I want to start this by saying in my opinion if you use the factory service manual procedure to adjust the steering box you will be doomed with less then ideal steering "wonder ware it will go next"
Mazda went with a taper roller bearing on top of the sector shaft some time mid 1981. Previous to mid year 1981 Mazda used a needle bearing. The 14mm lock nut and adjuster on top of the sector shaft perform very different functions to adjusting between the two types of steering boxes. This combined with a FSM that is low on grammer, and a mix of both versions of the steering box can cause some issues.

The 14mm lock nut with the adjuster sets the preload on the taper roller bearing. It is fiddly and a PITA to do.
Here is how I do it. first disassemble and clean/inspect the steering box. And I mean clean all the threads on the adjusters.
I take the outer race with the four holes on top and thread it all the way into the cover. Take the the cover and place it on the box and thread in the three bolts by hand. Firmly snug down the outer lock nut (the thin on that locks down the outer bearing race). Now remove the cover with the outer race locked down in it. Lube up the bearing with gear oil. Put the sector shaft back into the outer race and take a flat screwdriver and wind out the center adjuster counter clockwise. Put the sector shaft/cover back into the box, thread in the three bolts. Now we adjust the preload on the sector shaft taper bearing. Turn the center adjuster with a flat screwdriver counter clockwise until it stops. Hold it and tighten the 14mm lock nut. Grab the end of the sector shaft that is sticking out of the box (the steering shaft and car are not in the box at this time) and try to turn it. If it turns real easy or you feel play in it there in not enough preload on the bearing. If you cannot turn the sector shaft at all its got to much preload. Counter clockwise on the adjuster increases preload on the bearing. It should take a real firm grip to make it turn and no play should be detectable.. This is the most important step in setting up the steering box.
Remove the sector shaft from the steering box and set it aside.
lube the roller bearings on the steering shaft and pour some in between the car and shaft (get some lube in the the recirculating part). Put the shaft/car back into the box and set the preload on it. I use a 7" vice grip on the steering shaft and set the preload to .5~.8 lbs with a spring scale. lock it down and recheck the preload (I use hylomar on the threads).
Center the car and put the sector shaft back into the box. Make sure you put sealant on the cover and that the center of the sector shaft is centered to the car. Torque the three cover bolts (IIRC 35ftlbs).
Put the pitman arm on and snug it down. If you grab the pitman arm you will notice a lot of play in it.
The adjuster with the four holes in it is what moves the sector shaft up and down and sets the preload between the sector and car. (on the early version of the steering box the small adjuster w/14mm lock nut moved the sector up and down). What I do now is use a pin wrench (after you loosen the lock nut) and thread it in until you feel in increase in resistance (you will not feel this if you are using a punch/hammer). Check for play in the pitman arm. If there is no play then check the preload on the steering shaft, if it went up .5~.8lbs from the previous your done. put the lock nut back on and recheck preload on the steering shaft.
When setting the sector shaft make sure the pitman arm is centered in its travel. I have found on the past three boxes I set up that the steering shaft preload is higher when the pitman is centered. Maybe Koyo ground the sector shaft teeth for tighter preload on the center tooth.,

If you adjust the play out of the pitman arm with the small adjuster (14mm lock nut) what it does is create clearance between the sector and the taper bearing. As you keep winding it down with the small adjuster the center line of the sector shaft will be pushed away from the car due to the taper cut into the teeth. As the sector shaft is pushed off its center line it will start to bind in the lower bushing. If you drive it this way it will start to take out the lower bushing and you will have play in the steering in as little of a weeks time. If the lower bushing gets really damaged the play cannot be adjusted out of the box anymore.

 

GOLD! Thanks rk970... just the kind of info I need right now

 

Great info here. I might have to archive this...

 

Yet another reason the SA is a superior version of the first gen!

Great writeup, looks like all the details are there. Would be nice to inline the pics with the
technical description to make it easier to follow.

I agree, this needs archived.

 

Jesus, please archive this. Thank you for the detailed how-to on this!

 

I do not know why mazda changed the design unless there was a problem with the early box needle bearing brinelling the sector shaft. The later box definitively costs more to manufacture then the early box. Had to be a reason to justify the cost.
The first time I adjusted the 81.5 > box was in 1991. Had a guy come in for regular 20,000 mile maintenance and check on his 1984 gsl. He had a complaint of excessive play in the steering. The rx3, isuzu trucks, chevy luv ect of that era had a single screw on top of the sector shaft for adjustment. Anyhooo
When I saw the four small holes lock nut and a cap on the small adjuster it was a wtf moment. I grabbed the FSM read it and was really like WTF.. It was a slow day at the shop so i pulled the pitman arm and yanked the sector shaft out. I Took it apart and it made better sense.
I adjusted the preload on the sector shaft taper bearing with the cover in a Big bench vise. Put it back in the box and set the preload between the sector and car... That car IIRC went another 80,000+ miles without having to adjust the steering box with less than 1/8" play at the steering wheel. (four tie rod ends, pitman arm and idler arm you will have some play). One other suggestion is get the MOOG idler arm.. and check all tie rods and ball joints also..
Rk

 

rk790, thank you for the great info! Would it be possible to take a look at the attached to place the pictures in the text that applies and repost please in word or the thread? I don't have a box open in front of me to try out the descriptions as I read them.

I can pull apart one of my boxes to get any additional pictures if needed to get this a bit more detailed.

Thank you,

By the way, can anyone confirm for me if the GSL boxes have a tighter turning radius vs the other models? Found some conflicting info on this.