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Discussion Starter · #1 ·
After a year of being frustrated with my steering system, I've decided that it's time for a new steering box. No matter how many times I get an alignment done, the steering wheel is never centered. I have to apply counterclockwise force on the wheel to keep the car straight... if I let go, the wheel will straighten itself out and the car will veer to the right. Someone else on the forum described a situation in which guy with a Firebird had the same problem, and it went away after he replaced his steering box.

I read the article on B-Body.net about the Trans Am steering box, but I didn't entirely understand the ratio stuff... the SS's box has a 12.7:1 ratio, and my RM's ratio is 16:1(?)... does that mean that my car's steering is harder than an SS's steering? I find that a bit hard to believe! My steering is extremely soft, there isn't as much road feel as I'd want... and I have a Moog front end! When I was on vacation a week ago, I drove a BMW 318i, and really liked its steering... very resistant, and extremely precise. Road feel and driving confidence were two things it had that my car doesn't. Will the SS box do this for me, or am I looking at doing something else?
 
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Discussion Starter · #2 ·
Erik,

Perhaps if GM had hired some BMW engineers to design the steering... ;) I was thinking how interesting it would be to try to put a rack & pinion setup on the B-body....

As far as the difference in ratio, the 16:1 gear is easier to turn, as you have greater mechanical advantage--what are they teaching in college these days? :D (had to ask!)

All B-body cars have the same basic amount of full mechanical travel from stop to stop-- many Impala owners know about the tire hitting the front sway bar, and I'm not sure if this happens with the RM, with its narrower tires. The turns of the steering wheel from one end of travel to the other will vary by less than one full turn, since the full travel of the gearbox itself results in about 90 degrees or less of pitman arm rotation--a 16:1 gear should be less than 4 full turns "lock to lock", while the SS and 9C1 gear is under 3 turns, as I recall. I am also not certain about this, but there are "straight ratio" gearboxes, which I think the Impala is, and there are "variable ratio" gearboxes, which the RM may be. The result is that the variable gear has a "slower" ratio on center, and speeds up as the wheel is moved off center. I need to dig into the FSM on this.

There are potentially a number of problems with your current steering that should be considered first--

1. The RM has variable assist--at least I think it was standard. There is a variable resistor on the base of the steering column and a valve on the pump output that act to reduce steering effort in a manner corresponding to the amount off of straight ahead the wheel is turned. I would eliminate this as a source of the problem first.

2. Verify all of the mechanical connections are in good shape--tie rods, center link, idler, and intermediate shaft (between base of steering column and steering gear)--this last item has a flexible joint just below the base of the column that can and does get sloppy

3. Internal backlash adjustment of the steering gear sector (pitman arm) is out of tolerance

4. Spool valve in the steering gear is sick--this is the part that ports the oil in the gearbox to actually provide assist. This results in the amount of effort required-- there is a torsion bar that deflects to create fluid demand by creating a port opening to direct oil under pressure on one side of the control piston and open a drain port on the other side of the piston, and the degree of this deflection determines the level of assist. There are O-rings that can allow oil to leak by on one side or the other and cause the steering to sort of fight itself--you would see it as a tendency for the car to try to steer itself in one direction regardless of what you do to correct the problem through alignment.

A replacement of the steering gear might be a solution, but I am not sure if the variable output pump setup on the RM and a 12:1 gearbox are compatible--you might have to change to a standard PS pump, too.
 
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Discussion Starter · #3 ·
One clarification on my previous post, in item 4. The torsion bar size is varied, which determines the amount of spool valve deflection, thus the amount of hydraulic assist, and this is felt by the driver as either heavily assisted "light" (fingertip control) steering or low assist, with a heavier, firmer feel, requiring much more of a real grip on the wheel.

This all started back in the 2nd generation Firebird TransAm days, when Pontiac engineers (back when the divisions actually had some control over these things) decided they wanted to go to "firmer" steering--especially in the late 70's WS6 iteration. This philosophy came largely from Herb Adams' influence--as a GM/Pontiac engineer, he inspired much of the Pontiac "style" of suspension tuning. Chevy did follow suit eventually with a "firmer" gear for the Z28, and this did eventually "trickle down" to the 9C1 and Impala SS, ZQ8 S10, and other "special" vehicles GM has built over the years using the (Saginaw) 800 gearbox.
 
