Steering won't return.....

[Hedgehopper]

My Griffith 500 has been running well and with no problems particularly in the steering department.

I then decided to replace the manual steering rack with a newly reconditioned power rack.

Nothing was changed or altered in any way except for a new longer lower column, new u/js, new pump, hoses and of course the rack itself. The new pump has been replaced but with no effect.

The problem now (and my local indie says it's too dangerous to drive), is that when exiting a bend and relieving pressure on the wheel the car continues to turn at the same rate. The steering only returns if you actually move the wheel...very,very scary! It feels as if assistance is still being applied.

Steering wheel return, as far as I know, is created by the castor angle and this in turn is created by the 8mm spacer in front of the top ball joint. This has not been touched since it was in manual rack mode.

Any advice will be most appreciated.

[mk2 24v]

Any idea what the rack is from? As some of them have an adjustment on the pinion part that if too tight, will cause the problem you are encountering

Other than that, I'd guess the rack itself hasn't been refurbished properly

[PaulKemp]

Have you checked toe?
At IVA we have been known to add a bit of toe out to assist the self centre test.
It's not ideal and only used to pass test before geometry is properly set

[Hedgehopper]

Thanks for the replies.

The rack is standard TVR and has been refurbished by the well thought of (in TVR circles) Kiley Clinton.

Toe-in is the correct 2.2mm and castor is also as standard.

All u/js are new as are the top ball joints and track rod ends.

Jacked up the steering can be moved by pulling and pushing the wheels, with or without the engine running.

Getting very frustrated missing all this top down weather!

[oakdale]

Have you used some of these with the power rack?

http://www.racetechdirect.co.uk/tvr-car-part-h0749...

[The Wookie]

My first port of call would be to check that the UJ's are properly phased as that can have some funky effects like cogging and sticking and the mistake is easily made.

Next port of call would be to jack the front wheels up and give the wheel a twirl to see if there's a lot of friction, as this would indicate something binding up like where the column goes through the bulkhead (there may be a bearing there that's been disturbed by the work), the rack itself (which may have adjustment) or perhaps even the ball joints. If you're struggling to track it down then just progressively remove or disconnect components to narrow it down.

If the steering moves freely with the wheels in the air then it's likely a fault in the hydraulic system, like a missing, broken or faulty torsion spring, and the kit needs to go back.

[Hedgehopper]

Oakdale, thanks. Where does this spacer go? The only one I'm using goes in front of the top ball joint to create castor.

The Wookie, thanks. U/js can't be wrong as there are machined flats across the splines on the shaft for the pinch bolts to locate in. I suspect that you are correct when you mention the rack. Has now gone back to Kiley Clinton.

[oakdale]

Hedgehopper said:

Oakdale, thanks. Where does this spacer go? The only one I'm using goes in front of the top ball joint to create castor.

The Wookie, thanks. U/js can't be wrong as there are machined flats across the splines on the shaft for the pinch bolts to locate in. I suspect that you are correct when you mention the rack. Has now gone back to Kiley Clinton.

I don't know much about TVRs at all but I do know a bit about power racks, so I googled to see a picture of the rack so I would know what type it is before I made any comment.

The first thing that came up was these spacers which are listed as standard equipment for power steering models, so I assume they need to be fitted when a power rack is used.

eta, I guess they fit on the rack mounting points?

Edited by oakdale on Friday 2nd August 22:14

[Matt Seabrook]

Not done much work on TVR's but do the power rack TVR's have the same geo settings as the non power rack setup? Most cars that have manual and PAS on the same model have greater caster on the PAS model. If so have you set the car up to PAS or manual settings?

[Hedgehopper]

Matt, I understand that the geo. settings are the same for manual or power racks. On a TVR Griffith the castor angle is created by a spacer next to the top ball joint thus pushing the top of the front upright rearwards. There is no room to squeeze in a fatter spacer unfortunately.

[Matt Seabrook]

Ok if the top ball joint is back as far as it will go it's unlikely to be that then. Thought it would be worth a shout though. It's not looking good for the rack then.

[finlo]

I had something similar years ago (though not on a TVR) and it was because the rack was'nt centred when the wheels were pointed straight ahead HTH.

[finlo]

I had something similar years ago (though not on a TVR) and it was because the rack was'nt centred when the wheels were pointed straight ahead HTH.

[stevieturbo]

Hedgehopper said:

Nothing was changed or altered in any way except for a new longer lower column, new u/js, new pump, hoses and of course the rack itself. The new pump has been replaced but with no effect.

So everything was changed completely lol.

Most likely port of call are the UJ's

Jack the front up and make sure all joints etc are free to move and rotate.
Nothing sticking at all.
That includes the column itself, the rack, track rod ends, balljoints. If need be unbolt parts so you are testing them on their own.

[fatjon]

Had this with my Cerbera. it was the UJ on the steering not phased correctly. Was certainly an "interesting" drive till I figured it out. What confused me was that it was like that with the old UJs before I changed them as they were partially seized and just the same with the new ones as I phased them wrong which confused me for a while.

[Hedgehopper]

Thanks fatjon. Several people have mentioned incorrect phasing of the u/js and I can see that this might cause a problem.

The Griff. has an intermediate shaft between the lower end of the column and the rack pinion with u/js connecting the assembly together. Each end of the intermediate shaft is splined and has a flat ground across the spline to accommodate the pinch bolts. As the hole for the pinch bolt has to line up with the flat across the spline as far as I can see it is impossible to fit the u/j incorrectly.

Before everything was tightened up the rack was centred and the steering wheel aligned and then of course the wheels tracked (three times now!).

I'm beginning to suspect the rack in spite of it having just been re-furbished.

[Mr2Mike]

Very likely the rack, I have had several reconditioned racks on a variety of cars that have been very tight. This is usually down to a worn rack and pinion not being replaced, but the pre-load just wound up in an attempt to remove any play.

[Hedgehopper]

Thanks Mike, I'm cutting my losses and putting the original manual rack back.