There seems to be no play in my steering box. How does one determine if it needs to be rebuilt or not?

 

check you private msg's section,,,,I sent you a contact person to fix you up with your issue.

 

There are lots of papers about adjusting your steering box. Here is a good one from Jim Shea. It's very easy to do. While you are at it, remove ONE of the lower cover bolts (one of three you are looking at when you look straight down) and check to see if you have enough lube. You can use a straw or a swizzle stick as a dip stick.

http://jimshea.corvettefaq.com/?page_id=4

 

If you have 4-5 in/lb drag, 11.5-12 on center, 005 or less sideplay you don't need a rebuild.
I'm willing to bet you don't if your box is original. Grease won't solve any of those concerns. If the lash screw is buried in the cover nut chances are the gears are shot.

 

If it hasn't been serviced in a long time, the grease in your steering box is either gone, caked-up, or a combination of those problems. The box sounds like it is functioning properly, but you likely need to get some lube into it. Jim Shea's papers and other search info will tell you how to lube it without taking it apart. I would recommend that you lube it with synthetic, hi-temp grease. It handles heat better and doesn't 'melt' and leak out of gasketed joints/bushings. Make certain that you leave a bit of an "air pocket" in the grease area, so that the grease can expand when heated.

 

Seriously though, before you spend any money, grease the box from the cover bolt hole and do the adjustments in the correct order as outlined in Jim's papers and then decide if you need to take the box out and rebuild it.

I used a siringe but a grease gun will work just as well but messier. The p/n you see on the tube in the pic is the correct GM part number available from any GM dealer for about $12-$15.

 

Thanks guys! I'll check it out and let you know this weekend!

 

The lash screw sticks out almost a 1/4 inch above the nut so I should be ok there. There is definitely a difference in the drag at the mid point so it looks promising. I didn't check the sideplay yet.
I have a inch pound torque wrench. I assume you torque the rag joint end but how do you get the wrench on and get a accurate reading?

 

Jack the car so both wheels off the ground, drop the power assist cyl nut off the frame end, make sure it don't drag on anything...then turn the wheel as you very carefully adjust the screw, make damn sure there is NO drag on the system, you can feel any binding on 'high center' which is primary wear point....

not to pay so much attention to any loose feelings on turns, as that is not too important...it's that center feel you after...

snug, but NO BINDING..

 

I can't do attachments so sorry for the long post but here is the correct way to adjust your steering box. Read "poor man's" method, it's the easiest and gives acceptable results.

