The Steering Saga AKA Lessons to be Learned by Others . . .

[Roadkill]

I'll add this to the Camaro thread but thought this was worth a separate thread as it highlights the ups and (in this case) downs of customising and building a car on a relatively tight budget.

It'll be a epic post for me so bare with me . . .

The Background

I made the decision to change the power steering (PS) to manual steering (MS) on the Z28 a good few years ago.
My main attraction to it was significantly less clutter in the engine bay and also the weight reduction.
The only known downsides were supposedly heavy steering and increased "lock-to-lock" (L2L) turning.  The stock box is just under 3 turns, L2L and the Pinto rack I was looking at was 3.75 turns, L2L so I wasn't too bothered as the increase was small.  I'd also had various MS cars and managed fine so the MS route seemed a no-brainer . . . .

The Kit (Flaming River Pinto Rack, UJ's and Spohn Brackets, clamp and Bump-steer adjusters)

I'd already spent $$$$ with Spohn (pronounced Sphone, BTW) and their Pinto kit came with "everything" you need to fit it to my Spohn K-Member.
Simple !

The Fitting

The kit came with no instructions, no drawing and no reference-points as to where the weld-on brackets actually went.  I had to study pictures on their website taken from multiple angles to position it . . . . even then it just didn't match so I had to trim one of the plates down to achieve what I saw on the website . . . .
The brackets were flimsy.  REALLY flimsy.  I wasn't convinced they'd take the stress and on the first test they failed with no surprises.
The other issue was the connection to the steering column.  The kit came with a piece of 3/4" DD shaft that replaced the intermediate steering shaft (the bit in the engine bay).  This simply slipped into the base of the initial column (the bit inside the car).
Problem is the initial column doesn't run 100% "true" when rotating - it doesn't need to as there is a limited UJ between the initial and intermediate shafts and then a rag-joint before the original PS steering box to work-out any minor indifference's . . .

The solid DD shaft was a fairly loose fit and sloppy from the start so I knew I was in for more issues.

The final issue arose when the 2 shafts and single UJ supplied in the kit simply wouldn't reach the newly fitted MS rack/box.  I tried 7 different variations but I couldn't route it without creating angle too acute which made the UJ bind.

The list of corrections attempted . . .  

First up was the fitting of the rack itself.  I designed and had made a much heavier duty cradle and bracket assembly to neatly and firmly attach the rack to.  Installation went to plan the the rack fitted nicely and more centrally then before.  As a bonus it looked a damn-sight cooler than the Spohn offering.

Note at this point, and seeing no mileage and no actual use, the bellows on the Flaming River MS rack had utterly degraded and fallen apart !

This part of the saga had taken well over a year to sort at this stage . . . given that there'd been two winters, a re-location and various delays for designing and fabricating stuff . . .

So, rack mounted, attention was now on routing the column.
I quickly came to the conclusion that another UJ was needed to achieve the angles required in the routing for the UJ's to operate.

Note that no technical information was offered on the Flaming River website regarding minimum angles / bind points on their UJ's but I determined 135* or less would cause binding (this is quite shallow).

I acquired another UJ and proceeded to start another wave of attempts to achieve the smoothest routing possible.  
Problem with introducing a third UJ, though, was that there was now a section in the middle that wanted to twist about its connections rather than rotate.
This was resolved by adding a Heim to prevent twisting . . this was a ball-ache in itself as there isn't many places to fit such a support to take such stress as will be imposed by the operation of a MS set-up.
But, that said I had a plate made and got the Heim welded to it and it connected to the D/S engine mount bracket.

This whole process took nearly another year to just a couple of months ago.

With the column good it was connected as-per the Spohn website to the initial steering column.  The sloppy connection was crap.  When turning the steering wheel it was notchy.  As the end of the Initial column wasn't "true" as it rotated it made small secondary orbits which wouldn't have been a problem with a stock set-up but transferred down a solid, unforgiving hard shaft felt awful.

So out came the main column and I took it to a machine shop to see if they could make up a new shaft to go from the last UJ to the base of the stock column.  The connection HAD to be the same, but by machining it to suit I'd hoped that the "Orbit" could be reduced.

Unfortunately, this company went bust 2 days later and it took weeks to get it back (without the work completed).  As a favour, the guy I dealt with got the work done for me elsewhere.

