TC steering

[C. Knight]

B Purcell wrote:

> Has any one out there who has experience of the affect of these wedges > on their car's handling, either done, or had someone do, an actual > measurement of their car's caster angles?

Yes. Our TA started with a "collapsed" chassis giving excessive castor angle of 8+ deg and very heavy steering. I temporarily corrected the fault with wedges. During the rebuild I set up the chassis as per the MG brown book and fitted new springs. Castor measured exactly 6 deg as specified. I can confirm that T-ABCs will only handle correctly with a castor of approx 6 deg. The early TC angle was 2 deg greater than all previous MG Midgets due entirely to the replacement of the TA/B trunion boxes with shackles. The 8 deg angle accentuates overstear and makes the early TC a pig to drive. The 2.5 deg wedges restore this to 5.5 deg which makes the TC theoretically a little more sensitive than the TA. The wedges specified by MG were stock items and the 2.5 deg wedge angle was not optimized for the design error on the early TCs. Traditionally Midgets were designed with 6 deg castor angles so it seems that the early TC was a design error. Castor angle is easy to have measured at the tyre depot or to measure yourself. I posted a simple method some months ago but if anyone needs it again mail me. If you want you car to handle tolerably well then check the castor and set it up to TA or later TC spec with custom made wedges. As Clive says the rest of the geometry also needs to be correct as well. If your chassis is OK, incorrect castor probably means collapsed springs or a bent axle and wedges will only affect a partial improvement to handling. Regards Cliff

[C Sherriff]

Message text written by "C. Knight"

>

B Purcell wrote:

> Has any one out there who has experience of the affect of these

wedges

> on their car's handling, either done, or had someone do, an actual > measurement of their car's caster angles?

================================================ Actually this is the wrong question it should be: " Has any one out there who has experience of the affect of incorrect steering angles and chassis set up etc on their car's handling, either done, or had someone do, an actual measurement of their car's caster angles? " On a number of occasions I have had to "sort" out a T Type and in every case its a matter of overall alignment, setting the springs correctly and straightening and aligning front ( and even rear ) axles. The castor and steering angles do make a significanr difference - sometimes stuffing a wedge in helps mask that, sometimes not. It everything else is right on a TC it helps, on a TA or TB it does not. I have been asked to repost my article on set up that is being printed at present in the Octagon Bulletin and will do so over the weekend. Clive

[B Purcell]

Clive, Thank you, I fully agree (i) wedges aren't the only thing that impact on the T type's steering/handling, and (ii) there are many other components that need to be set correctly for any car (and possibly a T type more than most) to steer at its best. My previous query was aimed essentially at finding out whether the ' mixed results ' people have reported regarding wedges was because the wedges installed in their particular car actually moved the caster angle into or out of some 'desirable' range. In that regard I was very interested in Cliff and Terry's experiences and conclusions. I accept that caster angle can be set within a (relatively limited) range and be acceptable, and that where it should be set within the viable range is pretty much down to individual preference - the lower end for lighter steering, the upper end for better tracking. The better tracking higher end is more important to me, and would be particularly so for some one using a Datsun or similar steering box. A little more caster also provides the benefit of a larger margin for the springs to settle, etc. before tracking becomes a problem due to caster. To go back to Hans Holtman's original message, it seems to me that if someone is being advised to go to the trouble and expense of installing or removing wedges it would be good if they could find some readily available objective criteria for determining whether or not they had a problem that the wedges would be likely to correct. For example if, Han's car wandered excessively and a check showed that it had, say, 3 degrees positive caster then adding wedges would almost certainly make his car far worse UNLESS the wedges were installed 'back to front'. Just as if it had good tracking but overly heavy steering and 9 or so degrees of positive caster then adding the wedges the 'right way around', would almost certainly lighten his steering without adversely affecting the car's tracking. Despite the fact that T types are so rigidly suspended and sensitive to misalignment from a multitude of possible causes, it seems to me that many (most?) owners who have 'finished' cars may not be equipped or inclined to go back and thoroughly reexamine/remeasure each of the components that can cause poor handling / steering. However it shouldn't be too difficult to visit a properly equipped steering alignment shop and have the camber, caster, and toe (as well as the front & rear axle alignment and steering system wear) checked. Then an informed opinion could be reached as to whether or not to strip out the axles / springs, etc. for further work, or to just remove or install some wedges (even if that meant fabricating some suitable wedges). Sorry to be so long winded about this, but the above comments aren't aimed primarily at the experts such as yourself, Terry, Cliff, Chip etc., but more at those of us who are less knowledgeable / experienced and who may otherwise come to an incorrect conclusion that they should 'suffer in silence', because there could never be an alternative to a major strip down of their cars. I am look forward to learning more from your comprehensive papers on setting up T type steering systems. Once again many thanks. Bryan -----Original Message----- From: C Sherriff 100070.740@compuserve.com> To: C. Knight cliffknight@ic24.net> Cc: B Purcell purclb@pcug.org.au>; [unknown] MG-TABC@yahoogroups.com>; [unknown] hholtman@get2net.dk>; [unknown] TATERRY@aol.com> Date: Saturday, 2 June 2001 03:47 Subject: Re: [mg-tabc] TC steering

