Rack and Pinnion install

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  • #1326

    BritBitsCanada
    Participant

    Hello,
    We are working on a customer’s 250 and we are trying to install the steering rack kit. When it was ordered, we were aware that there were not “instructions” per say, but it would be nice to see an y pictures of the rack installed to get an idea of how the brackets were designed to be utilized.

    Thank you in advance,
    Chris

    #1332

    Feathers
    Participant

    Parts
    (A) Steering Rack from Triumph Herald, Vitesse (‘Sports Six’ in the USA), Spitfire, GT6 or TR4, preferably new or reconditioned, complete with track rod ends. I understand that most of these racks have a 7-tooth pinion, as mine has, but the GT6 rack has a 6-tooth pinion. This will give more turns lock-to-lock so will be lighter at parking speeds but slower on the open road. In any case, either can be converted to the other, it’s only a matter of shims.
    (B) Steering Column assembly complete from one of the above cars, comprising: outer tube with horn button and brush, stalk switches and wiring, wiring channel, top mounting clamp and spring; upper tubular shaft; sliding crash joint clamp; lower shaft, and bulkhead seal rubber and plate. Note that the outer and inner upper tubes must come from the same model, though the lower shaft can come from a different one if that makes it easier to provide crash joint movement
    (C) Steering Wheel of your choice: Wire-Spoked wheels from early models of the above go straight on to simulate the original SP250 appearance. Other styles of Triumph or other origin can be fitted using conversion hubs. Most Triumph wheels are dished; assess whether a dished or flat wheel will give you the best driving position. My experience is that a dished wheel is quite satisfactory even for one who is as short as I am (5’ 2”) with the column fitted as far forward as possible.
    (D) Double-jointed steering column shaft section from Triumph 2000 Mk2. This is approx 16” long with universal joints both ends, one splined on. (Do not attempt to use the equivalent part from a Mk1, with rubbers instead of universal joints.) Again, use new if possible.
    (E) One pair of Rack Mounting Brackets. Two drawings are provided, one showing how I made mine in 1977, and the other showing how David Barton made his in 2005. There is an important difference produced by these two arrangements, and you have to consider which way you want to go. The rack height produced by my drawing enabled me to retain the original crankshaft-mounted fan, by mounting the rack beneath the fan tube. This has given me excellent results, with no bump-steer and no unusual tyre wear. However, David’s research and experimentation showed that the theoretical best height for the rack is about 30mm higher than that, requiring the removal of the original fan and tube. His simpler bracket design gives that greater rack height.
    (F) One set (2 pairs) Rack Clamps per drawing, or similar as available ready-made from Triumph parts specialists. (Triumph rubber mounts could be used, but steering is sharper with solid clamps and rubbers wear out and can come loose.) The drawing shows pairs made from single blocks and sawn through as the last operation in order to provide the clamping clearance. Making from separate pieces is OK as long as all holes line up and the clamping clearance is provided. Without this, the clamp halves will touch before the rack is gripped, and it may be loose.
    (G) One Top Steering Column Clamp Angle per drawing.
    (H) 4 bolts 5/16” UNF, 2 ¾” or 3” long, with 8 flat washers and 4 new 5/16” Nyloc nuts.
    (I) 4 new 3/8” Nyloc nuts. If other Nyloc nuts are disturbed, use new ones when replacing.

