birksc

I finally have my '85 RX-7 whipped into shape. Took it to it's first car show yesterday. The only remaining issue is the steering box. Three inches of play take all of the fun out of it. All the steering components are new. Tried to tighten the nut, it made it worse. I understand there is nobody who rebuilds these. I also see that there a couple of online vendors that say they have these (new) in the range of $1,000. I'm wondering if anyone here would have a suggestion as to who would be a reliable source. Thanks!

Scott

Ckforker

Post in the wanted ads. They aren't cheap though. Did you go through the three adjustments on the steering box? Usually you can make it much better, but it's always going to be sloppy compared to R&P.

Seniorchief

Might want to give this company a call and see if they can rebuild your steering gear box.
(Manual steering gearbox rebuilders ? PowerSteering.com)
Here is another option, may be in better condition than your current box, and if nothing else send that unit to be rebuilt. These units are like Unicorns, so if you can get a reasonable quote for a rebuild and the eBay unit is a fair price you will still way below the $1000 range you usually see kicked around.
(https://www.ebay.com/itm/28442455675...8AAOSwvJxhJpCI)

j9fd3s

iTrader: (3)

+1, the Lemons car we built had a steering box that wasn't great, and i adjusted it and it got better, but still just ok. so i took another swing at it, and really got it way better.

i found that if you do the adjustment in order the results are better. i backed everything off, and then tightened the big nut and then the smaller screw, and its much better

birksc

Thanks, Ckforker. I actually had my mechanic do it. I gave him printed detailed instructions. I'm going to have to ask him if he did all of it, or just tightened the nut.

birksc

Seniorchief, thanks for the links. I emailed the rebuilder, I will see what they say. I've read somewhere that there's no parts available to do a rebuild on one of those.

mwpayne

Please post back your results! There’s a bunch of us out here likely in same boat.

birksc

Will do!

birksc

So, I'm looking into doing it this way. I have a heck of a difficult time finding someone to work on this. I did find a mechanic who will replace the box, as long as it doesn't need adjustment. So now I'm trying to find out if the rebuilt box is good to go, or does it need adjustment after installation.

Toruki

I believe the FSM wants it adjusted on the bench anyway so that's great...

http://foxed.ca/rx7manual/manuals/19...l_steering.pdf

birksc

Thanks so much!!! Thar's probably just the info I need to persuade a mechanic to replace the box (once I get it).

jkmcafee

I may have a steering box - off an 85 GSL-SE

Frogman

I have a theory as to WHY it has about 2-3 inches of play stock. As I was driving through the freeway I hit a small pothole and the wheel did in fact move, but not violently, and I was still in control despite clearly feeling my wheel pull left while I was heading every so slightly right ( so it went from having a right turn to turning enough to eliminate the play and push left) If the car had no play every single jolt would violently turn the wheel and quite literally turn your car into the direction the wheel got jolted too if you did not counter. This is no good for track use but if you daily drove this car you would get tired of having to fight the wheel and or get hurt by every single road imperfection. I have driven RNP cars with no power steering and the jolts CAN break your fingers and F you up if you are not careful.

birksc

Thanks. Are you looking to part with it? I'm guessing it's the same steering box.

TimNH

I can't help but think the box just needs to be adjusted correctly. My car had that kink of play when I bought it 25 years ago. I bought a used box at the bone yard but that is major work. The play will be removed by adjusting the large nut and can be done in the car. The small nut is like adjusting the large axle nut when you have wheel bearings in the hubs. It is only to preload the bearings. The large nut adjust the worm gears which is where the play is. The adjustment has lasted about 23 years and it's still tight.

birksc

So here's where I'm at. I've been to a number of mechanics, nobody wants to try to adjust it. I met a mechanic today who is able to replace the box, but was hesitant because it would be an interruption to his business. I understand, it's easier to do things like brake jobs on a three year old vehicle, in and out, done. After a bit of begging and name dropping, it looks like he's going to do it. So I ordered the box on Ebay. I will have it rebuilt (they say they can do it as long as there is no hard part damage). Once it is done, I will have my original box rebuilt and hopefully sell it to some poor soul like myself.

Toruki

Adjusting the box is super easy once you understand it. This is being said by a person who did not initially understand it . Note that I am completely ignoring steering shaft preload in the talk below, but on the bench that should be super easy to do. However, I am addressing the most crucial adjustments, the sector shaft preload and gearlash.

This is an excellent thread: https://www.rx7club.com/1st-generati...7-gsl-1114116/

The Theory of It

The adjustments are bearing "preload" and "gearlash" Let's first describe the how the thing works
This is what it looks like inside the steering box from the top.
When you turn the steering shaft the gear teeth on the left side (ball nut) move front to back and the gear teeth on the right (sector shaft) rotate cw or ccw. On the bottom end of the sector shaft is the pitman arm that drags the steering linkage left/right, thereby moving the front wheels.


