I have always had a bit too much play in my S1 Fulvia Coupe's steering. When the car is jacked up I can not detect any play in the components, but while driving the steering on this car has always been more vague than what I was used to on my previous Fulvias (S2 Coupe and S2 Berlina).
I have replaced all the usual suspects, ball joints, tie rod ends, bottom wishbone bushes (top ones look good), idler box bushes, steering disc (not a cheap repro), checked and tightened subframe mounts... There might have been some slight improvement after these, but it is still not quite right. Maybe one of the new components are defective, but that is hopefully unlikely and I can't detect anything. The only conclusion I could therefore make is that my steering box is worn, which I always believed does not often happen. The car has documented low mileage of 130,000km, but the steering box had no oil when I opened it.
I have replaced the needle bearings, but this did not improve things either. I then tried a second hand box which turned out to be terrible, it had a strange binding feeling when turning under acceleration.
So after a long time playing around with different ideas/ parts I set out to find a new steering box. I don't trust that another used one will be worth the effort.
After a lot of searching a couple of new LHD boxes came up on Ebay, but my car is RHD. Then I found a NOS RHD box in Italy, only to be told after already agreeing shipping etc. (I live in New Zealand) that it is no longer available. It is still advertised as for sale months later, so not sure what the seller is up to.
Finally a NOS RHD box came up on Ebay, listed in Greece, so I jumped on that. I ordered it in Nov, but for some reason it got held up in transit in Australia for thee months! So today finally received it...
It turns out to be a LA9 box, which I believe is a HF box which has 3.25 turns lock to lock, vs. the standard LA10 4.25 turns. I think this might be a nice "upgrade", and as I am running skinny tires and without the HF camber changes it should not be too heavy. Time will tell.
Being a "new" 40+ year old part, I had some reservations that the bearings etc. would be corroded inside. So decided to open it, rather than to just replace the oil seals. I really struggled to get the top nut and adjustment screw seperated as the whole lot appears to be painted black after assembly. A bit of heat did the trick. Luckily it turns out to be assembled with some oil (not filled) and the bearings and surfaces are perfect.
A few observations after opening the box:
- I was surprised at how tight the horizontal shaft is shimmed (even with the vertical main shaft removed). You can turn it by hand, but it is pretty stiff. It will probably loosen up with use. I decided to oil this properly, but not to take the side cover of to disturb the paper gaskets and shims that are in there. A bit of a lesson for when I reassemble a box in the future that this can be slightly tighter.
- The setting screw was locked (and painted in place) pretty tightly as well. You can feel quite a bit of pressure around the middle point when you rotate it by hand. Probably also a fraction tighter than I would have set it but, again, I think it will free up a bit with use.
- the HF box appears, from memory when having the 1.3 box apart, to have a much smaller "knuckle" and roller, and a wider opening inside or more material removed inside, as it is much easier to align/ get the main shaft in position when reassembling.
Anyway, all that is left now is to swap it out and test it.
I have attached some pics, the green is a little oil I added.
Fulvia steering saga
Re: Fulvia steering saga
Good to hear you finally found a good steering box. Don't give up on finding a spare standard steering box. The lower ratio means higher forces.
The secret is indeed in the shimming of the worm. Any micro play there translates into milli play on the wheels.
There are shims between the front bearing and the housing and as you say under the rear cover. Under the rear cover is a stack of metal and paper shims which double up as gaskets. The paper shims don't survive disassemnly and washing. We make new ones from ultra thin plastic sheet.
The secret is indeed in the shimming of the worm. Any micro play there translates into milli play on the wheels.
There are shims between the front bearing and the housing and as you say under the rear cover. Under the rear cover is a stack of metal and paper shims which double up as gaskets. The paper shims don't survive disassemnly and washing. We make new ones from ultra thin plastic sheet.
