Steering Shafts & Couplers

What are steering shafts and couplers and where are they located? 

The intermediate steering shaft connects the steering column shaft to the steering gear box input shaft.  When you turn your steering wheel, the steering column shaft turns with it.  The steering column shaft, in turn, spins the intermediate steering shaft, which spins the steering gear box input shaft.  That moves the steering gear, whether you have rack and pinion steering or recirculating ball steering, to move the tie rods, turn the wheels, and steer the vehicle. 

The intermediate steering shaft is a simple part, but it plays an important role.  The shaft is just that, a metal rod.  In many cases it comes with universal joints—called steering couplers—at either end.  These connect the shaft to the steering column shaft and the steering gearbox input shaft, allowing them to join at an angle.  That means that the shafts don’t have to be aligned in a perfectly straight line.  If they do line up straight, they will be connected with a rubber disc called a rag-joint, rather than a universal joint.

Steering couplers, on the other hand, help connect the various parts that link the steering wheel and allow you to steer your car.  When you turn your steering wheel, the steering column shaft turns with it.  The steering column shaft, in turn, spins the intermediate steering shaft, which spins the steering gear box input shaft.  That moves the steering gear, whether you have rack and pinion steering or recirculating ball steering, to move the tie rods, turn the wheels and steer the vehicle.  Steering couplers connect the steering column shaft to the intermediate steering shaft, and the intermediate steering shaft to the steering gear input shaft. 

There are two main forms of steering couplers used:  universal joints (u-joints) and rag joints.  A u-joint can turn at an angle, which means that the steering shafts don’t have to be aligned in a perfectly straight line.  If the shafts are lined up straight, they can be connected by a rubber disc called a rag joint.  The rag joint allows for some flexing between the different shafts.  It also allows for a slight amount of flexing between the body (which the steering wheel is attached to) and the frame (which the steering gear box is attached too).  A rag joint also absorbs some of the vibrations from the road that would otherwise be felt in the steering wheel.  

How do I know if my ­­­­steering shaft and couplers need to be replaced?     

The steering shaft couplers are more likely wear down than the shaft itself.  The joints can wear down overtime and become loose.  That means that the input from the steering wheel isn’t perfectly translated to the steering box.   It is also possible for the shaft to come loose from the joint as the shafts splines deteriorate.  This too will result in loose steering.  You may notice slack or sloppiness in the steering.  Worn joints also tend to make noise.  Listen for a clunking or popping noise, especially one that’s present when you turn at low speed.  A steering shaft can also become damaged or misaligned in a car accident, which will again make you steering less exact.  A loose or damaged steering shaft not only makes driving difficult but can be a major hazard.  The joint could give way as your driving, leaving you unable to steer at all.  It’s best to take care of any steering shaft problems right away.

Steering shaft couplers can simply wear out over time and become loose from use.  If this happens, the input from the steering wheel isn’t perfectly translated to the steering box.   You may notice slack or sloppiness in the steering.  Worn joints also tend to make noise.  Listen for a clunking or popping noise, especially one that’s present when you turn at low speed.  Rag joints can wear out over time, or from exposure to heat or engine oil.  A loose rag joint can result not only in sloppy steering and noises, but also in a vibrating steering wheel.  That’s because the rag joints ability to dampen vibration becomes compromised as it wears out.

A loose or damaged steering coupler not only makes driving difficult, but can be a major hazard.  The joint could give way as your driving, leaving you unable to steer at all.  It’s best to take care of any steering coupler problems right away.  

Can I replace the steering shaft and couplers myself?  

Replacing a steering shaft can be a bit tricky, but should be within the grasp of an experienced do-it-yourselfer.  Since the shaft needs to be lined up correctly, you’ll want to straighten out the wheels and the steering wheel before you begin.  Use a clamp or a steering wheel holder to make sure the steering wheel doesn’t turn as you’re working.  That will also make removing the shaft easier. 

If you’re using a steering shaft that comes with universal joints, then, under the hood, by the firewall, pull back the rubber boot that covers the steering coupler.  Remove the bolts that connect the coupler to the steering column shaft first.  Then, further down, remove the bolts that hold the coupler to the steering gearbox input shaft.  Then you can pull the steering shaft up and out.  Reverse the procedure to install your new steering shaft. 

In the case of a steering shaft that does not come with rag joints, you’ll pull back the coupler boot, unbolt the shaft from the couplers, pull it out, and bolt the new one to the couplers.  In either case, be sure to reattach the boot firmly as it keeps material in the engine compartment out of the vehicle cabin, and helps to protect the coupling from wear.  

Replacing a steering coupler can be a bit tricky, but should be within the grasp of an experienced do-it-yourselfer.  The best way to replace the coupler is to remove the intermediate steering shaft first.  Since the shaft needs to be lined up correctly, you’ll want to straighten out the wheels and the steering wheel before you begin.  Use a clamp or a steering wheel holder to make sure the steering wheel doesn’t turn as you’re working.  That will also make removing the shaft easier. 

If your steering couplers are universal joints, then under the hood, by the firewall, pull back the rubber boot that covers the steering coupler.  Remove the bolts that connect the coupler to the steering column shaft first.  Then, further down, remove the bolts that hold the coupler to the steering gearbox input shaft.  Then you can pull the steering shaft up and out.  Then, you can separate the coupler from the shaft.  It might be attached with a screw or bolt, or might be fitted in by its splines.  Then, you can attach the new coupler and reinstall the steering shaft. 

If the coupler in question is a rag joint, you will unbolt the rag joints from the other steering shafts and pull out the intermediate steering shaft.  Pull the shaft up and out, and remove the old rag joint.  Bolt on the new one, and reinstall the steering shaft.