Impreza steering rack mod

[Rowge]

Hi All, my serp belt is now fitted correctly, I plan to do a parts list with prices, and a step by step guide, unable to get a TVR made PAS reservoir bracket, so will have to make one, standard one may not fit my carbon plenum anyway

[Rowge]

Went out for a drive last Sunday, the rack behaved beautifully, car now easy to get in and out of the garage, very enjoyable quick right turns, it feels like an impreza, (owned 3 over the years) steering wheel slightly off centre, MOT next week plus full geometry 4 wheel set up. Very happy with the general feel at legal speeds.

[Rowge]

sorry guys been busy on other things, I found the UJ from car builders was better, see page 6, with regard to the pinion, I cut mine using an angle grinder you must cut slowly leaving the pin intact you will also notice the intact small diameter, the second photo shows the removed original Scooby spline and the diameter that fits over this small diameter, I used the small remaining diameter to mount a 17mm AF nut using a g clamp to hold the nut in place, this then allowed me to file the 17mm hezagon on the pinion using the nut as a guide.


Hope this helps/makes sense, will try to put the parts list together this week
Cheers Steve

[Rowge]

A better photo showing the internal diameter from the removed end of pinion

[Rowge]

Spacers from eBay, tried 25mm then 20, which started to bend the 5 mm plate, finally used 22mm made up of 20mm plus a thick washer, I filed the 17mm hezagon onto the Scooby pinion, until the KA UJ was a snug fit, imo the car builder solutions UJ was better due to the 8 mm clamp bolt locking the 9/16 splined shaft on the other end of UJ, also push the HEx on the UJ as far as possible on to the rack pinion hezagon before you file the slot that the 8mm clamp bolt locates into, bit hard to describe, hope this makes sense

[Rowge]

Looking good, couple of things, make sure you replace the round shim that positions the pinion to the rack, mine was 4 shims of 0.025" so 0.010" in total or 0.25mm in new money, also during the fitting you may have to move the KA UJ towards the rack to increase the clearance to chassis, I used a titanium nut and bolt as the head size was smaller, I see you have added another locking bolt, this may make things worse with regard to clearance, or may be better as you have mounted yours further from the rack than mine. Anyway check for clearance before making the 9/16 shaft between KA UJ and column UJ, couple more pics of mine

[Rowge]

Better photo of UJ fitted and clearance nut to chassis upright

[Rowge]

Parts used to convert my 1996 Manual steering Chimaera 500 to power steering using Subaru Impreza steering Rack

TVR Parts

TVR OE reservoir bottle and bracket (bracket hard to find so had to make one)
TVR OE Power steering Pump
TVR all low pressure power steering hoses
TVR Power steering UJ (Steering Column end)
(Did not try the TVR manual steering rack UJ, this may have given more Clearance to chassis rails?)

Subaru Parts

Classic Impreza rack (1998)

OE Impreza square mounting brackets

(Note the Impreza mounting brackets can be 25mm or 30mm wide so measure before purchasing the new mounting rubbers, this will also affect the width of the 120mm long plates, my brackets were 30mm wide, so the 25mm plates were perfect)

New square Rack mounting rubbers to fit 25mm or 30mm wide brackets

Rack boots if required

To be sourced

2 off plates that fit between rack mounts and chassis mounts 120mm long, 25mm wide, 5mm thick, stainless steel, Drill 2 off M10 holes 80mm pitch in each plate
4 off M8 bore, OD 20mm, length 22.5mm stainless spacers to fit between Impreza brackets and chassis mounts,
4 off M8 bolts 40mm long

2 power steering pipes (similar to brake pipes) that are required due to rotating the rack pinion 180 degrees, so 2 off 1/4 OD pipes and 4 off M12 * 1mm pitch male ends, Any shop that makes brake pipes will make these up for you if you supply the male ends (ebay) sorry did not measure the lengths

1 off splined shaft 9/16 36 spline on both ends, overall length 320mm long, 250mm between splines, so 35mm spline length on each end (Note, measure before purchase as this length may vary from car to car )(Car builder solutions shaft is 400mm overall length)
KA type UJ, 9/16 spline to 17mm Hexagon (car builder solutions)
Hydraulics allowing the use of common AN-6 hydraulic hoses

High pressure hose braided, AN-6 female fittings one of which has a 90 degree end, mine was 114cm long
1 off AN-6 fitting, 90 degree female both ends (low pressure rack)
1 off AN-6 Male to 12.7mm (0.5mm ID Hose barbed (low pressure rack)

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Pirtek Harlow - 01279 427300

2 off M16 1.5mm pitch, part number = 491615/791615 aluminum/steel
(1 for rack, 1 for TVR power steering pump high pressure)

1 off 14mm 1.5 mm pitch, part number = 491415/791415 aluminum/steel
(1 for rack)

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Various UJ clamping nuts and bolts are required, these will depend on the clearance available also Jubilee clips for the low pressure hoses

Cheers Steve

[Rowge]

Well done I also remember those fine words being spoken during my build, they will be long gone during the test drive😄

[Rowge]

Blimey 6 months since my last post, been busy on other projects, anyway had slight play in my steering, traced to the fiesta UJ, have quite a collection now see pic, the new genuine ford units joint is very tight and has zero play, the other 2 have play even the one in the centre which I have not used, so it seems the Ford one is much better quality. I am going to modify the ford one by removing approx 3mm from the front face and maybe open up the 8 mm hole to 10mm to engage with the pinion shaft, although the 10 mm nut bolt combination reduces the clearance to the chassis,.will see how it goes