I get that but the 500 axle was made when the 169 Panda was still in full production meaning they had to make both and double stock some very large items.

The hub bearing stub axle is a separate casting with a decidedly odd shape. A wider version would have allowed the original Panda axle to suit all cars.

DaveMcT said:

I get that but the 500 axle was made when the 169 Panda was still in full production meaning they had to make both and double stock some very large items.

The hub bearing stub axle is a separate casting with a decidedly odd shape. A wider version would have allowed the original Panda axle to suit all cars.

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I'd guess that setting a jig to bend larger brackets was cheaper than making a new mould to cast larger stub axles. So we have to live with two different axles.

portland_bill said:

I'd guess that setting a jig to bend larger brackets was cheaper than making a new mould to cast larger stub axles. So we have to live with two different axles.

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Who knows. Maybe they have a contract for that shape of stub axle supplied complete with assembled brake parts.

At least the shallow stub axle / hub carrier is good for shimming to the axle. If the mod isn't 100% or if (as jrkitching says) the OEM is out of shape the stub can be shimmed to align the wheels. Fiat don't help with four fasteners but its all doable.

Looking at my new axle I could swear that one spring pan is sitting lower than the other. Perhaps only 1/4" but Im sure it's there. Who knows if the arms are parallel or centred properly.

OK so here's the news.

A 2015 Fiat 500 rear axle fits straight onto a 2007 Fiat Panda. I can't be bothered to wait for my home steam broadband so pictures to follow.

I used the complete axle with handbrake cables, brake pipes and hoses, hubs, shocks and springs from a 2015 500. This has 2" wider track, anti roll bar and 30% softer springs,

It looks standard but handle much better. Less body roll, smoother ride and corners like it's on rails. Yes it understeers (it's front wheel drive) but only when provoked. It understeered before but body roll prevented me trying too hard though I suspect the body roll was at least part to blame.

The downside:

It is riding lower at the back though not enough took strange. I had to adjust the headlamps angle by one "click". The 500 springs are longer than the Panda springs but are also 30% softer (Wikipedia). Time will tell. I might make up some spacers for the top mounts.

For anyone doing the job, its perfectly possible single-handed though it does take a lot longer.

Chock front wheels and jack the car high at the back. I used a trolley jack under the middle of the rear beam. Axle stands under the rear sill jacking points did the rest. I used 2"x 1" timbers to spread the load either side of the sill seam as the spare wheel tool kit jack does.

Unbolt the shocks at the bottom first, followed by the tops. I was glad to have a handy 600mm breaker bar. The bigger bolts are VERY tight. Also, they are self cleaning so can damage the treads if they pull sideways when removed. Use the jack under a spring pan to support the swing arms.

You can now pull the springs off and set them aside.

Disconnect ABS cables at body tub. The wheel end sockets will knock off their mounts with a gentle tap from a screwdriver handle.
Put a some thin polythene under the brake fluid reservoir lid. The reduces fluid loss when the pipes are separated.
Disconnect the handbrake cables inside the car. You'll need to remove the plastic trim and wind the adjuster right back. The cables pop out when you squeeze the little clips on the nylon end ferrules. Unclip the cables from underneath the cabin floor.
Disconnect the car end steel brake pipes at the axle swing arm mounts. The hoses are retained with push on clips and are not supposed to turn when you try to loosen the flare nuts. Ignore all that! You will need a 17mm open end to back hold the brake hoses. They will drip a few spoonful of fluid, so catch with rags or drip trays.

To reduce lifting weight I removed the brakes before taking the axle off but with two people this isn't necessary. Jack the axle centre and unscrew the swing arm mounts (three screws each side). Leave one bolt nearest to the wheel arch to last. I loosened with a breaker bar and used a power drill to run them out. Much quicker than a ratchet and gave me a spare hand to hold the axle.

Lower the jack slowly and watch the disconnected brake pipes are not snagged.
Drag the jack and axle out from under the car.