C3 Steering Adustment
From Corvette Action Center

Corvette Action Center Knowledgebase
1963 - 1982: Technical Article: In-Vehicle Corvette Steering Gear Adjustment
In-Vehicle Corvette Steering Gear Adjustment by Lars Grimsrud
SVE Automotive Restoration
Musclecar, Collector & Exotic Auto Repair & Restoration
Broomfield, CO
Last Revised: 27AP2001
Vehicle Pretest
Before making any adjustments to your Corvette steering gear it is important to make a careful check of your
steering system and chassis components to assure that they are in good condition and not the cause or the
major reason for steering lash or looseness. Such things as; front end toe adjustment, tire inflation
pressures, condition of the flexible coupling, wheel balance, condition of the idler arm and linkage pivot
points, and even the shock absorbers can contribute to the complaint of steering looseness.
A Word About Lubrication
Use a good quality lithium based grease (ball joint grease in a tube.) Do not overfill the gear. It only needs to
be ¾ full. You need air pockets in the gear to allow for grease expansion with engine temperature. Also
there is a ball nut inside the gear that traverses back and forth when you steer right and left. You need air
pockets around the nut so that you aren't always squeezing grease back and forth around the nut and
causing friction in the gear. Last of all, some of the oils will separate out of the grease with time. Air pockets
in the gear help the internal motion of the gear components to mix the grease back up.
Some History and Background
It is important to understand that all Corvette steering systems from 1963 thru 1982 were essentially the
same. All of them started with a manual recirculating ball steering gear regardless if it was a manual steering
or a power assisted steering system. The power steering option just added a belt driven power steering vane
pump, a valve and adapter mechanism attached to the linkage intermediate rod, an assist cylinder (ram),
hoses to conduct the power steering oil, along with that same manual gear.
So regardless if you have manual or power assisted steering in your Corvette, the same procedures apply to
adjust the steering gear to eliminate steering lash and looseness.
A Point of Clarification: Some of the Chevrolet and Corvette Shop Manuals show a picture of a recirculating
ball steering gear with a worm adjuster nut and jam nut on the forward (in the car) side of the gear housing.
This picture is not the manual gear that is in your Corvette. The Corvette manual gear has the worm bearing
adjuster and jam nut on the input shaft (steering column) side of the gear.
The Corvette shop manual describes two procedures to adjust the manual gear. They are the only ones
sanctioned by Chevrolet. The first method on how to adjust the gear is to pull it out of the car and do it on a
bench with an inch pound torque wrench. The second way is to do it in the car but you must remove the
pitman arm and take torque measurements by placing a torque wrench on the steering wheel hub and
measuring gear torque through the steering column.
These two methods of adjusting the gear are fairly well described and documented in the Chevrolet Shop
1/4
Manuals (manual steering gear) and/or the Chevrolet Corvette Shop Manual and I do not believe that they
require additional clarification.
POOR MEMBER'S METHOD
A third way is to do it by feel in the car. The real concern when doing it by feel, is that overtightening some of
the adjustments can result in internal damage in the gear (which can be very expensive to fix.) Also,
overtightening can result in sticky steering and poor to non-existent steering returnability. In other words, the
steering wheel may not come back to the straight ahead position after making a turn and you will have to turn
it back yourself. Obviously, adjusting a critical system such as steering and driving the car to confirm the
settings must be done with great care!
One of the things that a lot of enthusiasts are forgetting (or don't realize) is that there are two adjustments to
reduce or eliminate lash on the manual steering gear. There is one on the input side of the gear (steering
column side) called the worm bearing adjuster and one that affects the gear mesh inside the gear called the
pitman shaft lash adjuster.
If you have a gear with worm bearing adjuster lash, you will not eliminate it by just tightening the pitman shaft
lash adjuster. Most likely, you have a 25 year old gear with a combination of input shaft (worm shaft) and
output shaft (pitman shaft) lash.
You must address worm bearing lash first. Worm bearing lash will show up as an axial movement of the
input shaft (in and out of the gear) as you turn the steering wheel clockwise and counterclockwise. This axial
movement is lost motion and will result in you moving the steering wheel with no movement of the road
wheels until the input shaft bottoms out against the internal gear bearings. You may even detect a small
polished area on the gear input shaft that will be an indication of it moving in and out.
Checking the Settings in a Brand New Gear
If you have a brand new gear and you are checking the settings, you will want to loosen the pitman shaft
adjuster lock nut and turn the screw a full turn counterclockwise to reduce friction from that location before
starting on the worm bearing adjustment. With a car with any appreciable miles on it, you do not have to
loosen the pitman shaft adjuster screw before starting to adjust the gear.
Worm Bearing Adjustment
What we are trying to do is eliminate worm shaft axial motion without adding unacceptable friction. First turn
the steering wheel all the way to the right corner and then turn back about one-half turn. Make the worm
shaft adjustment with the gear in this position.
Have someone rotate the steering wheel back and forth; look at the gear input shaft to determine if there is
