Heavy steering on my Hunter

[gouldsborough7]

While brain is in gear, has anybody experience of heavy steering problems? Having been used to reasonable steering on my Berli except when parking, I am surprised that my Hunter is quite heavy to haul around, particularly on tight bends.

Terry @ Marlin told me to use 18 psi in the tyres all around, whereas the previous owner used 25 psi. Tried both, but no real difference. Tyre & steering wheel sizes are not much different. Don't think the tracking is out, as the tyres have worn quite evenly.

On full lock, the inside wheel of the turn is leaning over. Presumed to be in the design? Very strange in my experience.

Although 11 years old, the car has done only 9,000 miles. Perhaps steering ball-joints are dry, needs grease or what? Haven't jacked up the front yet to check it all out.

Your thoughts would be appreciated.
Cheers
Mike

[dogoncrazy]

Re: Heavy steering on my Hunter

Mike Have you tried jacking up the front end and trying it? it will obviously be lighter due to no tyre contact but if still excessively stiff then you may be able to pinpoint the problem .No greasing is possible and the bottom ball joint is part of the track control arm, upper is from a Metro i think.

[dave_kitson]

Re: Heavy steering on my Hunter

The build manual says 22psi all round. There are no grease nipples, but new ball joints are cheap enough if they seem stiff. They are from a Metro.
Dave

[djj_engineer]

Re: Heavy steering on my Hunter

Hi Mike
If you do jack it up, it may be the rack that is tight. Again I don't think there is any provision to lubricate the rack, apart from dismantling it!
They are not the lightest car to drive at low speed or parking but should not be heavy when they are moving

[gouldsborough7]

Re: Heavy steering on my Hunter

Guys
I haven't tried the steering on jacks - will do over the weekend. I'll also pump the tyres to 22 psi, although I don't expect much change there, as they were originally on 25psi.

Have just driven to work to establish when the steering is at its heaviest (and also for fun!). Roundabouts, 90 degree junctions and tight bends all need seriously extra muscle. I am sure that the same situations in my old Berli required far less effort, and it was fitted with bigger tyres.

Any comments on the inside tyre on a tight turn leaning over? Is this normal for a Hunter?

Cheers
Mike

[Cabrio_Simon]

Re: Heavy steering on my Hunter

Hi Mike,

The steering on my Cabrio was quite heavy when taking tight bends but improved dramatically when I reduced the castor angle. It was initially very high (12 degrees!) but is now adjusted to 4.5 degrees which has lightened the steering loads considerably.

I've used 'compression struts' on my front suspension in place of the Sierra anti-roll bar, which allows the caster angle to be easily adjusted (any may explain why the steering on my car was so heavy initially!):

http://www.flickr.com/photos/marlin_bmw_cabrio/2639342969/in/set-72157605993210128/

If your castor angle is too high you might be able to achieve some adjustment by playing with the shims on the top wishbone.

Hope you get it sorted!

Simon

[gouldsborough7]

Re: Heavy steering on my Hunter

Hi Simon
Like your pics! You've really put a lot of effort/cash into getting your Cabrio to a high standard.

Years ago on my Robin Hood kit, I replaced the Sierra anti-roll bar with something like the struts in your photos, except they were home-made by another club member, and not so sophisticated-looking.

My previous Marlin was a Berlinetta, but that had Cortina suspension and never caused any problem with heavy steering, except at parking speed.

By the way, when yours is on full lock, does the inside wheel of the turn lean over? This strikes me as very strange, and is difficult to straighten once the turn is completed.

Your 'castor angle'info looks to be the likely answer to my problem. Could you advise where you bought the 'compression struts' and then how to do the fitting & setup?
Thanks
Mike

[dave_kitson]

Re: Heavy steering on my Hunter

Hi
The front wheels really want to be pretty near vertical. Check with a plumbline from the front wing, and measure the distance from it to the top and bottom wheel rim edges.

Shims can be easily made from galvanised sheet steel, and fitted under the top wishbone mounts. Worth trying before going to the expense of compression struts. If you make the shims as a flat plate with 2 slots in, you can slide them in without competely dismantling the wishbones. Also add a 90 deg bend at the front so you can lever them out with a screwdriver if you put in too many.

I've not encountered any cars where the bottom of the wheel needed pushing out, and that would be more difficult to fix. Finally recheck the tracking which should be as per Sierra.
Regards - Dave

[gouldsborough7]

Re: Heavy steering on my Hunter

Thanks Guys
I've also been in contact with the factory, as on the original build they would have worked to a specification, which didn't come with the car in the form of build manual.

Mark's reply concentrated on checking all moving parts for adequate lubrication. I've asked them for a datasheet, so that I can do geometry checks (or get someone else to do them!).

