what is the method for changing kingpins?

[phreak97]

theyre actually on a 500 but I assume the method is the same..

[GTMaster]

(This is how i did it on my 126). First disassemble it from the car (brake back plate, wheel hub etc.), lot easier to work with it if everything is removed off it. Remove the metal/rubber bush (either by making your own tool or by pushing it out in one of those hydraulic bush removers), or you might be able to push out the middle rubber part after which you can saw out the outer metal part of the bush. The kingpin is secured by a pin in the middle part which you can hit out with a spike and hammer. Get a rod that's approx. the same diameter as the kingpin and start hitting it out from top to bottom. Usually it will push out the small bottom plate but if it's rotted in then you'll be spending a good time pelting it. If that's the case use WD-40 or something like that (and use a big hammer ). Once it's out you can remove the spacers (you'll probably will have to get one spacer per kingpin custom made as the ones in the kits are usually too thin.) Check the surfaces of the hub and the other part of the kunckle where the spacers meet, there'll usually be grinding marks and will have to be smoothened out. Next remove one of the kingpin sleeves (the other one should remain in place as a guide for broaching the new sleeve) by using a rod similar in diameter to the sleeve. Afterthat it can go together with the new sleeves, kingpin, spacers, grease (might be worth changing the grease nipple too) bottom plate (which has to be secured in place by hitting it in the middle) and bush (which can be pushed in using a vise).

[ChrisRLewis]

You will also require a Fiat Reamer Part No 90316

[phreak97]

yep, thats pretty much how bs I was expecting.. but I'd hoped it was less trouble than that.
I wonder if a 126 knuckle etc will bolt straight on? I've got lots of already assembled second hand 126 ones..

[gsxr126]

126 stubs will bolt straight up. Just a matter of making control arm adjustments as you'll get loads of positive camber due to the 500 spring being shorter than the 126. But you can always take a gas axe to the spring and make it longer if you dont have enough adjustment in the arm.

[phreak97]

I didnt even know there was a camber adjustment in the front.. Is it just shims? Or what?

[GTMaster]

Yes there are washers/spacers behind the top arm (you can also adjust the caster with them as well).

[Rusty's Uncle]

Regarding the reamer that Chris showed , I have seen one or two pop up on eBay over the years but they seem to be hard to get your hands on. I have got bye in the past by making careful use of a suitably sized adjustable reamer  [-/

[ChrisRLewis]

Regarding the reamer that Chris showed , I have seen one or two pop up on eBay over the years but they seem to be hard to get your hands on. I have got bye in the past by making careful use of a suitably sized adjustable reamer  [-/

The main problem with adjustable reamers is that their length is to short, the both bushes have to be reamed in line.  If you do have access to a suitable adjustable reamer of the correct length then there shouldn't be a problem.

[Rusty's Uncle]

Yes that is right Chris and why I said "careful" and "suitable" . By suitable size I meant one that could be taken down to the bore size of the bush then eased up a thou or two at a time to maintain the alignment on the bore and attain the right fit on the king pin. Then with one bush done you can run through to the other bush to get the fit and alignment on the pin. Depending upon the king pin kit that you have , as the bush material may vary , it is sometimes a good idea to rotate the reamer in the reverse direction which will give the cutting edges a negative rake & stopping it taking chunks out of the bush. I said careful because if you take out too much you are back to square one 
Also useful to have a suitable drift that fits the bore of the bush then steps up to just under the size of the outer O/D. Very simple lathe job and great for removing old bushes & fitting the new. Also a suitable size pin punch to remove the self locking pin is useful  [-/

[Darrell]

How would one adjust caster? I know about adjusting the camber coz I've done that before and makes a big diference to how light or heavy the steering feels.

I think the answer to my reamer issues would be to visit Rusty  [-/

[gsxr126]

Careful Darrell, you'll confuse Smallcox with all these issues, and we all know you said RIM in your santa post.

The only way I could see that you could adjust caster would be to have an uneven amount of shims/spacers front to rear.

[Darrell]

Thats his fault for not reading properly, the rim issue was well documented with a reference to an e bay item lol

Uneven amounts of spacers...I see what you saying, more spacer on the foremost post will increase caster, clever, never thought about that before, might have a play as my camber is too much, I'd prefer it closer to original spec. and then lower somehow from there.

Anyone ever tried 'relaxing' a spring a bit with a gas axe?

[gsxr126]

I would be careful with caster adjustments though. I never thought about it before either, but my concern would be the play that you might get in the control arm from having it bolt up at an angle to the studs and those studs arent very strong either so the stress of caster adjustments may cause them to fail.

I have relaxed a spring with the trusty old gas axe. Get a rule across the eyes and measure from the centre of the top of the spring vertically to the rule line. This will give you an unsprung height that you can use as a guide to how low you want to/can go. Then one leaf at a time, main/biggest leaf first, heat the spring with weight on the top centre so you get an even flattening of the leaf. Check to measure height diff to original, then once happy, flatten the others to this curve. Thats my method anyway. I think Jan-in-UK has mentioned doing this to one of his cars too. Maybe he can give his take on how to do this.

This does increase track though Darrell, maybe something you might not want with those retro alloys of yours. You could mod and fit your 500 spring as they are supposed to be shorter than a 126

[Darrell]

Yeah I was surprised to hear the 500 spring is shorter.

I always thought they were the same.

Mine's looking a bit knock-knee-ed in the front so thought relaxing the spring a bit might relieve this a bit. I have means to do my own tracking via a scrub gauge so not too bothered about that.

Think I might give the caster a miss but worth trying to see if both sides are the same

I'd have to pull the wheels of and do some head stratching but I'm buggered if I'm paying the silly prices for a lowered spring Gas axe and an angle grinder can fix most things [-/