any axial motion.
If you are doing this test without anyone to help you, try this approach. Unlock the steering column, grip the
flexible coupling with your hand and rotate it back and forth. Look and try to feel if there is an increase or
decrease of the gap between the flange and the face of the gear as you oscillate the coupling by hand.
If you have noted any axial motion or you are still suspicious that there may be some slight looseness
proceed as follows. Loosen the worm bearing adjuster locknut. You will probably have to use a blunt chisel
or a large punch to tap the nut counterclockwise. The nut is actually a stamping so the rolled over edges that
form the hex nut shape will allow you access for your punch. When you are done loosening the nut it will
probably be dinged up a bit and not concourse perfect any longer. Rotate the worm bearing adjuster
clockwise until it is snug but not tight. (Don't forget that corrosion, paint, etc on the adjuster threads can give
you some false indications that things are snug!)
2/4
Alternately tighten the adjuster then look and feel for axial input shaft motion until there is none.
The specifications say to tighten the locknut to (85 foot-lbs). Take care that when you retighten the locknut
that you don't cause the adjuster to tighten further. A helpful hint would be to mark the housing and the
adjuster with a piece of chalk or a crayon to insure that the adjuster remains in the same place when you
tighten the locknut. Carefully drive the car to check that the adjuster setting is not too tight and causing
returnability problems. Don't forget that during this driving evaluation you may still have lash because so far
we have only addressed one set of adjustments. Right now you are checking to make sure that your gear
adjustment to eliminate input shaft movement did not add unacceptable friction to the gear.
Pitman Shaft Adjustment Pretest
Once you feel that you have the worm bearing adjusted, you can now address the pitman shaft lash
adjustment. For this adjustment you need to place the steering gear right on center. Conduct the following
procedure. Turn the steering wheel from lock to lock, counting the total number of turns. Now, turn the
steering wheel back from full lock exactly one-half the total number of turns. For the most part, your steering
wheel should now be in the straight ahead position and your car should travel straight. If the steering wheel
is not straight ahead and/or your car does not travel in a straight path, you will need to center the rest of the
steering system before completing the gear adjustment.
Special Steering System Centering Procedure (If Needed)
After you have set your steering gear exactly on center (one half of the travel lock to lock), take a piece of
chalk or a crayon and mark the flexible coupling right at its top most position (12 o'clock.) This will now
indicates that your gear is on center. Now drive your Corvette a short distance on a flat surface in order to
determine the steering wheel and gear position when it is traveling a straight path. With the front wheels in
the straight ahead position, now check the mark on the flexible coupling. The mark should be at the right at
the top at the 12 o'clock position. If the gear has been moved off its center position you will now need to
adjust the tie rods to reposition the gear back so that the mark is again at the 12 o'clock position. Loosen the
tie rod adjusting sleeve clamps on both the left and right tie rods, then turn both sleeves an equal number of
turns in the same direction to bring the gear back on center. DO NOT turn the sleeves an unequal number of
turns or turn them in opposite directions because that will disturb the toe-in of the front wheels.
With the wheels straight ahead and the gear on center, check the steering wheel alignment. The 6 o'clock
spoke measured at the steering wheel rim should be within 1 inch of being exactly at the bottom. If the wheel
is not in alignment, remove it and reindex the hub on the steering column splines to center the wheel.
Pitman Shaft Adjustment
Now, with the steering gear on center, loosen the pitman shaft locknut and carefully tighten the screw
(clockwise), until it is snug but not tight. Retighten the locknut to 25 foot-lbs. Drive the car and check for
lash, check for stickiness over center, and for slow speed and moderate speed returnability.
I would suggest the following type road test:
Drive the car and make ninety degree right and left hand turns at about 12 to 15 mph. It helps to do this on
an actual street corner so you can assess how well the steering wheel returns.
Drive the car straight ahead at about 45 mph. Just make small inputs to the steering wheel, (you don't even
need to change lanes). The steering wheel should return to center.
Please note, very small adjustments of the pitman shaft lash adjuster screw can make a very big differences
in gear mesh loads. You should always complete your screw adjustment in the clockwise direction. If you go
too far, make note of the screw location, turn the screw counterclockwise and begin tightening in the
clockwise direction and tightening the jam nut.
Final Road Test
After making the above adjustments your steering should be crisp with very little lash. If there is still some
3/4
lash it may be necessary to go through this procedure a second time, starting with the worm shaft adjustment
and then the pitman shaft adjustment.
A Quick Recap
Don't forget that you adjust the worm bearing first. Position the gear about one-half turn back from full lock
for this procedure.
Adjust the pitman shaft second. This adjustment is done with the gear exactly on center.
Don't overfill with grease.
http://www.corvetteactioncenter.com/kb/questions/59/
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