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Discussion Starter · #4 ·
I am just now going through the same thing with my wagon. I put in a box from a 1LE Camaro with the quick ratio and thick torsion bar. It had the big internal stops so turning radius was reduced too much. After a day or two I found the overly heavy steering a pain. I went through the boxes I had around and found many are 12.7 constant ratio but with various torsion bar rates. I have now settled for a mismatch of parts that are mostly 98 Jeep ZJ. (Saginaw is everywhere) It is the 12.7 but a lighter torsion bar than the 1LE and heavier than my original. The stops are about 1/8 (original had none) and the steering will just about touch the susp stops with them. The steering is still much heavier and quicker than before. I have not quite got used to it and may ultimately put the original control valve back in with the 12.7 rack. How heavy is right is a very personal thing and I would recommend you hook up with someone that has the heavy box to try before doing. Likely you will like it but might want to test one first. I would recommend you do all the other susp stuff first as loose parts are going to make the car lazy and sloppy as well. If you do the box after you will only need to reset the toe.
This is a good page to help identify boxes. http://jeffd.50megs.com/steering_box_internals.htm
 
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Discussion Starter · #5 ·
Thanks for all the replies. Bill, your posts, as always, are very informative! I had no idea the steering system was as complicated as you described it
. As for what they're teaching in college, I'm still a first year engineering major, so I haven't gotten into the hardcore (AKA fun) stuff yet. ;) I knew the ratio had something to do with force input/output... just wasn't sure what the inputs and outputs actually were... Whether it was 16 lbs of force to move the wheel itself, or 16 lbs of force applied by the steering box to the pitman arm. So now that that's cleared up :D...

I'm sure I will enjoy a heavy steering. Right now, I'm having to hang on tight to the wheel and constantly make adjustments to keep the car going straight, along with fighting the wheel's tendency to straighten out
. It's driving me crazy!(pun intended) In the BMW, I could center the wheel and let go, and the car would keep going straight, even down a bumpy road.

I'll check out the condition of the box I have now the next time I have the car up on jackstands. Is it hard to get the box off the car? This is probably one of the only parts of the chassis that I haven't messed with yet. I'm pretty sure that something is up with the box... yesterday when I was driving the car, I drove with the stereo off(not something I do very often ;)). Everytime I turned the wheel, I heard a high-pitched squeek that sounded like something was rubbing behind the steering column.

95wagon, did the box from the 1LE bolt right in? Might be something I'd like to try out. What exactly does "quick-ratio" mean? Less turning of the wheel from lock-to-lock? By turning radius being reduced, you mean that of the steering wheel, not the front wheels of the car, correct? I can't make a smooth U-turn without 3 lanes to turn into... I'd be ashamed to drive the car if it needed any more turning space than that! :D
 
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Discussion Starter · #6 ·
Erik,

I feel your pain. I have not driven a BMW, but I have driven vehicles with the rack and pinion steering. Both, my mother and father, own vehicles with rack and pinion systems. I'm always tickled when I drive their cars, the feel and precision is night and day better than my 9c1. The vehicles I speak of are, '93 Mazda MX-6 and '97 Dodge Dakota. I think it's funny how a truck can drive better than a car.

I too find myself having a hard time keeping the car going straight w/out having to do a LOT of correction. I know, I know, check all of your front end components, but what is there to check when just about everything has been replaced. But I am curious about the intermediate steering shaft. How do you check that? I still think it's the tires. *sigh*
 
