1987 3.2 Carrera Backdate project - Sladeys hotrod

[Nige]

Use your pillar drill next time

[sladey]

Yes that would have made sense if I could have clamped it level.

Anyway the JBweld option is looking good at the moment - it’s currently drying/hardening in the airing cupboard

[jtparr]

All part of the great learning curve……hope Douglas Valley do you well…i once ordered a part from them….never again…shite service as the part was no where near as good as they made out and they refused a return…..

[RobFrost]

All part of the great learning curve……hope Douglas Valley do you well…i once ordered a part from them….never again…shite service as the part was no where near as good as they made out and they refused a return…..

Return is a statutory right on anything bought online or mail order, although you may have to pay postage.

[sladey]

After thinking about it I decided to carry on with the JBweld route

The repair came out well - it covers a wider area than the hole itself (obvs)



Then spent today measuring, checking, greasing and gradually re-assembling it all. It was going together well until I came to add on the puck that is spring loaded to push the pinion against the rack.

As soon as I screwed it in I could no longer move the rack.

I can’t really work out why this would be unless the new rack is thick/sitting in a different position. I can’t measure against the original one because the pinion is a different size so the rack is also a different size.

The puck is one I bought from Chris Fennel and has a plastic end to it (which is good). Looking at videos online it was saying there should be a 0.2mm gap from the top of the puck to the housing, but on mine it’s actually standing slightly proud of the housing

I thought about machining the puck down but came to my senses quickly as I couldn’t machine it perfectly and I’d have one shot at getting it right. eventually I realised I would achieve the same effect by shimming out the cap.

I therefore made this shim


It made things quite a bit better but not good enough. I was an absolute ball-ache to make as I don’t have a 30mm hole cutter - I had to use a step drill which took ages and ages.

I’m onto something with the shim idea - I’ve ordered a 30mm hole cutter and with that I should be able to make a variety of shims in varying thicknesses so I can get the correct stiffness. from checking on line the ‘stiction’ needs to be around 0.5-0.8N/M to overcome it - so I should be able to keep trying them until it’s just right.


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[Gary71]

Not exactly bolt in then!

Mine felt good on the bench after rebuilding but wouldn’t self centre when driving so had to remove one shim from under the cap. So I’d tend on the loose side if you can.

[sladey]

That’s interesting. Your pic is of the other cover though - those shims are against the bearing.

I’m having trouble with the other cover - the one with the spring loaded puck

As you say though, not exactly bolt-in

[sladey]

OK so the steering rack arrived from Douglas valley - I decided to take the puck out and see what conditions it was in.

This explains part of my problem - my puck is on the left



It also wasn’t too badly worn


…But benefitted from a light sanding



With the other rack available I took the opportunity to measure the depth down to the rack from the edge of the bracket. This was the same so I couldn’t really work out why I was getting the extra tension.

Thinking more about it though, another reason for the extra tension was that the cap holding the puck in was bowed when I took it out. Maybe my original rack had worn and this coupled with the bowed cap meant it was OK. I straightened out the cap with a hammer so it sits flat - whilst giving more clearance Clarence, a bowed cap would let stuff in from the side so it wasn’t an option

I still needed to make another shim to get the tension right


And this shows it from the side with the two shims in place


I chemically blacked them later to give a modest rust resistance. Ideally I’ll recreate them in aluminium.

One question I can’t answer myself - when I took the puck out of the replacement rack it had these shims in place

They made up the gap between the top of the puck and the holding cap. However the spring means the puck is always forced away from them. That would mean the puck gets a ‘hard stop’ if the spring is overcome, and the ‘hard stop’ is its original position.

To replicate the same effect should I remake my big shims so that the inner hole is smaller than the puck diameter - but large enough for the spring to poke through? As I’m typing it this makes sense. Comments would be welcome.

EDIT: - I found this post from when I installed the fenn lane puck

viewtopic.php?p=533847&hilit=Puck#p533847

Looks like I removed 3 shims when fitting the fenn lane puck.

Anyway it looks nice on the bench. I was going to reinstall it today but I’m rethinking that whole shim thing now……



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[sladey]

It’s been a head-scratchy morning.

I found these manuals online - for a 914 rack but meant to be the same
Instructions for adjustment


And related pictures


So this says measure the amount by which the puck is extending out of the housing, and then measure the depth of the cap and the difference between the two measurements should be 0.2mm

I think this is wrong or relates to a different design of cap. The depth of cap is about 45mm. If I use the Fenn Lane puck then it protrudes by about 1mm (the original one is below the deck by about 0.5mm) - so the difference between the two is 35mm - a long way from 0.2mm

For my cap, the puck (and therefore any associated shims) sit against the base of the cap - they don’t go into the dimple


I’m therefore going to assume that it should be that the gap between the top of the puck and the top of the housing should be 0.2mm (that would make more sense)

I’ll still use my big shims as the spring seems to add too much stiffness to the steering, but I’ll cut new shims (with a 20mm centre hole instead of a 30mm one) so that the puck rests against them (rather than going through the hole in the middle) so I’ve got the required 0.2mm gap above the puck. My shims will therefore just be changing the amount of pressure applied by the spring.

If you’ve read this far well done.

That’s enough thinking for now.


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[jtparr]

Sounds good to me….if you can adjust once the assembly is on the car (cant remember…) just bolt it up and take her out for a drive….see how it feels…

[sladey]

Thanks JP - Yes I can - it’s not a big deal to change the puck area. Just making a selection of shims now so I can change the spring pressure easily


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[sladey]

Just to finish off this mini-project I re-fitted everything today. For people wanting to do this, the re-inserting the splined end of the steering shaft into the knuckle (?) is a bit of a ball-ache if you are on your own.

I had removed the suspension cross-member and refitted that to give me something to balance the steering housing on. I tried loads of different approaches and ended up shoving it up from underneath (jammed a bit of wood in at one point) to get the splined end engaged properly - then tightened up the pinch bolt - then once that was done I could righten everything else

I’ve got these bushes that apparently required no lubrication but they need to be compressed in before tightening things up so I adapted this bar clamp to help which made things a lot easier


When I was re-fitting everything I tried to move the steering to get better access to a bolt and it wouldn’t move at all. Immediate panic set in and I thought I’d massively cocked it up - until I remembered this



Took the clamp away and all is good.

Put everything together and went for a drive. It feels good - a nice upgrade. At slow speed it’s a bit heavier (but not ridiculous) but on the go it feels more precise especially with my bigger steering wheel and takes out the feeling that I’m moving my arms too much. I’ll drive it to work all this week to get used to it and shake down any problems

Then I might start stripping the suspension in preparation to fitting the tractive stuff when I get back from my holiday in April (needs to be fitted before driving holiday in May)


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[Gary71]

Glad it’s worked out

Can’t wait for the suspension story!

[jtparr]

Tres Bon…..

[Northy]

Well done Mark. Keep the updates coming, we all enjoy seeing the continued evolution of your car