Refitting is literally the reverse. Fit the axle, connect the brakes and ABS. Fit the springs followed by the shocks. Do them top end first. Lining up the bolts and holes is always a struggle but the bottom end can't get cross threaded.

I wrapped each spring bottom end coil with self amalgamating tape followed by PVC tape. It probably a waste of effort but the old springs had really rubbed into the spring pans.

Connect the hand brake cable, bleed the hydraulics and refit the wheels.

Now go for a drive. The handbrake will most likely be too slack so don't refit the console until its been road tested.

DaveMcT said:

A 2015 Fiat 500 rear axle fits straight onto a 2007 Fiat Panda.

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Congratulations, and many thanks - this is a first class thread and will doubtless help many folks in the future. Hopefully this will also keep a few more Pandas on the road for longer than might otherwise have been possible - the 169 is a much underrated car.

jrkitching said:

Congratulations, and many thanks - this is a first class thread and will doubtless help many folks in the future. Hopefully this will also keep a few more Pandas on the road for longer than might otherwise have been possible - the 169 is a much underrated car.

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The car drives so much better. Smoother ride, less jiggle over rough surfaces, a lot less body roll, and understeer is well controlled. Although the rear axle track is now 50mm wider Ive not felt any negative effect on dual carriageway stability.

I would say anyone with a Panda 100bhp should seriously look at using the 500 axle. Wheel arch clearance will be the issue that I don't have as I'm using basic version wheels and tyres.

Now you just need some nice spacers for the front axle.

gr J

Any pictures of it fitted? ( See what it looks like with the extra width )

Really interesting btw!

Some pictures

Car jacked up ready using the wheel change jacking points.



Axle stripped of brake pipes, ABS wires, hubs and shocks (dampers). Springs about to go as well.



I wanted the brakes taken off to save weight lifting the axle out but the right hand side stud threads were rusted. Why don't Fiat use bolts on the hub carriers? I can't imagine the studs and nuts save costs or time in the manufacturing plant.
Sorry about the clutter - Im just an amateur. The job needs a 600mm breaker bar and a good set of sockets. The power drill was handy for running nuts off. A proper rotary hammer jobbie would have been better.



This is the new axle fitted.
You can see how the hub mount hangs out compared to the Panda axle. The Panda has a more flexible back axle and harder springs so you need the 500 springs. I got a full axle set with springs, dampers, brakes, hydraulic pipes (& hoses) and cables. My old spring pans were really rubbed by the spring bottom ends. I wrapped the first coils on my springs with self amalgamating tape and PVC tape. It might be a waste of time but better than nothing.


Fully fitted ready for the wheel.

Sloping ground but flat land is rare around my way. It looks OK but the back is about is about 20mm lower.

The car is lower at the back by maybe 20mm but its not obvious. I guess the 500 (and presumably the 100HP) rides a bit lower than the Panda.




Rear view looks nice. Those skinny Firestones grip really well.

It must be good - even my wife says the car drives more smoothly and handle better.

Excellent job all round, I'm going to have to change my rear axle soon but I hope I've sourced a good secondhand Panda item..time will tell. What was your reasoning for not using the original springs ? I can see the extra strengthening of the 500 unit, a round rod welded across but would that make a huge difference to the suspension stiffness ? Still, if it's working , leave well alone.

martroy said:

Excellent job all round, I'm going to have to change my rear axle soon but I hope I've sourced a good secondhand Panda item..time will tell. What was your reasoning for not using the original springs ? I can see the extra strengthening of the 500 unit, a round rod welded across but would that make a huge difference to the suspension stiffness ? Still, if it's working , leave well alone.

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It makes sense to use springs that are a year or so old over ones that are 9years old, even being softer, should handle a million times better..
Obviously with the addition of the extra width to the handling would have changed anyway.


I would assume you could use the panda springs though?

martroy said:

Excellent job all round

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Thanks

martroy said:

What was your reasoning for not using the original springs? I can see the extra strengthening of the 500 unit, a round rod welded across but would that make a huge difference to the suspension stiffness?

