the car (make sure you have it safety in mind here) and turn the steering wheel slowing right and left, lock to lock, several times to bleed the air out of the rack. Recheck the power steering reservoir level. Drive down to the alignment shop. OR, simply hand over the replacement of the rack to a shop you feel comfortable with that has an alignment machine on sight ;>)