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PostPosted: Sat May 22, 2010 10:09 pm 
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Hi all.

The car: 1956 356A with OEM VW steering box.

The symptoms: Vague unweildy steering when straight ahead or just entering exiting a corner. No problems once on lock and actually cornering. Steering wheel feels very stiff to turn. Not keen to self-centre. Car continues to track around gentle corner even when steering wheel released part way around corner. Feels like I have to steer too much at the transition from straight to curve, but having entered the curve I have to 'un-steer' to avoid oversteering. Same on transition from curve to straight. All this at ordinary 30-50mph driving speeds.

Other Relevant Info. 'Run of the mill' aftermarket 15" by 5 1/2" wheels all round with new 165 tyres. 32 lbs pressure all round. Wheel alignment recently done, 2mm toe in at front, all new tie rods and ball joints, link pins, shims in correct places, OEM steering rack reconditioned. I have not had the rear wheel alignment done (yet).

My thoughts I don't think it is due to incorrect offsets or tramlining - these are bog-standard after market 5 1/2" wheels. My tyre pressures are probably too high and I could experiment, but I don't think that explains the stiffness. I'm inclined to think that the steering box has been 'set' a bit too tight, and that I could loosen off the lock nut, undo the screw 1/16 - 1/8th of a turn and try that. But before doing anything I'd thought I'd seek some advice / comments.

Whaddya reckon? :-)

All opinions much appreciated.

Dave
Australia

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Last edited by David Overington on Sun May 23, 2010 9:37 pm, edited 1 time in total.

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PostPosted: Sat May 22, 2010 10:25 pm 
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David Overington wrote:
having entered the curve I have to 'un-steer'

I'm inclined to think that the steering box has been 'set' a bit too tight, and that I could loosen off the lock nut, undo the screw 1/16 - 1/8th of a turn and try that.

Dave
Australia


Yes, and if, after loosening the steering box adjustment, the 'reconditioned' box is too loose in the 'sweet spot' straight ahead and tight in the turns so it needs to be 'unsteered'.... a new VW TRW box/Pitman arm and appropriate tie rod ends will fix you up.

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 Post subject: Hard to Steer
PostPosted: Sun May 23, 2010 12:40 am 
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Many years ago, I had an aftermarket steering wheel in a 356A. I found that when I torqued the securing nut down, it bound the steering wheel and it had the same conditions you mentioned. Confirmed the problem by loosening the nut and driving down the corner and back. Stock wheel solved the problem. I never investigated the tolerance that was out of spec and resulted in the problem, but if all fails and you have an aftemarket wheel, you might explore that possibility.

STP

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Steve Proctor
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PostPosted: Sun May 23, 2010 1:55 am 
You can try to adjust the box, it has an adjuster on its top. I remember that
when VW used this box the top sometimes came loose, check the 4 bolts holding
the top on.

Alan

Steve Proctor wrote:
Quote:
Many years ago, I had an aftermarket steering wheel in a 356A. I found that when I torqued the securing nut down, it bound the steering wheel and it had the same conditions you mentioned. Confirmed the problem by loosening the nut and driving down the corner and back. Stock wheel solved the problem. I never investigated the tolerance that was out of spec and resulted in the problem, but if all fails and you have an aftemarket wheel, you might explore that possibility.

STP

------------------------
Steve Proctor
Registry #1752 (Since 1977)
Car #84757 ('58 Speedster)








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PostPosted: Sun May 23, 2010 2:17 am 
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Hi Gents, thanks for the fast and helpful responses. Much appreciated.

Bruce, just to clarify, two questions:
1) I have new tie rods and tie rod ends (originals only adjustable on one side, these new ones adjustable at both sides). The OEM RHD pitman arm is in excellant condition. Given these points, woould I still need to replace these items if I end up having to get a new VW TRW box? , and
2) Is a 'VW TRW' box different from an OEM VW box - ie better handling etc more like I understand the ZF boxes to be? (not concerned with authenticity, just with steering attributes)

Steve, thanks I've got the original steering wheel but will check to ensure no binding.

Alan, thanks for that suggestion - I'll check that too.

