F123C said:

Next question is what to do if the split pin holes in the spindle/nut don't align when tightened to the correct torque figure....
AL.

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you can become very sad like some friends of mine....
they make washers exact thicknesses (they know how to even calculate the thickness) so all the bolt heads line up the same and the nuts etc have flats that are horizontal when torqued up correctly...
Why? simply because they can...

Bigvtwin996 said:

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--------------------------------they make washers exact thicknesses (they know how to even calculate the thickness) so all the bolt heads line up the same and the nuts etc have flats that are horizontal when torqued up correctly...
Why? simply because they can...

Click to expand...

I thought everyone did it this way.

AL.

Dealing with this thing every single day. In aviation world that every single nut goes with a specific torque the pfoblem is that split pin has to be perfectly align. So sometimes there is always a main washer and then secondary washers to adjust accordingly. Sometimes we are just trying different nuts until we find the appropiate. I will support each side with my jack and without the wheel on and tight my shelf locking nuts. Really don't care if it is going to be 95 or 100 or degrees. Can you imagine how many old school mechanics know all those little details? Very few to none i guess. Of course if is good to analyse it and discuss it by the book here but in real world things are lot flexible.
Thomas

Hi Thomas,

I worked for a while in Aircraft Overhaul (Pratt & Whitney JT 8?/9D? fuel systems), also in an Aircraft Maintenance & Overhaul Support Services workshop, so I have some ideas how pernickety and rigorous the requirements are in this field. :bang::bang:

I also worked in the Middle East in charge of maintenance of a Royal Fleet of high-performance, luxury and armoured vehicles. If anything bad had happened to a Royal Personage while driving a vehicle I had signed-off on, my head would literally have been 'on the chopping block'
So I took zero chances and double-checked everything....

But, back in the real world, I doubt many Mechanics would even bother using a torque wrench to tighten the above suspension arm nuts, let alone bother supporting the arm in the correct (what was it, at 95? degrees, get outta here!!or else, words beginning with F) position before tightening. The nuts would be tightened 'enough', possibly indicated by a slight grunt (not all Mechanics grunt!). If the split pin holes didn't align, then you either tighten a little more or else loosen slightly (more likely loosen as it's less effort!).

AL.

I've often thought about Fiat kingpins and those pesky bushes. Assuming that the bushes bores in the housing are circular and in-line with each other (am I assuming too much?), I can't help but wonder why the bushes can't be pre-finished to the correct size.

Also wondered if anyone has made their own bushes possibly from another material. I remember having bushes made from a Nylon? type material (iirc it was called Tufnol) to replace motorcycle swing-arm bushes. I wonder if this or a similar material would withstand the loads experienced?

Also wondered if it might be possible to use caged needle roller bearings (e.g. as used in 2 stroke motorcycle small end bearings) in place of bushes (with a little machining of the bush bores in the upright).

Also wondered if anyone has modified the way grease gets to the bushes. The original (iirc) one grease point above the top rubber/metal bush and the grease then trying to find it's way down to the bottom bush always seemed overly optimistic to me. In the past I drilled and tapped the upright at both bushes and fitted grease nipples, but only on my own car (i.e. at my own risk). Never had any problem after that. Some say to use gear oil (not EP type) instead of grease.

Al.

F123C said:

I've often thought about Fiat kingpins and those pesky bushes. Assuming that the bushes bores in the housing are circular and in-line with each other (am I assuming too much?), I can't help but wonder why the bushes can't be pre-finished to the correct size.

Also wondered if anyone has made their own bushes possibly from another material. I remember having bushes made from a Nylon? type material (iirc it was called Tufnol) to replace motorcycle swing-arm bushes. I wonder if this or a similar material would withstand the loads experienced?

Also wondered if it might be possible to use caged needle roller bearings (e.g. as used in 2 stroke motorcycle small end bearings) in place of bushes (with a little machining of the bush bores in the upright).

Also wondered if anyone has modified the way grease gets to the bushes. The original (iirc) one grease point above the top rubber/metal bush and the grease then trying to find it's way down to the bottom bush always seemed overly optimistic to me. In the past I drilled and tapped the upright at both bushes and fitted grease nipples, but only on my own car (i.e. at my own risk). Never had any problem after that. Some say to use gear oil (not EP type) instead of grease.

Al.

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Well you are right things could be better here but on the other hand simplicity is preferable for me. Even with those bushings if you are lubricating the system every 6-12 months and with the use most owners having with this car ( i tend to use it every day by the way because it is excellent for city traffic etc) i think that it can stand lot of years of use.

Here s poor man's torque wrench for final torque of stake nut. I staked the nut but I really don't feel safe at all with it. I don't like the resistance that staking provides. Nut has some minor play and I feel that the rotation of the wheel may turn the nut and overcome staking. What do you think about it.

gordinir8 said:

Here s poor man's torque wrench for final torque of stake nut. I staked the nut but I really don't feel safe at all with it. I don't like the resistance that staking provides. Nut has some minor play and I feel that the rotation of the wheel may turn the nut and overcome staking. What do you think about it.

