Steering box

[nettxtra]

I have slark in the steering box, can this be tightened up or must I replace it?

[mdrburchette]

They can be adjusted to take up some of the slack. It's not the easiest thing to get to, but there's an adjusting screw with a set nut on the top of the steering box. Someone here should pop up shortly to give you directions on setting it properly.

[baltobernie]

Various shop manuals state that the steering box should be removed and adjusted on the bench, but many folks do it in situ. Fiat probably wanted the box removed, because they used a square 8mm lock nut on the adjusting screw. This is the only example of this size/type fastener on the whole car! I've never found a source for a socket or wrench of this size.

Several POs before you have undoubtedly used an 8mm open end wrench, and have rounded off the nut. I had to resort to Vise-Grip pliers, though Mike B. has never forgiven me for this

You might want to think about removing the entire top cover of the box (which has conventional hex bolts), and freeing up the locknut on your bench. This would also be a good time to suck out the old lube with a turkey baster, and replace with fresh diff oil. You might even replace the locknut with a six-sided one, if you are really clever (I wasn't).

When adjusting the steering lash, don't try and remove every last bit of play. This is a worm-and-roller setup, not rack-and-pinion, so some play is not only acceptable, but essential. If you adjust too tight, you may find a combination of load and wheel position that will actually bind the mechanism. I can live with one-half inch of total play in the steering wheel.

[nettxtra]

Thanks

[mbouse]

with all the power invested in me by POPE, i hearby forgive you bernie! your sage advice to this forum member has removed your debt to Fiat society..

i found that the square headed, threaded fill plug is the only fitting on the car that appears to be SAE size and not metric. i'm stretching my memory here, but 5/16" comes to mind... and there is a four / eight pointed socket commonly sold that fit that plug. NO, i am not talking about the same fitting that bernie is. i'm talking about the fill plug, where new gear oil would be added.

might try just filling the box with 80/90 gear oil before you go to all the trouble of adjusting, bench testing or monkeying around with the settings... just a thought. these steer boxes go dry after a few decades, and sometimes the simpliest fixes are overlooked.

[Foster48x]

i found that the square headed, threaded fill plug is the only fitting on the car that appears to be SAE size and not metric. i'm stretching my memory here, but 5/16" comes to mind... and there is a four / eight pointed socket commonly sold that fit that plug. NO, i am not talking about the same fitting that bernie is. i'm talking about the fill plug, where new gear oil would be added.

Mike's correct. I also picked up a 5/16 eight point socket from Sears for a couple of bucks that did the trick. Trying to get a open ended wrench down there without stripping the square bolt was nearly impossible.

Rick

[manoa matt]

I think you guys are getting the "square nut" confused. The little square plug is only the fill plug and has nothing to do with gear mesh adjustment, but yes, it is near impossible (with a tiny wrench) to get the plug out with the steering box in the car unless your intake manifold is removed.

Here is how to adjust the steering box: Make sure the wheels are pointing straight ahead and the steering wheel is centered. Jack up the front of the car so the wheels are off the ground and support it on jack stands. There may or may not be a small black plastic cap over the adjustment shaft and lock nut on the top center of the box, if so remove it. With a big flat blade screw driver and a 17mm wrench hold the adjustment shaft while loostening the 17mm lock nut. Completely remove the lock nut. Now remove the 4 hex head bolts that hold the cover plate on. Take the flat blade screw driver and hold the adjustment shaft while you spinn off the cover plate. The cover plate is threaded onto the adjustment shaft, hence the need to keep the shaft from spinning while removing the cover plate.

Now that you have the cover plate off you can safely remove the small square plug and change it out if you like, or just put some teflon tape on the threads and don't tighten it so much when you reinstall it.

Take a turkey baster and suck out all the old oil and replace it with 90wt EP gear oil. Hold the adjustment shaft from spinning and spin the top cover back on. When the top cover gets near the steering box housing you may need to turn the adjustment shaft to get it down and seated that last little bit and have the 4 holes line up. Install the 4 hex head bolts, and make sure the top cover is on tight, turn the adjustment shaft back and forth slightly to make sure the top cover is not binding it.

If I remember correctly on Europen steering boxes the adjustment shaft must be screwed up to tighten the gear mesh, while on American steering boxes the shaft must be screwed down. You want to adjust the box so that the steering wheel will turn 1 inch before you feel the shaft engage the gears and start to turn the wheels. A piece of tape or a known mark on the perimeter of the steering wheel will help to gauge how far the wheel travels. Once you got it where you think its good, install the 17mm lock nut and turn the steering wheel from full lock to full lock and note if you feel any binding anywhere in the travel. The binding or tighness will usually be felt as you are approaching full lock on each side.