I assume that the steering was fairly light when the car was assembled by Marlin, because it was built for a woman. Not being sexist, and don't know whether she was large/small or young/old, but as she paid a huge bill in 1998 (I've got the invoices) I assume she wouldn't have accepted the heavy steering as it is now. So I must assume that the geometry was originally OK - can it change in only 9,000 miles of use?

So as an easy-to-do first stage, I'll check the wheels for being vertical with a plumbline as you suggested Dave. Second, it would be fairly easy to do a certain amount of dismantling, and check all joints and other moving parts are operating well.

If nothing is resolved at this point, I will then have to get more serious with the geometry.

Cheers
Mike

[dogoncrazy]

Re: Heavy steering on my Hunter

Hi Mike
Is your 'Hunter' the same vehicle that appears under reg no S20 HF on the forums car section? If so I viewed the same vehicle at Marlins premises about 5 years ago -it was for sale at close on £9000 then

[gouldsborough7]

Re: Heavy steering on my Hunter

Guys
Looking at the wishbones or whatever, I cannot see anywhere that shims can be fitted. The mounting points are part of the chassis, i.e. welded on, so shims don't seem to be an option to pack under something, Dave. Correct me if I'm totally wrong - see pics attached.

I did a quick check of the camber, and the car appears to be set up with Negative camber i.e. the top of each front wheel is nearer the engine than the bottom, by about 12mm. I'll do a more thorough check when I get a new plumbline.

I haven't checked the tracking yet. I guess zero toe-in might be a good start. Anybody got any positive figures for this?

Alan, I've attached a pic of my car for your interest. The Reg No. is S772NNV

I suspect changing the Castor Angle would be the way forward, or else power steering could be a good idea, but I expect it will cost an arm/leg, assuming there is space for the pump. Perhaps an electric version per Vauxhall Corsa could be made to work?

Cheers
Mike

[gouldsborough7]

Re: Heavy steering on my Hunter

Oops!! Pics were too big for system. 2nd attempt now compressed.

Mike

[dave_kitson]

Re: Heavy steering on my Hunter

Hi again
Can't see any pics of any size.....!

That sounds like rather a lot of -ve camber. A bit is ok for hurling it round a track, but I'd try reducing that. The toe-in should be about 2mm, but you will need to get it done at your local tyre place anyway, and they'll have the figure for the Sierra. Best done after the other adjustments.

You can make a plumbline with a length of light string and any sort of weight, just to pull the string straight and vertical. Make sure the car is on the level!

The top (fabricated) wishbones pivot on M10 bolts in rubber bobbins, which are mounted in U-shaped brackets. These are attached to the chassis with captive M8 studs. If you slacken the M8 nuts you can slip shims between the bracket and the chassis (use the same fore and aft). That is unless your chassis is different to the norm, there were often detail differences from one car to the next. The only difficulty is getting a spanner on the M8 nuts - it is worth investing in a good flexible 13mm ratchet spanner, I got one from Halfords without spending too much.

Oh, the inside wheel does lean a fair amount on all the Cabrios I've seen. Hope that helps - Dave

[gouldsborough7]

Re: Heavy steering on my Hunter

Dave
I think I have sussed out a way of reducing the photo size to below 200k, so hopefully a pic will appear to show the suspension. Does this layout match what you are saying? Can I shim out the top wishbones as you suggest?

Alan
Have only just realised that my car used to be S20HF. A photo is below (hopefully). I just didn't spot the difference in the paperwork until last night. The previous owner's initials were HF, and she must have done a swap of Reg Nos when she changed cars - to a Jaguar I believe!

My Hunter had been SORN'd a couple of times, so it could have been for sale in one of these periods. I think I've got paperwork to show that the car went back to Marlin once for new adjustable front shockers. However, the lady in question lived at Milton Keynes - a long way from Devon. So, did she get fed up and try to sell it through Marlin? In all, she owned it 11 years. I could ask her for a potted history I suppose.


Cheers
Mike

[Cabrio_Simon]

Re: Heavy steering on my Hunter

Hi Mike,

Your setup looks to be the same and it should be possible to shim the top wishbone away from the chassis by loosening the nuts that hold the U shape brackets to the chassis rails (the nuts are behind the U brackets and not that easy to access..). Adding the same width shims to the front and back will adjust just the camber whilst there is some scope to adjust the castor by adding
shims to either just the front or back.

The compression struts came from below:

http://www.compbrake.co.uk/COMPRESSION_STRUTS.HTM

Adjusting the castor with the compression struts is much simpler ! The fitting is very straight forward and they replace the Ford anti-roll bar (which isn't really needed on the Cabrio with its very low centre of gravity). The anti roll bar is bolted to the chassis at 4 points and to the lower arms with 2 large nuts. The compression struts use exactly the same attachments and are quite a common fitment on performance Fords.

The wheel alignment can be set up roughly at home (as I did) but I would recommend getting the final alignment done professionally to get the camber / castor and toe settings spot on.

Hope this helps!

Cheers

Simon