Hey guys
Ive pretty much finished my big block 70 resto mod. Ive replaced everything in the suspension and steering, including borgenson. My one observation is that I have about 1/2 to 1 inch of slop in the steering wheel before it turns the borgenson. I did replace the rag joint with a u joint but I believe the slop is within the steering column. I did not replace the bushings/ bearing in the column. Is it possible the steering column is the culprit? I can jiggle the steering wheel even when the car is parked.

thanks for any input
*****

 

Interesting idea...I have the same amount of play however it seems to be in the steering box. Never thought about it being in the steering column itself. Curious to see what the experts say.

 

so the column could be wallered out where the collapsing sections slide into each other which is kind of unlikely or if its a telescoping column theres the slop could be where that sliding shaft hardware meets. if its side to side slop then its the bearings in the column.

 

It’s not a tele wheel and there’s no movement side to side. The movement is only when you turn the wheel left to right

 

Can you put it on ramps and take a video? You'll likely need two people to see what you are describing.

The lower steering column bushing is easy to replace (with the column out of the car), and can get wrecked by dropping the column without loosening the horseshoe at the firewall.

 

That sounds like the 1" of slop would either be in the rag joint or the box itself.
The rag joint movement is easy to see with two people.
Box movement is much more difficult because the pitman arm moves so little, at first.

I would not be surprised it is in the box.
A borgeson is just a standard rebuilt box, with an adapter plate welded on to fit our cars.
It is not a blue-printed high performance unit.
For one of those, you will need to have GTR1999, Turn One, or Tom Lee rebuild it to tighter tolerances.
Once you do that, the wheel will have 1/8-1/4" of slop movement.
It can and will feel exactly like a rack-n-pinion unit.
There are two shafts involved, with two different adjustments, and at times the fix involves going far beyond just setting those.
But that would be my first step, to pull the box, and set both adjustments to zero lash with an in-lb torque wrench, on the bench, per the service manual.

On my Tom Lee box, they machined the bearing surfaces true, select fit ball bearings, and IIRC adding a bearing to the one shaft that did not have one.
It was a night-n-day improvements in slop and feel.
It was a Nascar box, built to Nascar specs.

I liked it so much I just had Turn One do the same thing to my C3 Borgeson box last month. They do that now.
They also changed the effort, by swapping out the torsion bar for a stiffer one.
Turning effort increased from a rather limp 28in-lbs to 45in-lbs, almost double.
That is 4 lbs at the wheel rim vs 6.5#.
Most people like the Turn One standard torsion bar of around 32-36 in-lbs, (5#) but I wanted mine even firmer, more like a race car.
I felt my 500HP BB deserved that.

 

Steering box differences:

The OEM C3 manual box uses grease for a lubricant, and has only one bearing inside, there are three highly loaded bronze shaft bushings. So it develops quite a bit of slop after 50 years. Especially because no one ever re-greases them, and the grease gets very dry causing a lot of wear. The majority of the force / pressure is on the pitman shaft, and unfortunately it rides on two bushings, and they are frequently dry.
https://tech.corvettecentral.com/201...ring-concerns/

The original GM Saginaw Delphi 800 style PS, not used on C3s, is slightly better with at least one needle bearing on the pitman shaft, and it uses thin fluid for lubrication. So it tends to wear less. It also uses a needle thrust bearing which is very sensitive to pre-load adjustments.

Both shafts in the above two designs, each have their own pre-load adjustment. Both must have zero play and "drag" in the low inch lb range to have no slop at the wheel. The adjustment procedure is attached. Most people know where to find the one top mounted adjustment screw, but the second one is what causes major amounts of slop. Both need to be correct, and adjusted on the bench.

The Borgeson box "conversion" for our C3s, is a much newer style Delphi 600 box. It has completely newer style internals. The power piston is controlled by a rack-n-pinion style gear, which was originally developed for this box. That control gear was later used in rack-n-pinion steering gears, so it is the same part design, and is much improved over the older Saginaw box. It also uses multiple needle bearings inside on the main shafts, for less internal slop, and has no thrust washer, or second pre-load adjustment. There is only the top "over-centering" adjustment.

The Delphi 600 "Borgeson" box for our cars was built for a Jeep. It has the long pitman shaft our cars require. They weld a bracket on to make ita bolt-on to our cars. It is not a brand new box, it is a rebuilt box. The feel is controlled by the lightweight torsion bar inside. Around 28-30 in-lbs. This is about the steering wheel "heft" or weight of a stock C3 power steering system. However the steering ratio increases from 16:1 to 12.7:1 setup. So it will tend to feel more sensitive.

I strongly recommend using the Manual Steering or outer holes on the C3 steering arms. The overall quickness of the steering will still be faster than even a OEM C3 PS steering setup.

Warning: If you use the inner or PS steering arm holes, you may find the steering entirely too fast for comfort. At that point it will be faster than a C7 or C8 or a Viper, and most any other car on the planet. With the light feedback/feel the entire steering effect often feels uncomfortable to the driver. Especially if you have low caster settings of 1-2*.

Add as much caster as you can in your alignment. Strive for at least 4*, or even more. It really helps with a Borgeson setup especially, even more than a OEM PS car, due to the faster gear ratio inside. If you have added as much caster as you can get, even with new upper a-arms, and 6* caster, and are using the MS holes, and you still feel it is too light and too twitchy for your tastes, that is when I would mail it off to Turn One for a re-valve.

Attached are the two overhaul manual sections that describe how to adjust the lash or pre-load in each style box.


Two Gearbox pre-load adjustments for C3 manual box or early Saginaw PS box



Single pre-load adjustment on Borgeson Delphi 600 box

 

OP I just remembered one other even easier item you may need to check first.
Did you install the box yourself?
The box must be exactly centered. Because there is a high spot on the gear, that's the only point where there is no lash/looseness.
So you center the box first, using the internal stops as a guide, left, then right, then exactly halfway.
Then you install the steering shaft, it has a centering mark also, inside the car, that must match the box.
Then you put the steering wheel on, straight up.
Then you put the tie rods on, and adjust them until the wheel is straight again.

I have one car that suddenly gained that infamous 1-2" of slop, where it had none before, because I just threw some new tire rod ends on it, and I did not get the wheel dead straight at first.
When I re-adjusted the tie rods, and got the wheel was straight again, it went back to the high-spot on the gearbox gear, and I was back to zero slop.

 

I double checked everything and I noticed the excess movement was from the u joint before the borgenson. I checked all the lock nuts on the ujoint and that’s where the play was. I tightened everything properly and the play was 90% gone.
thanks for everyone’s input

 

Easiest Fix!