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The 500 and Ford Ka have (as you say) the additional anti roll tube across the beam. They also have 30% softer springs because Ford were not happy with the original 500's rough ride.

The breakers had a bare Ford Ka axle for £130 and a 2015 Fiat 500 axle with everything on it for £165. No competition. I got near enough brand new everything including hydraulic hoses, hand brake cables, springs, dampers, brakes and the axle of course.

I took the risk on the 500 springs giving a lower ride height but I can always refit the Panda springs. The Panda back tyre tread was four fingers below the wheel arch. It is now three fingers or less. The sills are pretty much parallel to the road but the front does look a little high.

On the other hand Ford were right to ask for softer back springs. The ride and handling are much better than the car was with Panda springs. My car has only done 35K so the dampers can't be too bad condition.

Three options:
Fit the Panda springs - No cost but the ride will be harder than it was and less compliant over bumps. I like the new handling.

Fit donut spacers under the rear spring top mounts - Doable and if I can get some nylon material so minimal costs.

Drop the front match the back - Maybe I should get some 500 front springs to match the 500 backs. Then again, around my way a higher ride is no bad thing.

In an earlier post , you reckoned there may have been a slight difference in the thickness of the cast iron hub carrier between the 500 and the Panda , DaveMcT, was there any ? Am I correct in guessing not as you used the 500 brakes and drums ?

martroy said:

In an earlier post , you reckoned there may have been a slight difference in the thickness of the cast iron hub carrier between the 500 and the Panda , DaveMcT, was there any ? Am I correct in guessing not as you used the 500 brakes and drums ?

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I think it was jrkitching who said the drum brake hub carriers are all the same. He was indeed 100% right. They are all the same. All of the wheel track difference is in the axle itself.

The 500 axle is a straight swap for the Panda. It would work with Panda springs, but as the 500 was supposed to ride better I used the 500 springs. Indeed the car does ride better with the softer rear springs.

For some reason Fiat used studs rather than bolts on the stub axle. The studs on my Panda were at least 10mm longer than necessary making them a nightmare to remove. Anti seize grease and heat shrink sleeve over the open threads would keep the corrosion out.

So now that you've replaced the axle, how would you go about getting wheel alignment now that rear track is wider?

is it just a case of extending the front track too?

The wheels are aligned but are not IN LINE.

Its not unusual. Smart Cars for example or any car with wider back wheels than front wheels.

The discussion about inconsistent back axle alignment on Fiats has made me notice that the car actually tracks better with its new axle than with the old one. So its likely one wheel (or both) was not properly aligned to the car body.

Not wanting it sound a huge big deal but will sort out the ride height. The cheap fix is spring spacers but i'll look into using 500 front springs to drop the front to suit the back.

The ultimate fix would be 500 front suspension. I very much doubt that's going to be simple swap job.

DaveMcT said:

The ultimate fix would be 500 front suspension. I very much doubt that's going to be simple swap job.

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With the rear, it is just the beam that is wider.
At the front, the strut tops may be further apart, if so, that presents a major problem, as using wider lower arms would mess up everything.

If however, the strut tops are the same distance apart, the struts and hubs would be different. Unless the strut mounting to the hub just fixes the angle created by the wider bottom arms.

Needs lots of careful measuring to determine what is different.

Whilst a wider axle on the rear of the Panda seems to work, with the standard wheels, a wider track at the front might cause issues when steering, especially if lowered too.

portland_bill said:

With the rear, it is just the beam that is wider.
At the front, the strut tops may be further apart, if so, that presents a major problem, as using wider lower arms would mess up everything.

If however, the strut tops are the same distance apart, the struts and hubs would be different. Unless the strut mounting to the hub just fixes the angle created by the wider bottom arms.

Needs lots of careful measuring to determine what is different.

Whilst a wider axle on the rear of the Panda seems to work, with the standard wheels, a wider track at the front might cause issues when steering, especially if lowered too.

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I can see a whole host of problems. I'd love to have a play but far too much stuff to do.