Gear box adjustment question

[big66440]

I was wondering if anyone has tried adjusting the preload adjustment on their steering gearbox like done on the zj's? I have researched a solution to the wandering at highway speeds that's very common on Jeeps and was able to pull that up, will that adjustment work on our steering gear boxes? BTW I have replaced every single bushing and ball joint, tie rod end I have brand new tires ( Good Year Wranglers 235/75 15's) and have done an alignment myself all within specs.

[Jeep Driver]

Did the Goodyears come from Walmart?

 

If they did.......so did mine and I took them back.

 

They suck.

 

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[dasbulliwagen]

Usually if there's enough play in the steering box to ask about adjustment, you just need to get a rebuilt unit. If you adjust for the wear in the straight ahead position, the area that gets the most wear, you'll end up having binding of the gears when the box is turned out to areas of little wear. That adjustment is mostly just there for initial setup.

[Strokermjcomanche]

Yep, get a rebuilt unit as dasbulliwagen said or a nice low mileage box out of a jy .

[nitroxsteve]

What is your caster set to?

[HOrnbrod]

^^ This
 

...and have done an alignment myself all within specs.

So what was your caster measurement on each side?

[Eagle]

Usually if there's enough play in the steering box to ask about adjustment, you just need to get a rebuilt unit. If you adjust for the wear in the straight ahead position, the area that gets the most wear, you'll end up having binding of the gears when the box is turned out to areas of little wear. That adjustment is mostly just there for initial setup.

I disagree. I've adjusted any number of steering boxes, and had only one box that was so trashed that it couldn't be improved by adjustment.

 

However, the OP asked about "preload," and I'm wondering if that's what he really meant. The XJ and MJ boxes are the same as the ZJ box except for the ratio. They are a basic, GM Saginaw steering box. They have two adjustments, a worm bearing preload adjustment and an over center lash adjustment. I've never touched the worm bearing preload on a steering box in over 50 years of playing with them. The adjustment I usually make is the over center lash. This adjustment is made with the steering gear (which hopefully also means the steering wheel) in the straight ahead position. Before doing this adjustment, park with the steering straight ahead, turn off the engine but DON'T lock the steeering wheel, and see how much (if any) free rotation there is in the steering wheel. If you can move the steering wheel back and forth more than about 1/8 of a turn in each direction, you may be a candidate for a lash adjustment.

 

The adjustment is the recessed (Allen head) screw in the top of the steering box, in the cover plate that's held on by three bolts. Put a box wrench on the locknut (I think it's a 14 mm or 15mm IIRC), put an Allen wrench in the adjusting screw to hold it in place as you loosen the lock nut, then loosen the lock nut.

 

Once the lock nut is loose, you adjust the steering lash by turning the adjusting screw into the box. Be careful -- a little goes a long way. Turn it no more than an eighth of a turn, then check the steering wheel again. What you're aiming for it to take out ALMOST all the free play. If you over tighten it, as Dasbulliwagen posted, you'll destroy the box. [Not, however, for the reason he stated. In fact, the lash is tightest at the straight ahead position, which is why you adjust it there. It's looser when the steering is turned, so if you adjust it off-center, it will bind across the center and that's what destroys boxes.]

 

Once you have ALMOST all the play adjusted out, sock down the locknut again and you're done. Just remember -- these are old-fashioned, recirculating ball steering boxes. They are NOT rack and pinion steering, and they will never be as tight as a rack and pinion steering gear. If you are judging your steering compared to a modern rack and pinion vehicle -- don't. You can't get it that tight ... period. There MUST be a small amount of lash in the over center adjustment to prevent binding up the steering box.

 

However, +1 (+2?) on the caster. I picked up a 2001 XJ for my daughter. Steering had a lot of slop in it. I replaced all the tie rod ends and adjusted the box. Had it pretty good. Then I corrected the sagged rear springs. brought the back end up about 1-1/2" and now it wanders like crazy. That rear lift reduced the camber in front by about 1 degree, and I think that was enough to induce the wander. I need to shim the LCAs, but it's too cold to even think abut that until Spring.

[Guest]

^^^ Super solid advice. Been meaning to look up exactly how to adjust the box, because I believe mine needs an adjustment here soon.

[HOrnbrod]

http://comancheclub.com/topic/35244-saginaw-power-steering-gear-box-technical-reference/

[big66440]

Thank you very much for that write up Eagle, I don't have the print out of what the specs where on the caster but I remember they were at approximately 7.2 or 7.3 ish and equal both sides, I got the tires from the shop I used to work in ( Good Year dealer) I understand it will never handle as tight as a rack steered car I've never personally owned one before so I'm familiar with gear box steered cars I just feel it could be tighter.

[Rockfrog]

Another thing to look at when sourcing steering slop is the intermediate shaft (from firewall to steering box) ... Any play there will be magnified by the steering gear.

[dasbulliwagen]

When I did my caster I found the spec to be " 6.5 to 7.5 degrees positive " I had a hard time getting close to that going from stock 2.5 2wd to stock 4wd springs with an additional spring isolator. I just about maxed out the adjustment just to get to 6 degrees. It did help tremendously though. Make sure you do that part.