The new shaft was a precision fit in the base of the stock column - a true work of art . . . and the "orbit" was massively reduced . . . but still present.

My thinking at this point was that it was probably 3 to 4 times improved on the shaft supplied by Spohn so I should be O.K . . .

So now it's all fitted and, if I'm honest, working as good as it ever, ever could be . . . . But . . . .

The Test drive (last night)

A very short drive, just off the driveway and up the road to a dead-end, turn around and back again.

My observations and opinions . . .

Tightness.  Very good, excellent in fact.  I struggle to believe the odd bits of plate Spohn supplied could ever do what my design did and I can't believe it would ever feel as tight as my arrangement felt.

Response.  Good.  No slack in the box/rack but more on the mechanism in a bit . . .

Ease of operation.  Shocking !  I was amazed at how easy it was to turn the wheels.  Even at speeds below 5mph.  You could just about park the car with one hand on the steering wheel if you wanted so no issues, there.

Turning.  Pretty good.  I knew that extra turn and a bit lock-to-lock may be an issue but it really wasn't.  The other common trick is to fit a C10 MS box  which needs SEVEN turns lock-to-lock !!  I was genuinely very happy with the Pinto's 3.75.

Turning Circle.  Crap.  This is what Spohn, being Third-Gen Camaro specialists should've made clear.  The physical "throw" on the front spindles were about 60% of that on a stock set-up.  This meant that reversing and turning onto the road outside my house needed what amounted to a 3-point turn to navigate the road out of the cul-de-sac !!  As an "all-out" drag car this is fine but utter sh!t for a street car.

Feel.  Poor.  I could put up with the massively increased turning circle alone, but the steering is notchy as hell because of the connection between the stock column and the new set-up.

Conclusion.

I'm not happy.  As I said above, I could handle the reduced turning if it wasn't for the notchy operation.

Possible improvements . . .

There's two ways I see of improving the current set-up :

i) Add a UJ in place of the hard connection between old and new . . . this in-turn would need at least another Heim to support it all and I don't see an easy mounting point for one unless I start putting in hefty bridging plates between the D/S front fender and fire wall (which may or may not work and would look awful).  At that point I think there'd be too much slop in the mechanism to easily control, anyway.  This would take time, loads of effort, designing, fabricating for probably no gain.

ii) Replace the stock column inside the car and the first part of the kit shaft (thus removing the connection in question) with a custom-made single-piece steering column (basically a metal rod).  This would need minimal outlay, would be a fairly simple fix . . . but would need about a day of re-wiring all the switches that connect though the stock column.

But I'm utterly, utterly dead against this (the only real option).

I had a vision for the Camaro when I started, yes it's evolved along the way but I always wanted to keep the interior as stock looking as possible (that's why I fitted a new molded carpet, kept all the interior plastics and sorted the headlining) . . in fact my stipulation was to always keep the stock steering column and steering wheel (unfortunately I had to change the steering wheel as the original had degraded, was falling apart and would've seriously hindered getting out of the car with the bucket seats in the event of an accident.  

So . . .

I've come to the end of the MS path and am not happy.

The original benefits of Manual Steering were weight reduction and less clutter in the engine bay . . . .
Ironically, after all the necessary upgrades, stiffening and improvements I've had to make I'm probably not that much lighter than the stock PS set-up anymore !!!
And as for clutter ?  At the moment it looks O.K but If I start mounting more Heims and UJ's to try and correct the notchy steering it'll re-clutter the engine bay and generally look sh!t !

So I have Manual steering with no real benefits anymore and I'm not happy.

The obviously path to take from here is to take it as a harsh lesson learned and go back to Power Steering.

On saying that, I'm not sure what lesson(s) there are to be learned.  I suppose I felt it wasn't right the day Ian and I went out to start fitting the Spohn bracketry about two years ago . . . I could've made my U-turn, then but how the hell was I supposed to know what was coming !!??

Take from it what you will.  This is a battle I could've eventually won and got working but it would've meant making changes to my original vision too much and I'm not prepared to do it.

I suppose also, I put too much faith in Spohn and not enough in myself.  Just because it's there on the shelf to buy it does NOT mean you can't do it yourself better than they can !