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Discussion Starter · #8 ·
“Quick ratio” is in regards to the difference in the input to out put of the box. 12.7 ratio means the steering wheel turns 12.7 times faster than the sector. Imagine the steering could turn endlessly,,,,,,, If you turned the wheel 12.7 turns the sector would turn 1. Another way to look at it is three turns at the wheel is 1080 degrees. Divide by 12.7 and you get 85 degs. This is the amount (near a quarter turn) the sector will turn if you turn the wheel 3 turns. The internals (check the web sight) are like a screw. The 16-1 is a finer thread than the 12.7 so you must turn the wheel more to get the same movement.
Now as for ratio being responsible for how many turns are in the box that is not really true. You can have a 2.5 turn box that is slower than a 3.0 depending on stops. Out of three 12.7 boxes I have here (94 9C1, 90ish 1LE, and the Jeep XJ) they all have different internal stops. The 1LE is 2.2, the Jeep is 3 and the 9C1 is 3.5. The big difference is the torsion bars. The thicker it is, the more effort you most put in before the bar deflects and the spool moves and adds boost.
If you read my first post, as of this morning I was running 12.7 ratio with small stops and a moderate torsion bar. This netted me 3 turns in the box and hand over hand parking. The stops work well with my SS wheels and tires just touching the sway bar lightly. I guess I am getting old cause I took it back apart after work. I now have my original torsion bar with the 12.7. So it is now not unlike the SS- 9C1 box. I have other cars with the heavy torsion bars and this car is my driver. It is now nice to drive with the ratio faster but the effort near stock.
As for your turning radius (yes the 1Le is a drop in), you would need to remove the internal stops so it would turn the same amount. I am fortunate to be able to do this sort of thing my self so trying different combos does not really cost me anything. If you did choose to go with the heavy "F" box you would need to have some one remove the upper internal stop and replace the lower cover (which acts as one of the stops) with your original to keep the full travel you require. Playing inside steering boxes is not for everyone and one mistake could be deadly, so if you are not 100% confident get it done by a professional. One misplaced rack ball could go unnoticed and lock the box solid at a more inopportune time. Regards, Gerry Charlesworth
 
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Discussion Starter · #10 ·
SSRM -

You say your steering wheel is not centered after an alignment... get a new alignment tech or go back and make him center it.

This is done by adjusting the tie rod sleeves and has nothing to do with the gearbox.

As far a wander goes.... our fronts are way too large for this car. They push and scrub in corners. Should be much narrower for proper control... Our wide tires act as rudders and if you put bigger tires on you just make it worse.

The BMW you drove had the properly sized tires for the ultimate driving experience.

Ours are designed to look cool... and they do it very well. That is why we bought them.

If you are autocrossing they are great, if you are doing normal driving they can wear you out with wander. Does make you pay attention tho' don't it?

If you want great handling, go to a narrower tire up front.

Another tip is to run 42-45 lbs of air in the front otherwise the center of the tire is missing the road and the wide outside edges are dragging you where they want to go.

I also run 40 in the rear unless racing - then 46 seems to be right for all across burn on the RE730s

just my .02
 
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Discussion Starter · #11 ·
<BLOCKQUOTE>quote:</font><HR>Originally posted by uwsacf:
As far a wander goes.... our fronts are way too large for this car. They push and scrub in corners. Should be much narrower for proper control... Our wide tires act as rudders and if you put bigger tires on you just make it worse. ...

If you want great handling, go to a narrower tire up front.

Another tip is to run 42-45 lbs of air in the front otherwise the center of the tire is missing the road and the wide outside edges are dragging you where they want to go.

I also run 40 in the rear unless racing - then 46 seems to be right for all across burn on the RE730s
<HR></BLOCKQUOTE>

Hmm, what width wheel would you recommend running? I'm having the exact same problem with front-end wandering; and it's with my "thinner" 9C1 wheels! :D Maybe I just need more air in the tires.
 
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Discussion Starter · #12 ·
<BLOCKQUOTE>quote:</font><HR>Originally posted by uwsacf:
SSRM -
our fronts are way too large for this car.
<HR></BLOCKQUOTE>

I thought the Titanic hit an iceberg because its rudder was too small? :confused:
My cornering right now really sucks (with 235 all around), but it's probably most due to the fact that I currently have no rear sway bar ;)

I am quite sure that my steering box has a problem... in the past, when the steering wheel wasn't centered and I let it go while in motion, it would stay off-center and the car would keep going straight. Now, if I let go, the wheel will straighten and the car's path will curve. I would like to go with a lower-ratio box anyway, though, so I might just go ahead and do it... hopefully my problems will be solved. If not, time to find yet ANOTHER alignment tech :(
 