Take it off jack stands and road test the car on a flat smooth straight road. Jiggle the wheel a bit as you drive to "feel" the gear mesh when it starts to engage. Tighten or loosten the adjustment shaft if need be.

You should do a good check of all the tie rod ends, center linkage, ball joints, and wheel bearings BEFORE adjusting the steering box. If you overtighten the steering box you can cause excessive/accelrated wear of the gears, after that the box can't be adjusted without a rebuild using new parts. Also check the steering idler on the passenger side for oil, it has three allen head bolts. Remove the cover then twist off the valve mechanism to fill with oil. An idler without oil will also make the steering feel loose.

[ventura ace]

With apologies to Matt, I will add a few comments, one of which are may not quite agree with Matt's experience and instructions.

As mentioned by others, it is best to make the adjustment with the steering box out of the car, since the friction in the ball joints, tie rods, etc. make it difficult to 'feel' the difference between steering gear binding and drag from the other linkages in the system. But, since taking the steering box out is extremely inconvenient, the method described by Matt is usually the next best approach. The steering gear is designed to have the least free play in the center, with increasing play as you turn the steering away from the center position, so it is very important to make adjustments and check for binding with the steering in its centered postition. If you make an adjustment away from center, to remove most of the play, then it may bind up as the steering is turned through the center region, which could cause some serious damage.

I usually adjust the gear so that it just barely starts to bind in the center region, then back off the adjustment just a smidge. As such, when you turn the steering to the outer extremes, you will experience about one inch or so free play at the steering wheel.

The fill plug can usually be removed by using an 8 point 5-16" socket as described by others, and may be almost impossible to remove otherwise. I would only take the top cover off, per Matt's description, as a last resort, as this may now introduce a source for leaks that was not leaking previously.

[baltobernie]

The little square plug is only the fill plug and has nothing to do with gear mesh adjustment, but yes, it is near impossible (with a tiny wrench) to get the plug out with the steering box in the car unless your intake manifold is removed.

Matt, you are absolutely correct, as usual. "Working from memory" just ain't workin'

[manoa matt]

I find its almost impossible to fit an oil fill tube down one of the tiny fill holes on the steering box or idler box. I've tried syringes, but it usually takes forever, or you spill oil all over everything else. You can "top up" the oil level in the steering box thorugh the fill hole, but if you want to suck out the old oil, then you need to take the top off.

If you fill up the steering idler through the fill hole then you will likely only fill up the small area between the cap and valve plate. You need to remove the valve plate to get oil down in the main reservoir below the valve plate.

As far as leaks go, steering idlers typically leak at the output shaft since there is no oil seal there just a friction fit bushing. The steering gear box typically leaks at the output shaft oil seal (pitman arm) and at the front shimmed cover plate. I believe the box should only be filled to within 1/2 inch from the top cover so no oil will be at the top cover seam unless its sloshing around.

[ventura ace]

Thanks for the tutorial, Matt. Since mine has always had a small bit of weeping from the top seam, it might suggest that I've got mine too full. I'll check it out. I'm sure that removing the top makes putting fluid in and out a lot easier. Your technique for spinning the top off while keeping the same steering gear adjustment is a neat idea.

Alvon

[Tango]

...If you fill up the steering idler through the fill hole then you will likely only fill up the small area between the cap and valve plate. You need to remove the valve plate to get oil down in the main reservoir below the valve plate...

I can't see anything in my two manuals on filling the idler, much less removing the valve plate. I see a cap plate with four screws on the perimeter and a central screw head that I was expecting to fill through. How do I get the valve plate off to fill more completely, or at least to see what is in there?

Tim

[tima01864]

Can not get that filler plug out, do not want to adjust the steering box. Will just taking off the cover as described be well enough?

[DieselSpider]

If you take the cover off you may likely end up having to adjust it anyways.

Note the most here only describe the cross shaft adjustment however the worm shaft also needs to be adjusted via the collar that screws in around the input shaft or you will be pushing the worm shafts bearing cones off center and wearing them elliptically.

You may be able to get the 8mm square plug out with an 8mm Crows Foot with a long extension on your 3/8" drive ratchet. Be sure to let some PbBlaster set on it for a few days first. If the plug is undersized slightly you may want to take a 7mm crows foot and adjust it to fit the plug exactly using a file or small grinder.

[tima01864]

Deeper and deeper, I will let the PB set in before i try again.