. . . . . . . .

[Roadkill]

If I had to guess-imate . . . I'd probably say that this experiment has cost me around £1100 so far and will cost another £550 to put back to power steering (there's some bits I could sell so would expect £200 back if I'm lucky) . . .
All that said the money isn't what bothers me.  Sure it's a f*cker to think about it but the thing that stings is the time lost.  Mainly my time but also plenty of Ian's time and all the time and effort put in by others along the way too.

The money I can always earn (and spend) again but the time I won't get back.



Amen.

[art b]

i feel your pain..

it always looked like a major mission....

mind you.. so was the exhaust and you sorted that...

[ianjpage]

Very good detailed post, indeed has been a long, often fraught mission to sort the steering out - as you say - tis a shame that it isn't working right and that it taken so much time to get to this stage...

Hopefully though the PS be a fairly quick install and means that the car is then driveable for it's MOT!

Quoting: art b

it always looked like a major mission....

mind you.. so was the exhaust and you sorted that...

Exhaust was, in comparison, nothing compared to the steering!!!!

[Jamieg285]

Have you considered swapping the interior column for another stock one, just in case your's has an odd problem?  

A relatively quick and cheap thing to try before you start making more wholesale changes?

Also, I'm not 100% on my facts, but is there some sort of bearing at the bottom of the main column? Perhaps it needs to be replaced?

[Roadkill]

Quoting: Jamieg285

Have you considered swapping the interior column for another stock one, just in case your's has an odd problem?

Yes.  But I don't have an easily accessible "spare" column.

Plus I'm not convinced that this issue is isolated . . . It may be better in other columns but not perfect as when GM made them their design mean't it didn't have to be perfect.

Quoting: Jamieg285

Also, I'm not 100% on my facts, but is there some sort of bearing at the bottom of the main column? Perhaps it needs to be replaced?

There is a bearing, yes.

But.

On testing the main shaft runs true . . . see below . . .

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The main column (circular rod) runs on the bearing, retained behind a nylon bushing and a pressed retaining ring.  All good up to here.

At the very end the shaft is a pressing (probably a male "die" is inserted and then the tubular end is crushed over it) to give it the oval-ish shape.

On GM's design, the intermediate shaft had a tubular end that slipped OVER this end and a bolt located and held them together . . there was a limited UJ right at this point which would take up any slack or indifferences in the pressed end.

The Spohn design calls for a 3/4" DD shaft to slide INSIDE this end with NO UJ so any indifferences are actually AMPLIFIED the longer the shaft is.

In real terms it meant that instead of being true (ie. rotating on a exact point) the centre point once you'd inserted the new shaft was actually about 9mm in diameter !!!

Quite massive, really.

[Jamieg285]

Quoting: Roadkill

Yes. But I don't have an easily accessible "spare" column.

I know someone that does


I know I'm adding more complication here, but can't you swap the top joint for an original (re-conditioned) GM top joint and link that to the Spohn shaft, with or without some or all of the original intermediate shaft?

For thought further down the line, but you can improve the overall steering lock by moving the tie rods closer to the rotation plane on the upright.  Not sure if I've explained that clearly enough.

[Roadkill]

Quoting: Jamieg285

I know I'm adding more complication here, but can't you swap the top joint for an original (re-conditioned) GM top joint and link that to the Spohn shaft, with or without some or all of the original intermediate shaft?

Tried that - It was one of the 20+ different set-ups I tried . . . that extra joint just adds too much slop, unfortunately.

Quoting: Jamieg285

For thought further down the line, but you can improve the overall steering lock by moving the tie rods closer to the rotation plane on the upright. Not sure if I've explained that clearly enough.

It had occurred to me . . . But that'd mean drilling and tapering work on the spindles (beyond me) plus would increase the effective load on the steering rack . . . . . The rack is advertised for sub 3000lb cars . . . if you shorten the throw the moment changes and will massively increase the load.
As I'm not "a million miles" off of 3000lbs and have 235's on the front I figure it'd be just too much ??

EDIT - Thinking about it, she's probably 3000+lbs !!!

Quoting: Jamieg285

I know someone that does

Would be worth a quick test . . . I wouldn't even need to take it away as the issue is visible without test equipment.