Before you consider rebuilding your classic’s steering box make sure the rest of the system is in good order

Tie rod ends should be in good shape, as should the Pitman arm and the other bits that go into the steering gear. Also make sure your car’s tyres are properly inflated. Then try adjusting your steering box according to your car’s shop manual before you go to the trouble of rebuilding its steering box.

To rebuild a basic steering box you will need to remove it from the car. On early cars with floor shifts, the job is easy. On later cars it involves removing the panels around the column inside the car and disconnecting the shift linkage. Check your shop manual to determine the best way to do this.

Removal sequence

To get the steering column and box out, remove the steering wheel. You will need a steering-wheel puller but, before you pull the wheel, disconnect the horn wire at the base of the steering box. Then attach a two-metre length of sturdy string to it.

Remove the horn button. Often you can get it out by pressing it in and turning it a quarter turn. Other horn buttons come loose by detaching screws from behind. Usually, the horn wire is attached to the horn button. Pull the horn button up so its wire comes out of the tube. Untie the string and leave it in the steering column. (The reason for the string is so you can thread the horn wire back down through the column and box and out the bottom when you put the steering box back in.) Remove the horn contact ring and spring.

Mark the steering wheel and steering shaft so you will be able to align the steering wheel when you put it back on. Attach the steering wheel puller and slowly tighten it. Beware — steering wheels can come off with a lot of force. Remove the spring and small bearing at the top of the steering column jacket.

Get under the car and disconnect the steering connecting-arm. Next, mark the Pitman arm and cross shaft so you will be able to put the Pitman arm back on correctly. Remove the Pitman arm. A gear puller will usually do the job, or you can use a bar made for separating ball joints. Unbolt the steering box from the frame of the car.

Down to business

Clean the box and wash it with solvent — this avoids getting dirt in the bearings and bushings when you open the steering box. When everything is clean, grip the box in a vise by one of its bolt pads so it is approximately level. Remove the steering column jacket tube and clamp.

Remove the plate that covers the Pitman arm shaft on top of the steering box casing. Save its gasket so you can cut a new one later. Wrap the splined end of the sector gear shaft with electrical tape to prevent damage to the seal in the casing. Lift the sector gear shaft out the top of the box. Remove the end plate from the casing and pull out the bearing cup and lower worm gear bearing. On some makes there will also be an adjusting sleeve that needs to come out.

Lift the sector, or roller gear out through the top of the case. Pull the worm gear and steering column out through the end of the case.  Inspect the worm and sector or roller gears. If they are chipped, pitted, or worn you will need to find a new, or good used set from another box.

The sector gear or roller is integral to the shaft on most designs so you will need to change out the complete assembly. The worm gear is usually keyed to the steering shaft and can be pressed off using a bearing press, or get a local machine shop to press it off for you.

Next, look the worm gear bearings and cups over for pitting and wear. The races should be free of discoloration and the bearings should turn freely. The bearings should also be held firmly in their cages. If they aren’t, replace both the bearing and outer cup. In some cases, the inner bearing race on the steering gear is cast integrally with the worm gear.

If you need to change the outer bearing cup for the upper worm gear bearing, you will probably need to have a machine shop pull it out of the steering box casing for you. It is usually pressed in, and difficult to get at from behind. While you are at the machine shop, have them press in the new bearing cup as well. Don’t use a new bearing in an old bearing cup though.

Bearings and races are machined to work as a set. Finally, check the bushings in the Pitman arm shaft housing. If they are worn or damaged, have a machine shop press in new ones, then burnish them to fit the Pitman arm shaft.

Reassembly

Check the steering column seal in the upper end of the steering box casing. If it is damaged, replace it. Smear a little gear oil on the upper worm gear bearing and slide it onto its race. Carefully slip the steering column back up through the seal in the upper casing. If there is an adjusting sleeve in your steering box, put it in now. Oil and install the lower worm gear bearing and cup.

Coat the mating surfaces of the worm gear end plate with sealer, then press on a new gasket. If your steering box employs shims for adjustment, slip them over the horn wire string now. Thread the horn wire string down through the tube in the worm gear end plate. Tighten the end plate evenly into place. Oil its bushings, then slip the Pitman arm shaft down into the steering box casing until its gear or roller engages the worm gear. Install a new gasket and tighten the cover into place.

Carefully slide the steering column mast jacket onto the column and tighten its clamp. Put any felt oiling pads in place, then install the upper steering column bearing. With the steering box still in the vise, temporarily install the steering wheel, then adjust the worm and sector gear lash and end-play according to the instructions in the manual. Install any shift linkage that needs to be added before putting the steering box assembly back in the car.

Bolt the steering box loosely to the frame. Now get inside the car and loosely install the steering bracket. Put the steering wheel on temporarily and turn it all the way to the left until it stops, then all the way to the right. This is to relieve any binding in the system. Tighten the steering box and column bracket into place making sure that the column is properly aligned.

Put any shift linkage back on, then install any jacketing around the steering column. Make sure the front wheels are straight ahead. Then, using your reference marks to orient it properly, slide the steering wheel onto its splines.

Tighten down the steering wheel nut.

Slip the horn contact cup, insulator and spring onto the horn wire. Tie the string hanging out of the steering column to the horn wire, then get out of the car and pull the horn wire down through the column and out through the end plate. Rotate the horn button into place. Reattach its wire to the wire from the main harness.

Fill the steering box with gear lube, then take the car out for a test drive. If things aren’t right, fine-tune your adjustments to the steering box. If the steering wheel spokes are not quite lined up, you may have to remove and reinstall it so it lines up properly when the car is going in a straight line.

Finally, check your steering box whenever you service the car to make sure it is full of lubricant.

This is an exploded view of a typical worm-and-roller steering box. There are three basic types of steering boxes in older cars, and many slight variations on each of them, but the basic adjustments are similar
On some cars the Pitman arm shaft and worm gear end-play can be adjusted without removing shims. On many others, shims need to be removed from under the access plate
Circulating ball steering boxes require less effort to steer
On Ramblers as well as some other makes, you will need to loosen a bolt to replenish the lubricant in the steering box, because no filler opening is provided
Remove the lower plate, then ease the lower worm gear bearing race out of the casing. Remove the lower worm gear bearing
Mark the steering wheel in relation to the column before removing the wheel
Use a steering wheel puller to remove the wheel from the splined column
The worm gear bearings and races should be checked for wear and pitting
If sector gear shaft bushings are worn, new ones will need to be pressed in at a machine shop, then burnished to the correct clearance

Words & Photos: Jim Richardson