Gearlash...
The "play" in the motion of the steering comes from the tightness (aka gearlash) in the fit between the teeth of the ball nut and the sector shaft. The lower downward that the sector shaft teeth are dropped into in the ball nut teeth, the tighter that fit becomes (they machined the teeth with the correct angles to do that). The tighter the fit, the less play BUT also the more wear.

Preload..
There are some big lubricated bearings that hold everything in place tightly but allow parts to rotate. The preload on those beaings is what makes the wheel stiffer to move. Imagine that the steering box is disconnected from the steering linkage and can move freely. Preload adjusts it so that motion is firm, loaded up enough to keep everything smooth and firm but not so tight that it just makes the wheel hard to move and wears out the bearing surfaces.

Practical Application

On the top of the steering box there are 2 adjusters. The slotted screw/14mm locknut does the preload for the sector shaft bearing and the big *** sector plug raises/lowers the sector shaft teeth into the ball nut for the interference fit minimizing gearlash.



The basic outline of what I did, with the box in the car:

- disconnect the steering linkage from the pitman arm (under the car), you need a ball joint separator
- lightly turn the steering wheel and distinguish the feel of the play and the preload as it exists before adjustment
- loosen the 14mm locknut and turn the slotted stud CW, which LOOSENS the preload
- loosen the big *** locknut and rotate the sector plug CCW which really slops up the gearlash
- feel the wheel and its extremely light turning motion
- set the preload on the sector shaft bearing by turning the slotted stud CCW, which pulls the bearing together. Not too tight.
- feel the steering wheel's movement: you should be able to move if with light pressure from your index finger, but it should feel more resistance than the extremely light feeling in the previous step (note that people sometimes use a spring scale to quantify the resistance, I did it by feel).
- tighten the 14mm locknut while keeping the slotted stud in its same spot that you adjusted.
- turn the sector plug CW a bit and slowly/gently check the feel of turning the steering wheel about 3 to 4 inches left and right. You should feel a distinct but slight change in resistance. This is the preload in the "dead zone" of the very loose gear lash.
- tighten the sector plug a bit more, check the feel. Keep doing that until you get the play down to the factory spec of about a 1/2 inch of dead zone ("play").
- tighten the big *** locknut
- mark the relative position of things with paint (like the yellow in my pic, and note that I've tightened my plug another few degrees but not the preload)
- drive it to check the feel and tighten more if need be. Use your judgment.

Don't over adjust the gearlash to be super tight. If you do it will be really tight and delightful for a short while but then get loose again due to over wear and will get out of adjustable range.

Ckforker

Excellent explanation! Thanks, it always helps me when I understand the, Why.

birksc

So, here's the current status. I bought the steering box on Ebay that Seniorchief had sent the link for. I sent it out to powersteering.com and had it rebuilt. I was only able (after much effort) to find one quality mechanic who can install it. Unfortunately, he is swamped right now, since he cannot get help at his garage. But he promises to do it in the spring. So I will give an update after the snow melts I suppose. Ugh.

Keith13b

iTrader: (6)

Re-Speed made a rack and pinion conversion for the FB's. I have one and love it. Like you, I kept adjusting the original until there was no more adjustment allowable. Search the forums for re-speed rack and pinion kits, as they state which rack to use. IIRC it is from a mustang. The kit was fantastic and well made. Installation was simple. Maybe someone is parting out their car and would sell it.

Good luck.

swbtm

iTrader: (2)

I think I have 3 spares out of the car already. Sounds like you've already got a repair path sorted. Pulling the column out of the car isn't too bad, especially if the plastic shear pin has already broken. Getting it out with the dash in place is possible, but having the subframe and engine in make it a little more of a careful threading of the needle.

birksc

Here's the update on this issue. I finally found a mechanic to install the steering box that I found on Ebay and had rebuilt by Powersteering.com. Problem solved! The car steers like new! I just can't believe that it's so difficult to find someone to work on these. Maybe that will change when all the free money runs out. Anyway, now I have a steering box to sell to someone who wants to send it out for a rebuild to use in their own vehicle.

KansasCityREPU

iTrader: (9)

What free money? Can I get some?

Maxwedge

iTrader: (1)

yeah, I wanna know too. I haven't gotten any checks, and every winter when I file unemployment for 4-6 weeks I never get a check either (3 years running now). I'd like to know who these "rich" poor people are, because I've never met one.

Toruki

That's great. Did they describe the rebuild process? Was it just rubber seals and an adjustment or do they refurbish/machine bearing surfaces, teeth etc.? I suppose the cost is variable, but a ball park number would be appreciated if you're willing to share that information.