I had better also re-check that I properly tightened the 4-bolt rubber union on the steering shaft!!

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PostPosted: Sun May 23, 2010 6:46 am 
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Joined: Tue Apr 01, 2008 9:34 am
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Location: southeastern PA
David Overington wrote:
Bruce, just to clarify, two questions:
1) I have new tie rods and tie rod ends (originals only adjustable on one side, these new ones adjustable at both sides). The OEM RHD pitman arm is in excellant condition. Given these points, woould I still need to replace these items if I end up having to get a new VW TRW box? , and
2) Is a 'VW TRW' box different from an OEM VW box - ie better handling etc more like I understand the ZF boxes to be? (not concerned with authenticity, just with steering attributes)



The best substitute I've been able to source for the replacement of the OEM early 356 VW steering box lately is a quality unit made by TRW for a VW and it's relatively inexpensive.

The shaft for the Pitman arm has a smaller diameter, so the original cannot be reused. New VW versions are available but do not have the 356 provision for a steering dampner, but a VW version can replace that, also relatively inexpensive. The tapered holes for tie rod ends are also slightly smaller for a VW, so the inners, also inexpensive VW units, can be substituted as well. Installed, the appearance to original is very close, it's safe and NEW.

The steering is fine..... and smooth, and maybe while not quite what a ZF in new condition may be, the cost and ease of fitment works just fine as a replacement on the rather primitive early 356s.

The total of the new parts cost me less than half of what a used ZF unit is bringing and if I ever need to replace the ZF on my '58 T-2 A, I'd have no problem using these parts....but my VW man tells me they are getting scare, too, just like the good OLD original 356 steering parts!

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PostPosted: Sun May 23, 2010 6:52 am 
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Don't forget the shaft/bearing pre-load adjustment at the end of the input shaft!

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PostPosted: Sun May 23, 2010 7:10 am 
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Thanks again Bruce.

And thanks Vic for your comment too. The chap who reconditioned the box knows his stuff so I'm pretty sure all the shiming etc is right. Fingers crossed.

I sure do hope that it is just a matter of adjustment. I've been reading my manual and plan on disconnecting the damper and tie rods from the pitman arm and adjusting the adjusting screw "until a slight resistance is felt when turning the steering wheel through the central position".

I have felt that resistance - quite strong - at certain points when cornering. My manual goes on to say if this resistance is set too high then there is too much slack when turning the wheel more than about 3 degrees from centre. All very consistent with my horrible steering symptoms.

So the more I read and investigate and drive, the more I feel that slackening off the adjuster will go a long way to solving the problem.

Once again thanks and I'll post the results of my adjustments, hopefully in a couple of days.

Cheers

Dave

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PostPosted: Sun May 23, 2010 9:22 am 
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" after loosening the steering box adjustment, the 'reconditioned' box is too loose in the 'sweet spot' straight ahead and tight in the turns so it needs to be 'unsteered"

Bruce,
I had this problem with a ZF box, but maybe the thought still applies. The symptoms were the same, and several experienced mechanics told me I needed a new steering box; it turned out that the Pitman arm was not indexed correctly, and as a consequence it was loosey-goosey in the straight ahead position and tight on one side when in a turn. The steering box adjustment was made in the 'straight ahead' position rather than at the high spot, so it behaved as you say. The way I discovered the problem was by finding that the center-to-lock was not the same in both directions, and that the tie rod ends were adjusted to extremes on both sides to compensate for the misplacement of the Pitman arm. I reset the arm (it was off 2 splines), adjusted the clearance, and it works perfectly now.
I would check first that the center-to-lock is the same in both directions, I didn't catch it when I bought my car.
Gary


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PostPosted: Sun May 23, 2010 2:35 pm 
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Make sure the rebuilt box got filled with lube. Mine acts funny when it all leaks out.

Just a thought.

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PostPosted: Sun May 23, 2010 3:10 pm 
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Thanks for the additional comments all.

