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MG MGB Technical - Castor correction kit

I am thinking of fitting a Costello Caster Correction Kit to lighten up the steering effort of my 1972 MGBGT(as I get this pain in the ear when the wife drives the car). Has anyone had any dealings with this kit or any thoughts about it.

Thanks Paul.
P.W Elmes

Hi Paul. I have used this kit on a customers car and it does help to some extent. The one thing that concerned me was that it does not allow the bottom nut to be tightened up solid.. I made up two small tubes to the thickness of the shim to extend the shouldered part of the stud so that even though I could not get a full nut on the stud and so "lost" the self locking ring at least it tightened up solid against the tube . Jim
j soutar

Paul,

Have a look at this:

http://www.v8register.net/subpages/RV8NOTE232.htm

Tore
Tore

Thanks to you both of you. I wil now look into it further.
Paul.
P.W Elmes

Whilst (as I understand it) a castor angle modification can make the steering lighter when underway, at the expense of less self-centring action after a corner, it does nothing for the weight of the steering when stationary i.e. during parking. I've not driven a car with them but roller-bearing king-pin assemblies are supposed to help with this.
Paul Hunt 2

I've tried the demonstrator and couldn't tell the difference. But the clutch was gone, so I might have been concentrating on preserving that!

My concern remains that, without some kind of angled washers, tightening the nuts is putting a bending moment into the studs. Might be fine of course, but then again it might not be! And the studs are not long enough to take care of the shim AND an angled washer.

How about a bigger steering wheel? Or a bigger wife?? :-)

Neil
Neil22

The reduction of caster should help the steering effort when parking, as the effect of caster is to lift the front of the vehicle a fraction as the wheel is turned from the straight ahead. The actual weight of the vehicle provides much of the self centering affect. Modern tyres require a lot less help. I myself have not tried the caster reduction and it would seem from the experience of others not make a great difference, however I will give it a go in the future as I can see no down side.
Denis
DENIS4

"a bigger wife"

Now that *would* be asking for trouble!

"The actual weight of the vehicle provides much of the self centering affect"

All of it, in fact, as if there were no weight on the tyres there would be no self-centering.

"Modern tyres require a lot less help"

Depends on how 'modern' you are! I started driving with cross-plies, radials are much harder to turn, but that is down to better grip between tyre and road, which itself is due to the larger contact patch for a given size of tyre. When I eventually fitted radials to the front the first corner I took I nearly went up the kerb due to the almost total lack of understeer compared to cross-ply.
Paul Hunt 2

Hi.Neil.I wonder if you could give me the steering wheel to wife ratio.On the serious side B&G supply a kit, Would be good to hear their view. thanks to all for your comments.

Paul
P.W Elmes

Paul,

I fitted the B&G kit and it has definitely reduced the steering effort, I have 195/65 x 15" tyres so the steering was very heavy and loaded up significantly in tight corners and roundabouts, the B&G kit has reduced the steering effort to acceptable levels and made the car much more drivable.

For tech info see link above in Tore's post.

Kevin.


Kevin Jackson

Paul-
I installed the Brown & Gammons kit on my MGB and was immediately impressed with the reduction of steering effort. It was necessary in my case due to the fact that I had installed a Quick Rack for fast driving on mountain roads.

The Castor Angle reduction kit (Brown &Gammons Part # AHH6195 CASTOR) is produced for both Chrome Bumper and Rubber Bumper MGB and MGBGTV8 models by Brown & Gammons, the mg specialists at Baldock in the UK. It is designed to accomplish two things - first, to reduce the Castor Angle by 3 from the original 7 to 4 and, second, to maintain the integrity of the mounting of the crossmember to the leg of the chassis. It is worthwhile to understand how this new kit achieves this goal with well thought out, thorough engineering details that ensure that the mounting bolts continue to be positively located in the taper seats of the chassis legs, and that the rubber mounting pads are not crushed, in order to achieve an accurate Castor Angle setting. This is an improvement over another kit currently available, which when fitted results in the taper of the bolt being held away from its seating and the rubber pad being crushed when the assembly is torqued down.

In the Original Equipment design, the crossmember mounted to the chassis leg in an orthodox manner. The MGB front cross member is fabricated out of pressed and welded steel sheet and is mounted on the underside of the chassis legs (which are box sections extending forwards from the monocoque body) with four high tensile steel mounting bolts which are positively located into the chassis leg on tapered seats. On either side that the topmost part is a platform with four holes on which the lever arm shock absorbers are mounted. Just inboard of those platforms are the two large holes through which the crossmember is bolted on either side to the chassis legs by the mounting bolts. The Front crossmember is fabricated out of pressed and welded steel sheet and is mounted on the underside of the chassis legs (which are box sections extending forwards from the monocoque) with four high tensile steel mounting bolts which are positively located on taper seats into the chassis leg. The mounting bolts have screw threads at both their tops and their bottoms and a thicker plain shank in the middle, with a taper at the top. The intention of the design is that the taper locates to a corresponding taper seating in the bottom of the chassis leg. Hence, the mounting bolt is positively located in the center of the hole in the chassis leg when it is bolted on with a torque of 56 Ft-lbs. This leaves the bottom part of the mounting bolt protruding below the chassis leg with a plain section, and beneath that a narrower threaded section forming a shoulder at the end of its plain shank. A rubber pad that acts as a packing piece between the chassis leg and the mount on top of the fabricated crossmember is fitted over the plain shank of the bolt. This is held up by a rectangular washer with a smaller diameter hole so that the washer sits on the shoulder of the plain section of the mounting bolt but is held in place by the bottom locking nut. The pressure on the rubber pad between the chassis leg and the crossmember is therefore limited so that crushing is avoided.

How does the kit reduce the Castor Angle? The method used is to simply rotate the crossmember towards the front of the vehicle by placing a precisely-machined stainless steel packing piece between the front crossmember mounting points and the underside of the chassis leg. Since the steel packing has used some of the length of the plain shank of the mounting bolt, a steel collar that has to be installed is supplied with the kit. Its effect is to extend the plain shank of the mounting bolt back to its original length. Without this collar, the rubber mounting pads would be overly compressed, thereby ruining both the mounts and the ride quality - and of course the crushing would give rise to variances in the Castor Angle, even between each side of the vehicle. New slightly shallower high tensile steel locking nuts are provided in the kit in order to fit the reduction in useable thread length of the mounting bolts.

Because the angle of the crossmember brackets upon which the steering rack is mounted will have changed slightly (3) in relation to the chassis legs, the body of the pinion shaft of the steering rack will no longer properly align with the universal joint of the steering column. The steering rack brackets will therefore have to be packed at the front in order to realign the rack with the universal joint. Six packing shims are included in the kit for this purpose. Brown & Gammons estimate that installation of the Castor Angle reduction kit requires approximately three hours work. The kit includes comprehensive fitting instructions and detailed diagrams.

While you are working in this area on installing the Castor Angle reduction kit, it is well worth checking the condition of the steering rack brackets for any hairline cracks or more serious fractures. Should you encounter such problems, a Steering Rack Mount Strengthening Gusset is also available from Brown & Gammons (Brown & Gammons Part # AHH6195 BRACKET).
Steve S.

Steve, many thanks for that superb explanation. I have my crossmember off the car at present and have been wondering about a castor-reduction kit, but didn't like the wedges that are commonly advertised. Your thorough description means that I will feel quite confident in ordering the B&G kit. Thanks again.
Mike Howlett

This thread was discussed between 11/11/2007 and 15/11/2007

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