    SUGGESTED PROCEDURE: Please read completely before starting.
    1) If the Steering Rack: is second-hand rather than new or reconditioned, check it over: it should be free from play in all movements. However, all wear is easily dealt with by adjustment or shimming. Check for wear in the bush in the end of the rack tube opposite to the pinion: if the rack moves up and down (with a clicking’ sound), then the bronze bush can easily be replaced. Renew track rod ends and gaiters if doubtful. Renew the track rods themselves ifnecking’ or a wear ring around the ball end is found.
    2) Check for play in the steering column top bush: M.O.T. testers may fail a car for this. To replace the Rubber-and-Nylon bush, locate it by 2 rubber “Pimples” visible in holes towards the top of the aluminium column tube. Cut or drill them out and knock the bush out through the top of the column. Insert the new bush using rubber lubricant and a tube to push it straight until the “pimples” seat in the holes.
    3) Ensure the Double-Jointed shaft section has no play in the universal joints
    4) Before starting work on the car, disconnect the battery..
    5) Check which of the cables emerging from the bottom of the steering box work which circuit, and label them on the car-side of the connections, then disconnect them.
    6) Remove all of the Daimler steering gear, including the track rod ends but not the steering arms on the front suspension vertical links. First remove the central horn push and indicators switch by releasing the clamp at the bottom end of the central stator tube, where the cables come out of the steering box, and withdrawing the top and the tube out though the car (with the roof off!). Then remove the steering wheel as appropriate to the type fitted. Removal of the column-and-box is easier over a pit or on a lift: if you have to do this on the ground you will have to lift the front of the car about 2 feet (600mm) high. Be very sure that it is in reverse gear, the handbrake is on and the rear wheels are very solidly chocked. If lifting the car inside a building and with the bonnet propped open, check that the bonnet will not come into contact with something above when up. Support the front of the car on axle stands, stacked heavy timbers or some other hefty and secure structure, never on the jack. With the column removed, the car can be returned to the ground.
    7) Clean and paint all chassis areas now exposed. If you wish, you can now tack-weld 60mm discs of thin steel over the holes in the front suspension towers where the old column went through (or didn’t, on the other side), so stopping any more water and filth from entering the chassis at this point. Seal between the tacks with mastic.
    8) Remove the curved Cross-Brace between the front suspension towers. Remove the nuts from the bolts which hold the lower wishbone’s front pivot bracket to the chassis, on one side only. These are Item 59 on figure M1 in the Workshop Manual and on Plate 20 in the Spare Parts Catalogue. Do not remove the bolts, though. Fit the appropriate-handed Rack Mounting Bracket onto the bolts, grease the threads and refit the old Nyloc nuts. Then repeat for the other side.
    9) Assemble the clamps onto the rack and place on the brackets. Move the clamps outwards to butt firmly against the inner end flange of the pinion housing on the driver’s side, and against the welded-on steel flange on the other side. Centralise this assembly side-to-side on the brackets, then move it to the rear as far as it will go. This will bring it against the fastenings holding the fan tube to the pulley and torsional damper. If the nuts are facing forwards, undo them one-at-a-time and turn the bolts round so the bolt heads are forward; this will enable you to move the rack further back. If the fan tube has been removed, you can move it still further back. Now move it forward again so as to give enough clearance for the fitting of a fan belt. At this point, if your fan tube is present, check if there is fan-belt clearance between it and the rack below and the cross-brace above. If it is tight below, your engine may have sunk in time and require new front mountings and/or spacers to raise it up; if tight above you may have to remove the cross-brace (4 bolts) to change a fan belt.
    10) With the fore-and-aft position of the rack fixed, check that it is central side-to-side and parallel to the front axle line, not skewed. Now mark the bolt centres through the clamps onto the brackets. Remove the rack. Recheck that the marked holes line up with those in the clamps. Now remove one bracket and drill the holes at the bench. Then return it to the car and bolt up using two of the new 3/8” UNF Nyloc nuts. Repeat for the other side.
    11) Now bolt down the rack with the clamps and the 5/16” UNF fastenings, but do not finally tighten them yet. Replace the curved cross-brace.
    Slacken the locknuts on the track rods and, with both the front wheels straight, adjust the track rod ends so that they show equal threads and their tapers drop into the steering arms. Tighten the nuts under the tapers.
    12) If you wish to retain the SP’s foot dip switch, remove the lights-and-dip switch from the left side of the Triumph outer column, bend flat the two tabs left sticking up and use them to screw on a black-painted blanking plate. If you wish to convert to using the column dip switch, you will have to remove its sidelight wires and prevent the stalk from going into the upper sidelights-only position.