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I like your torque wrench but I don't think you need it for the front hub nut. I judge it all by "feel" as you do with old-fashioned bearings in a bicycle.
Even if you get a slight feeling that the nut is not very positively secured I doubt that the rotation of the hub will dislodge it except in a case of complete seizure and that would be a good thing.
As the driver's-side hub (on your LHD car) rotates anti-clockwise when driving forwards, the bearing rollers cause a very slight force (precession) that causes the inner-race to creep. This "creep" will have a positive tendency to persuade the hub-nut with which it is in contact to move in the direction of tightening.
This also applies on the opposite hub as it has a reverse thread to match the fact that its wheel's rotation when moving forward is in a clockwise direction.
I find the best thing with those nuts is to give just one determined whack with a heavy hammer and an old, blunt steel chisel.

Hi Thomas,

As mentioned before, I worked in a Fiat Main Dealership back in the day.

We used to first tighten the hub nut to roughly 25 lb.ft while turning the drum/hub to settle the bearings (we didn't use a torque wrench for this, all Mechanics know what 25 ft.lbs feels like ). Then loosen the hub nut to where it's free and re-tighten it using firm hand pressure on a socket extension with a socket attached. (i.e. no ratchet or lever, just gripping the extension bar as if it were a screwdriver). This gives very light pre-load of the bearings. Then stake the nut in place.

There was a Fiat Special Tool for staking the nut - it looked like a large pliers/welding tongs and fitted end-on not side-on the nut i.e. it was used in-line with the stub axle. Inside one jaw of this pliers was a little pip of metal which staked the hub nut to the groove in the stub axle.These tools came in various sizes to suit the different Fiat models.

Oftentimes, the correct tool was m.i.a. so I just used a cold chisel with the cutting edge ground to a round edge. some others just placed a large screwdriver edge-on to the area to be staked and bashed it.

I never really liked this arrangement i.e. staking a nut in place. It means almost surely having to buy new nuts each time. I preferred what is used on other makes i.e. a castle nut and split pin, or alternatively a plain hub nut over which is placed a special cap, which is indexable to align with a split pin hole in the stub axle, plus a split pin.

I wouldn't worry about rotation of the wheel causing the nut to unscrew. I don't think this can happen as the heavy washer under the hub nut is keyed to the stub axle and would prevent this. I've even seen hub nuts barely staked in place, really just squashed a little using a hammer and drift (so that the nut could be re-used?) and these didn't come loose.

Al.

Actually i was expecting that the rotation of tightening had to be in the direction of wheel rotation. For drivers side ccw and for left side cw. But it is designed the opposite way. I'll tell you What, previous owner had also made a hole in the shaft and put a cotter pin, he actually used one castle and one stake nut. So I might use a cotter pin also. Al I get your point about the big washer before the nut and you are right butp I just don't feel right about this. I'll give it a seccond try tommorow since I have spare nuts.

Iirc, the VW Beetle front hubs had a type of split ring nut (like a clamp) which was locked in position by a socket head cap screw (allen screw).

The type of adjustment cap with slots for a split pin was used on the front hubs of rear-wheel-drive Fords, Opel (GM) etc.

Trucks often use an adjustment nut and a locknut (jam-nut).

I suppose one could always clean the nut and stub axle threads and use Loctite.....

AL.

Over and above.

gordinir8 said:

Over and above.

Click to expand...

Hi Thomas,

Can you reveal how you cleaned up that brake drum?

Nice work on cleaning up and painting the underwing and suspension area!

Regards,

AL.

Well to my surprise front drums seems to be new I just gave them a slide cleaning with a Scotch-Brite. Those seems the only new parts the previous owner had changed on this car!! But usually when I want to remove rust I'm using the electrolysis method which always gives good and fast results.

So after almost 3 months car is back on the street and god knows how much i missed it After front system rebuild car handles much better and less noises comes to the cabin. Within a year i managed to rebuild almost all the mechanical parts and interior except the engine and gearbox. I had a great time with it but the most i enjoy was the discussions here with you guys, i would like to thank each one of you from your support. Next chapter will be painting which i hope to do before this summer.

Thomas

It's been a pleasure to help you Thomas---as I have said before, when compared to some forums that I have sneaked a look at, this forum is probably the most friendly , and helpful to each other. Despite the fact that it we have only just got into March, if it is a nice bright day, I use the Fiat to blast around in, loik wot oi have dun today!

I second what Tom (the hobbler) says. It's been a pleasure to help you Thomas.
I think many of us have also learned from your experiences, experimentation, advice and the great information you've shared with us.

Ditto about this forum being a really friendly place.

I think there's something about the 500, it just seems to attract nice people. It certainly puts a smile on the face of most people who encounter one. So we owe it to society to get as many of these great little cars back on the road and keep them there.

AL.