Hi Gary, you said "The steering box adjustment was made in the 'straight ahead' position rather than at the high spot" - but isn't the tight spot meant to be straight ahead - my manual states "Turn the adjusting screw until a slight resistance is felt when turning the steering wheel through the central position". My pitman arm is on the correct splines, but I'm almost sure when driving that the excessively tight spot is not straight ahead. If the tight spot is meant to be straight ahead AND if the pitman arm is aligned properly it means I will need to turn the steering shaft to get the re-adjusted 'less-tight' spot straight ahead, refit the steering wheel to get that staight ahead (in relation to the tight spot) and then redo the wheel alignment so that the wheels too are straight ahead in relation to the tight spot. And recheck that the lock is not being inhibited by damper throw and re-adjust if need be. I think that's the logic

Hi David, I filled the box with 90 grade gear oil, so that is OK.

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PostPosted: Sun May 23, 2010 4:04 pm 
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I had a similar problem on the F Vee with steering that would not self centre and was heavier than it should have been. The cause was when I replaced the box with an older style box I did not center it correctly on the beam. In my case because the box is centred on the beam being a single seat car with symmetrical steering it caused the ackerman to be off one way more than the other. Not sure how this would play out in a 356 but worth a check to see if the box is properly aligned on the beam. Do the early cars have a tab welded on to align the steering box?

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PostPosted: Sun May 23, 2010 5:44 pm 
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I sounds like the exact problem I had in an old Pajero, very very heavy in turning, I found out that someone had disconnected the pitman arm straight and re-installed it at full lock.

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 Post subject: horrible steering
PostPosted: Sun May 23, 2010 9:08 pm 
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]you said "The steering box adjustment was made in the 'straight ahead' position rather than at the high spot" - but isn't the tight spot meant to be straight ahead - my manual states "Turn the adjusting screw until a slight resistance is felt when turning the steering wheel through the central position". My pitman arm is on the correct splines, but I'm almost sure when driving that the excessively tight spot is not straight ahead. If the tight spot is meant to be straight ahead AND if the pitman arm is aligned properly it means I will need to turn the steering shaft to get the re-adjusted 'less-tight' spot straight ahead, refit the steering wheel to get that staight ahead (in relation to the tight spot) and then redo the wheel alignment so that the wheels too are straight ahead in relation to the tight spot. And recheck that the lock is not being inhibited by damper throw and re-adjust if need be. I think that's the logic

Hi David,
My comments were about a ZF steering box on my '65, but I'm pretty sure the same techniques apply. You're right in your approach above, that the tight spot (the spot that you adjust for minimum clearance) should be in the straight ahead position; in my case it wasn't and although the FO had adjusted the clearance correctly, it was about 10* to the left of center, and so when going back to straight ahead, or on center, the steering was loose. He aligned the front end at that same straight ahead position also, but when I counted the turns on either side of that position it was something like 2 turns to the left and 1 turn to the right. On my ZF box there is a scribe mark on the input shaft that is coincident with the tight spot, and the turns to the extreme left or right of that mark are equal. One other thing that I had to adjust besides the Pitman arm was the steering damper, as it's travel was slightly less than the travel required for full lock to lock. (a Pelican parts damper, and not a Koni which has more travel); it was clamped to the beam incorrectly and limiting the steering box travel in one direction. So be sure of the Pitman arm index marks, align the front end and steering wheel straight ahead based on the index mark or tight spot, confirming that its rotation is the same from center to extreme left and right, and adjust the steering damper anchor position so that it also allows equal left-right of center steering box travel. Your steering box may have a pin that locates it on the beam, be sure that the steering box is located on it before doing anything else. On my '59A, someone had clamped the steering box down without the pin engaged in the hole - slightly to one side of it, and the pin collapsed the tube so that there was an interference with the suspension arm rotation. That was a whole other source of heartburn. It sounds like you're on the right track.
Gary


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PostPosted: Sun May 23, 2010 9:41 pm 
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FIXED.

I have unwound the machine screw 1 full turn (1/2 a turn was not enough) and the horrible steering is now all fixed. Maybe over time I may tighten it up 1/4 of a turn or so to reduce a bit of slack, but otherwise all is good.

Thank you everyone for your input, very much appreciated.

Dave

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