    13) Assemble the Triumph top clamp and its spring loosely around the neck of the column tube with the cables in the channel and with the angle bracket placed so the 1” vertical flange rises in line with the ribbed face of the clamp and facing the driver. Place the bottom of the column tube in the Daimler column clamp under the scuttle but not fully tightened, and position the top so that it lines up with the hole for the column in the bulkhead, when looking down its centre. With the clamp behind the dashboard, mark the positions of the holes in the angle on the inside of the plywood dashboard. Remove the leather-covered dashboard trim panel: it is held by trim clips and should prise off easily. Drill the two holes 5/16”dia. Fix the angle bracket using fastenings as available: ¼” coach screws (“cup squares”) fitted from the driver’s side require little or no additional work on the plywood; countersinking is required for countersunk screws and counterboring for hexagon heads etc. Carefully replace the leather-covered dashboard trim.
    A flanged self-aligning bearing can be mounted on the scuttle bulkhead for use as a lower steering column locator and to cover the large hole left by the original steering column. These are available in a variety of bore sizes, but the bore nearest to the 9/16”(14.29mm) dia. of the sliding shaft is 15mm and the bearing has part no SLFL15EC. This includes a ring that locks the shaft to the inner race, but may need shimming to make the shaft concentric within the race.
    14) Fit the steering wheel to the upper shaft so that the indicators’ self-cancelling cam (or pair of cams if an early column) point squarely to the right with the wheel in its straight-ahead position. Fit and tighten the central nut using a 1 1/16” or 27mm socket. Insert the upper shaft (with wheel) into the column through top and bottom bushes and assemble to the lower shaft with the sliding crash joint clamp left loose. Slip on and fit the bulkhead seal rubber and its plate, or a larger version if it is too small for your bulkhead hole (using flat steel sheet and old inner tube).
    15) Fit the double-jointed shaft onto the rack with its splined-on joint on the pinion, but do not fit its other end onto the bottom of the column shaft just yet. First check that the front wheels are straight and the steering wheel is perfectly in the straight–ahead position. Then slide the inner shaft up and down in the crash joint to couple it to the top of the double-jointed shaft. Insert and tighten the spline clamp bolts and nuts at the universal joints. Now check the angle through which the bottom universal joint deflects, and rotate the rack in its clamps to minimise this, if that is possible. Finally tighten down the rack clamps.
    16) The crash joint gives you some ability to lengthen or shorten the column; decide where you want it and tighten both the top and lower column clamps. Then slacken the locknut and central socket screw on the crash joint clamp and tighten the two smaller bolts. Finally screw in the central socket screw until it pinches and tighten the locknut. Reroute the cabling which used to go to the bottom of the old column, so as to couple up to the Triumph wiring. To do this you may have to unwrap some of the wiring loom back from where the cables used to emerge to give enough length, then re-wrap. You should find that the indicators’ colour codes match clearly: Daimler red, white and brown connect to Triumph red-and-green, white-and-green and brown-and-green respectively. The fourth is for the horns and connects to the Triumph purple-and-black. However, the Triumph horn cable is rather thin, and whilst I had no trouble with it during the four years before I fitted new horns with a relay, it seems sensible to use it to work a relay from the outset, or doubling its size to work horns without. Reconnect the battery and check indicators’ operation, including warning lights.
    17) In the middle of the steering wheel, insert the horn contact brush (transparent plastic tube with contacts both ends, one spring-loaded) into the hole on one side. Then see which way round the horn button fits and push it in at an angle. The horn may sound while you do this, if all is connected. The Triumph logo in the horn button can be painted over using black Humbrol, Japlac or similar.
    18) Recheck that the front wheels are as near as possible to parallel; adjust if necessary by rotating the track rods. Tighten the locknuts onto the track rod ends, and take the car straight to your nearest dependable garage or tyre shop to get the tracking set (1/16” toe-in with radial tyres, 1/8” with cross-plies). Remember how the indicators now work and be prepared for the steering to be much more responsive than you were used to before.
    19) On your return, check tightness of nuts on rack brackets and clamps, on track rod ends and on shaft joints.
    20) Check if the front tyres rub on the inside of the wheel arches on full lock. If they do, reset the steering lock stops: these each consist of a steel disc with a hole off centre, and this is bolted down onto a part of the steering bottom trunnion which projects inboard. There is a square-shaped lug at the bottom of the visible part of the swivelling upright, (which carries the hub,) and this is stopped from moving by its corners coming against the eccentric disc on both full locks. Resetting involves slackening the little bolt holding the disc and moving the disc around until its off-centre `bulge’ stops steering movement just before the tyre touches the inside of the wing. You should be able to get it to limit movement on both locks. Retighten the bolt, and do the same on the other side of the car.

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