>Message text written by "C. Knight" >> >B Purcell wrote: >> Has any one out there who has experience of the affect of these >wedges >> on their car's handling, either done, or had someone do, an actual >> measurement of their car's caster angles?================================================ >Actually this is the wrong question it should be: > > >" Has any one out there who has experience of the affect of >incorrect steering angles and chassis set up etc on their car's handling, >either done, or had someone do, an actual measurement of their car's >caster angles? " > >On a number of occasions I have had to "sort" out a T Type and in >every case its a matter of overall alignment, setting the springs >correctly and straightening and aligning front ( and even rear ) axles. > >The castor and steering angles do make a significanr difference - >sometimes stuffing a wedge in helps mask that, sometimes not. >It everything else is right on a TC it helps, on a TA or TB it does not. > >I have been asked to repost my article on set up that is being printed >at present in the Octagon Bulletin and will do so over the weekend. > >Clive > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > >

[Gates Family]

I recently replaced my steering box with that from a Datsun 120Y as the original (with Tompkins kit) was beyond further adjustment - any "turning of the screw" simply seized the innerds, tho' the original remains on my garage shelf in case of need! So having resolved the more than 45 degree tolerance/play at the steering wheel (if I was a yachtsman I might have found the experience both challenging and invigorating) it was heaven on earth, except that the steering became far too sensitive at speed i.e. upwards of 55 mph (I stopped trying beyond 65 mph). So I removed the wedges and am happy to report a huge improvement in control - managed to scrape beyond 70 mph in comfort, assuming the speedo is correct and discounting the needle's fibrilations. For the fun of it I intend to insert the wedges in reverse order soon to see what effect the further increase in castor angle has on steering. I am considering attaching a damper/shock absorber (between chassis and steering rod linkage?) to provide an alternative resistance if this latter exercise proves worth the while. Also, I have now had all relevant angles checked out and they are within acceptable ranges per the brown book, Sherrel, et al. Lastly, my tyres - Firestone 19 x 4.5 inch tread - are narrower than Dunlop (or equivalent) - which may distinguish mine from others' experiences. Regards Joe Gates TC 8675 janus@iafrica.com +27 11 440 6993 +27 82 902 1060

[anngene@bellsouth.net]

Joe, I've already made that wedge swap (turning it around) in use with the Datsun steering box - and found it made the steering that much better. I'll be interested in your experience - and the use of the damper/shock absorber if you go that route. What size damper would you use - do you know? Gene

> > From: Gates Family janus@iafrica.com> > Date: 2001/06/04 Mon PM 09:17:00 EDT > To: B Purcell purclb@pcug.org.au>, C Sherriff 100070.740@compuserve.com>, > MG-TABC Group mg-tabc@yahoogroups.com> > Subject: Re: [mg-tabc] TC steering > > I recently replaced my steering box with that from a Datsun 120Y as the > original (with Tompkins kit) was beyond further adjustment - any "turning of > the screw" simply seized the innerds, tho' the original remains on my garage > shelf in case of need! So having resolved the more than 45 degree > tolerance/play at the steering wheel (if I was a yachtsman I might have > found the experience both challenging and invigorating) it was heaven on > earth, except that the steering became far too sensitive at speed i.e. > upwards of 55 mph (I stopped trying beyond 65 mph). So I removed the wedges > and am happy to report a huge improvement in control - managed to scrape > beyond 70 mph in comfort, assuming the speedo is correct and discounting the > needle's fibrilations. > > For the fun of it I intend to insert the wedges in reverse order soon to see > what effect the further increase in castor angle has on steering. I am > considering attaching a damper/shock absorber (between chassis and steering > rod linkage?) to provide an alternative resistance if this latter exercise > proves worth the while. Also, I have now had all relevant angles checked > out and they are within acceptable ranges per the brown book, Sherrel, et > al. > > Lastly, my tyres - Firestone 19 x 4.5 inch tread - are narrower than Dunlop > (or equivalent) - which may distinguish mine from others' experiences. > > Regards > > Joe Gates > TC 8675 > janus@iafrica.com > +27 11 440 6993 > +27 82 902 1060 > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > >

[brian bax]

Hello Joe, Since we last corresponded I have fitted the wedges back to front to increase castor and have found that this suits the Datsun steerin box very well making the car good in a straight line with just the right "weight" to the wheel. I don't think a steering damper would now be necessary for road use. Aren't these Datsun steering boxes wonderful? The Bishop Cam boys don't know what they're missing! Regards Brian Bax TC3550> -----Original Message-----

> From: janus@iafrica.com (Gates Family) > Sent: Mon Jun 04 20:17:00 BST 2001 > To: purclb@pcug.org.au (B Purcell); 100070.740@compuserve.com (C Sherriff); mg-tabc@yahoogroups.com (MG-TABC Group) > Subject: Re: [mg-tabc] TC steering > > I recently replaced my steering box with that from a Datsun 120Y as the > original (with Tompkins kit) was beyond further adjustment - any "turning of > the screw" simply seized the innerds, tho' the original remains on my garage > shelf in case of need! So having resolved the more than 45 degree > tolerance/play at the steering wheel (if I was a yachtsman I might have > found the experience both challenging and invigorating) it was heaven on > earth, except that the steering became far too sensitive at speed i.e. > upwards of 55 mph (I stopped trying beyond 65 mph). So I removed the wedges > and am happy to report a huge improvement in control - managed to scrape > beyond 70 mph in comfort, assuming the speedo is correct and discounting the > needle's fibrilations. > > For the fun of it I intend to insert the wedges in reverse order soon to see > what effect the further increase in castor angle has on steering. I am > considering attaching a damper/shock absorber (between chassis and steering > rod linkage?) to provide an alternative resistance if this latter exercise > proves worth the while. Also, I have now had all relevant angles checked > out and they are within acceptable ranges per the brown book, Sherrel, et > al. > > Lastly, my tyres - Firestone 19 x 4.5 inch tread - are narrower than Dunlop > (or equivalent) - which may distinguish mine from others' experiences. > > Regards > > Joe Gates > TC 8675 > janus@iafrica.com > +27 11 440 6993 > +27 82 902 1060 > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > >

[Frank O_ The Mountain]

In a message dated 6/4/01 1:35:13 PM Pacific Daylight Time, anngene@bellsouth.net writes: >>

[Gene Gillam]

TATerry wrote:

>Its a VW steering damper, I've forgotten which model but

very common. You put one end under one of your spring hanger bolts and fab a clamp to put on the track rod. Make sure you still have lock to lock turning capability before clamping it down.

[joecurto@aol.com]

I have just got into my shop TC 6773 (originally owned by Vaughn Monroe the singer) which is owned by a guy local for 22 years it has some sort of Datsun type steering box in it. I have never driven a TC with such light steering, it feels like a TD that you have partially jacked up off the ground. The customer is an older fellow and does not remember ever doing anything with the box so I can only assume that it was done by a previous owner. the installation has a casting by the chassis to space and mount the box, the box itself has an adjuster in an appendage on the main body. I am not really interested in what this is but if the currant Datsun box works this well than I am very impressed. Next time I see a TC with the conversion I am going to ask the owner for a spin and compare notes (Hi Ken Porter) Joe Curto [Non-text portions of this message have been removed]

[KEN PORTER]

Joe: The Red Car is available when ever you want it. I'll be at the following shows, British Cars by the Sea, The British Are Coming and the Jag show. Or come on out to the house; we can go to Canterbury Ales for an Old Speckled Hen. Ken TC 4147 joecurto@aol.com wrote:

> I have just got into my shop TC 6773 (originally owned by Vaughn >Monroe the singer) which is owned by a guy local for 22 years it has some >sort of Datsun type steering box in it. I have never driven a TC with such >light steering, it feels like a TD that you have partially jacked up off the >ground. The customer is an older fellow and does not remember ever doing >anything with the box so I can only assume that it was done by a previous >owner. the installation has a casting by the chassis to space and mount the >box, the box itself has an adjuster in an appendage on the main body. > > I am not really interested in what this is but if the currant Datsun >box works this well than I am very impressed. Next time I see a TC with the >conversion I am going to ask the owner for a spin and compare notes (Hi Ken >Porter) > >Joe Curto > > >[Non-text portions of this message have been removed] > > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > >