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Discussion Starter #1
Gentlemen, I have excessive vertical play in the ZF steering box in my SS. I have removed the top cover to investigate. In order to do so I had to completely remove the adjusting screw locknut as the adjusting screw will not pull out of the shaft, it does, however, rotate freely. Also the screw never seems to adjust anything. I would have thought it would have threaded into the top cover so that when it was rotated it would move vertically relative to the rocker shaft.


Questions: Does the adjusting screw thread into the top cover? Should it easily pull out of the rocker shaft? Should I now have a beer and wait for responses?

Regards, Don
 

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Don, have more than one beer. The adjustment screw had a jam nut that locked it into position on the top aluminum cover. The cover was threaded.(have another beer) It acted on the top of the shaft to keep it from moving up and down. Usually, the steering wheel centered has the most play. The adjustment is TOO TIGHT if there is any binding at the ends of steering wheel rotation (lock). This is most easily checked with the front wheels off the ground. Tie rod ends are a common source of slop on the front suspension of the 101 cars. If the threads in the top cover are gone ( :eek: ), someone has applied a lot of torque to strip them out! If the lock nut is gone ( :confused: ), thats not good either. (have another beer) I believe the top could be repaired, but it might be easier to find a used top (or 101 parts box). From your discription, none of this sounds too good due to the possibility of metal in the steering box. (one more beer!) Keep us informed.
Best, :DGordon Raymond
 

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Discussion Starter #3
Gordon, thanks for the help. I thought I would pass on what I have learned so far to satisfy the curious.

First Phillips makes a very good IPA. Perfect for pondering steering boxes in the "summer" heat on the west coast.

Second, it pays to have a long if not good memory... I found an old ZF steering box amongst the brambles in a local import wrecking yard. The long memory part means it only took 20 minutes of searching, having been there before.

Third, the manuals have been translated from italian, duh... so when it states to slacken the lock-nut on the adjusting screw it really means remove it, or the top cover will never come off. (as an aside the Alfa manuals for the 60s cars are no way as close to entertaining as Datsun manuals of the same era)

Fourth, perhaps not never as I discovered my old cover had the adjusting screw threads completely stripped out. In fact the hole measures 14 mm, while the adjusting screw is 12 mm.

Fifth, the adjusting screw is held captive to the rocker arm by a circlip in my bramble-bush box while the original is still a bit of a mystery. It appears to be held in place by a "wavey" clip with no split. I am hesitant to remove it for fear of damage.

So where am I now? I replaced the top cover, adjusted the screw as per the manual, first at centre and then at 30 degrees off centre, but found the box so tight that the steering will not return to centre without assistance when exiting a corner. I doubled up on the top gasket but no change, the screw is at its loose limit and the steering is way to tight. Unless someone has a brilliant idea I think I will be ordering some bushing and doing a complete rebuild.

Don
 

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Hi Don,
Let me ponder this a moment. Meanwhile, contact Alfar7 here with a PM. Richard Jemison. He is as good (BETTER) a fabricator of the "not longer existant" as I, a great machinist, and the ultimate Alfa performance "fixer". I am sure he or I can come up with a simple and inexpensive fix. Did you compare the top covers before replacement? It is possible the damage was done by incorrectly shimming the bottom. This may still be repairable in the car. Get a note off to Richard ASAP and have him look at this thread and give an opinion. Meanwhile I'll look at one apart tonight. Best, Gordon Raymond
 

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Back again. I've seen one where the cover was removed, and the shaft lifted enough to 'loose" one of the balls. It actually jammed somewhere, not allowing the sector to drop fully down. Boy, this was 40 years ago. (?) I remember it came to me like that for reassembly with the top off, and after fooling with it awile, it all went back together correctly. Something is holding your sector up. I'll think some more. Best, Gordon Raymond
 

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Richard Jemison
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ZF Steering box

I`ll pull out one of the old factory repair manuals in the Ayem. Meanwhile stick with the beer. I have one in the spares for the spider. Will check into this, but in the meanwhile ponder that the removal proceedure :eek:might have allowed the rocker arm & shaft to move (up) and may not be in the correct position, causing the problem. More tomorrow.:rolleyes:
 

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Richard Jemison
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ZF Steering Box731600240 cleaning

I pulled the box apart cleaned & took pictures of the internals. Since my seals were still pliable I reassembled using high pressure grease (packed it full) as it won`t leak out.
The critical part of reassembly is to be sure the worm tooth, in the middle (& smaller) is at its shortest point engaging the roller. It happens that point and with the box level the keyway for the steering wheel was strait up. If your`s (keyway) is strait up & your wheels are turned then you have linkage problems. (Alignment) I suggest dropping the steering arm off to do the assembly so the roller assembly can be removed from the top. You can change the seals & wash the unit out with brake clean to demuck & clean the bearings.

This unit had the adjuster screw locked in with a "C" clip. I did not remove. Just cleaned in the parts washer, blew it out, and sprayed in LPS Red & Ready which is a penetrating lube that turns into High Pressure grease.

I reassembled using Permatex gasket maker not the gaskets after reassembling the shaft`s bearing retainer plate (that the horn & flasfer wires travel through) did in fact properly load the shafts bearings.. You do not need a gasket to clearance anything. Top or front.

With the steering shaft centered I screwed the adjusting screw down as tight as I could. You could feel the resistance to turning the steering shaft at the center point. I backed it out 1 and 1/2 turns, then turned it in 1/2 turn to insure the contact on the screw`s surface was "Pushing" the roller carrier & not pulling and leaving a gap it could move up to & leave slack. The steering shaft was tight at the strait ahead position, but when turned 1/4 turn it was loose as it is supposed to be, and more so, as designed by a full turn. I eventualluy loosened it another 1/4 turn , the point where any more allowed the steering shaft to be a bit "free" which I did not want.

Pics will continue on next post.
Hope this helps.
ZF Box & shaft assembly for sale!
 

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Richard Jemison
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ZF Steering box Cont.

Pics of assembly cont.
When you have finished and the unit is set strait ahead, reattach steering shaft to it. If it does not line up abjustment of the alignment shafts & links need to be corrected.
 

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World's fastest ZF gearbox rebuild (less R&R)

WoW Richard! You are FAST! :) I was just looking at mine, and yours is DONE!:confused:
Checking the parts list, these internal box parts are the same #'s between the SS and Giulia spider, so the rebuild should be the same. With your pictures, Don should be able to R&R his SS box without problems. With his spare parts set up, he should have plenty of spares and workable parts. Your discussion of the proper relationshop of the keyway and parts should easily enable Don to get his back together, working
properly. Thanks, as always, for the education:cool:! Best, :DGordon Raymond
 

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The wear takes place in the straight ahead position, and typically on full lock you get binding. If you adjust at the straight ahead position it gets very heavy at half and full lock each way. So, what have you done to establish the wear pattern in the screw? Photographs don't give any clue here, and frankly I am not certain how you measure wear on such a coarse thread, but this is where you problem lies I believe.
 

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You are correct Stewart, but with Don's unit, it seems incorrectly assembled as Richard mentions in his 1:35 PM post. His paragraph two of that post discusses the critical relationship between the roller and the SHORTEST point on the worm. Any other assembly will make the roller assembly too tall to get the top on. It will work, somewhat, but the internal relationship between worm and roller are incorrect. Richard, tightening the thing down as far as possible, shows the available LIMIT of adjustment. As he later mentions, loosening it up, prevents the binding at the extremes you mention, while still allowing the center "play" necessary to keep the roller from pounding flat spots on the worm. The central play then, seems designed in to prevent hammering the worm and roller, though as you mention, over time and much vibration some wear can probably be expected. Not being an engineer, most of this is opinion, though the early Ferrari units are a similar design, and after actually breaking one of those:)eek:) in an accident, I have learned that not only proper assembly and lubrication are necessary, but correct adjustment as well!
As far as measurable wear, the only things I have ever seen are normal wear on the roller, which can be seen in Richards photos, or flat spots on the screw from a bash,( I have a 275GTB part that looks like that:(!) or incorrect adjustment. These served Alfa well for many years. Best, :DGordon Raymond
 

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Richard Jemison
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More ZF

The wear takes place in the straight ahead position, and typically on full lock you get binding. If you adjust at the straight ahead position it gets very heavy at half and full lock each way.

This is really an incorect statement. You might get wear at the strait ahead position, but if adjusted out the worm & roller are designed for more clearance with every it is turned degree off of center. It will not bind when set with no slop at center. as you turn the wheel. It will get looser.
Don`s box is incorrectly assembled. That`s obvious. If not at "center' when adjusted that could happen in one direction only.
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and frankly I am not certain how you measure wear on such a coarse thread, but this is where you problem lies I believe.

You might get a small amount of wear, but not enough to be a problem, unless the unit has been wrecked. When the wheel is off center and under light loading, the roller will turn on it`s on, so it does not ride on the same place all the time on the worm at center. If lubed properly really won`t be any wear.

You don`t have to listen, but you won`t win the argument.
Perfect "Signature" Statement! I think I`ll add it!:p
 

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Richard,

This is an old post but may I ask a question.
Do you imply that with the ZF it is normal to have play in the sides when they are correctly set at the centre?

Many thanks

Max
 

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If you consider the function, if the system is tight in the middle where most wear is common, it will be dangerously tight at either extreme, full lock in either direction. Generally, you adjust the sustem (BOTH front wheels off the ground) for firm contact at turning extremes. If it has too much play in the center, it's time to begin replacing components from my experience.
 

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Max, you are correct.
The correct setup is for minimal clearance at "full ahead" that is what RJR calls the shortest point of the worm. Chassis dynamic loading takes care of the increased clearance when turning off center (centrifugal force and tyre vectors), the center high-spot allows for wear adjustment which, as Stuart notes, will occur mostly near center. When correctly set up, THERE IS INCREASING RADIAL SLOP ON EITHER SIDE of the worm 'short' ahead position, gradually increasing form nil at center to quite a bit at full lock. This is NORMAL, not a fault and will not be sensed during driving. It is designed for heavy oil, not grease or gelatinus "steering lube" and will reward the driver with delightfully sensitive precise steering when correctly set up with 155x15 radials!
Ask me how I know,
Laurence
 
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