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Discussion Starter · #13 ·
That sounds more like cord set causing a tire lead.
It is very easy to decide between the tires or the steering gear causing a pull.
Get the car up to about 40-50 on a flat road and note the pull. Now put in neutral and shut of the engine. With the engine not running the steering box can’t make it pull. So if the pull is the same likely it is not the box. If the pull is reduced–stopped or if the wheel twitches when you restart (still rolling) you have a box problem. If you move the tires across the front and the pull stops or goes the other way, tires are likely to blame. Picture an ice cream cone rolled across the table. Some tires will do that even brand new. Caster and camber will of coarse cause pulling but the deal where you hold it the other way, let go, wheel straight, then car goes, is typically tires. Alignment problems usually are more a “hold the wheel straight” deal with out that odd pause between motions. Gerry
 
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Discussion Starter · #14 ·
I think Gerry is right about the bad cord. One guy in the CarISSMA group had the same problem. He would have to hold the wheel straight going down the highway, as soon as he let go it would veer off. Determined it was a bad tire.
 
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Discussion Starter · #15 ·
Actually, the guy who did my alignment said that one of my tires was out of round, but would straighten out over time.... I had the tires rotated, which I thought would fix the problem.
when I took it back to the same place last Wednesday, they checked the tires on a machine and said they were all good.

I'll find a stretch of empty road and do what 95wagon suggested. If it is just a bad tire, then it's in good timing... I have some SS wheels on the way :cool:
I still want to move to a lower-ratio box, but if it's just a tire, I'll put the box change off for a month or two.
Thanks for all the help guys.
 
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Discussion Starter · #16 ·
I'd say, wait till you get the new tires on there, if that doens't fix it, then get a new SS or 9C1 steering box (same box) and unhook any variable assist stuff. Leave the Buick steering damper on the centerlink though, it will help prevent wander on the highway.
 
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Discussion Starter · #17 ·
It's funny how everyone calls it the Buick steering damper, yet my Buick didn't come with one


When I got my moog parts last November, I had heard a bit about the damper, but had reservations about using it, so I went ahead and got the centerlink without the shock mount for the damper. Might not be a bad idea to install it after getting my fatter meats on...
 
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Discussion Starter · #18 ·
Keep this up as I am a little behind. I too have had the "non centered" streeing wheel problem. It has been to 6 shops and it can not be centered. The passangers side tie rod bottoms out before the wheel is right. Can the tie rod be cut down? LMK!
 
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Discussion Starter · #19 ·
If you have a tie rod way shorter on one side than the other you have BIG problems!
If you are lucky, some how the steering wheel is off center from the box. This is tough cause the shafts have indexing but I have seen intermediate shaft assembled 180 out and rag joints crammed on wrong over the input flat. In most cases (I work in the collision industry) I have found the problem to be damaged steering linkages or a diamond frame causing the rear axle to not be true causing dog tracking. The first thing to check is if the center link is centered in the car with the steering wheel straight. Lock the wheel dead center then measure from the left inner tie rod to the right control arm bolt and vice versa. The measurement should be the same give or take. If it is more than half an inch different you need to look at the box and related parts. If the car has been crashed or curbed big time the sector shaft in the box could be twisted. This is a VERY common occurrence that gets missed. If you drop the outer tie rods so the steering stops do not come into play you can find the center of the box. Half way between the stops (full lock each way) should be center on the wheel. If it is not something is amiss. If the wheel is upside down something is assembled wrong. I have seen rebuild boxes that had the input 180 out causing grief. If the wheel is centered with the box in the middle, the problem is further down the system. With the wheel straight, the flat on the box input should face up and the center link centered in the car. If the flat is up and the center link is off to one side there is a very good chance the sector is twisted. Another thing to look at is the steering arms. They should be the same distance from the rim edge each side If not, you may need a new steering knuckle. Sorry to be so long winded but it is harder to type this (for me) than to actually check a cars steering. Regards, Gerry
 
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Discussion Starter · #20 ·
Well, I finally did the test... turned the car off while cruising down hwy21 at 60mph. I had to fight the wheel to keep the car going straight, so that probably means that one of the front tires is out of round. :(
Got a fix coming in soon though, thanks to Nick @ Maco Performance :D
 
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