Peugeot 406 Coupe - 3.0L V6. Complete refurb... very slowly
Discussion
roadie said:
I think these cars are such an elegant and pretty design so it is fantastic to see one being kept going and seeing use. Going down the OEM+ route with some choice mods would be great to see.
It's definately one of those cars where when I went outside after giving it a clean I just admired it, even walking back to it in the car park, the lines are so good, no silly overdetailed areas trying to grab your attention, just a gorgeous sillhoutte.
Okay, on with the story, so, we don't let a little thing like engine fires stop us, fortunately I got it fast enough it barely did any damage - it melted a little of the wiring loom for the variable power steering solenoid - easily fixed by just crimping a new connector on, the heatshields for the exhaust were damaged - not by the fire but by the powder extinguisher, it's corrosive to some stuff, fortunately I had spares in my box of random 406 parts so I just swapped those out, and it melted the boot on the steering rack.
Me being me, I pulled the rack out completely, rebuilt the rack, fitted new track rods, new track rod ends and new boots and grease...I mean if you in there anyway, may as well get it like new, right?
The pipe that split on the steering rack is a common issue for leaking, it goes straight into the rack and then immediately has a 90* bend over the subframe, and they eventually split and weep. What made it worse in my case, was someone had already tried to repair the leak before and basically cut the split bit off and put a repair section in with hose clamps. Then when it split further down instead it sprayed on the manifold instead of just weeping. Previous idiot owners bodging things, always fun...
Anyway, I wasn't replacing it with an OE pipe of unknown condition, so I went to my local hydraulics place and made up a proper solution, some reinforced steel/kevlar hydraulic hose, swaged on low-profile bango end to get rid of the 90* bend out of the rack completely, and then an adaptor on the other end to firt down to the Peugeot pipework.
It all fits nicely under the OE steering rack shield, looks OE, and gets rid of the failure point completely.
However, to get the steering rack off, first I had to drop the front subframe, and that's when I found out why the steering sometimes felt like it would almost shift and pull slightly one way or the other - I'd been through allsorts trying to find this for a few weeks, couldn't find any real play in any suspension joints worth worrying about.
However, once the subframe was actually off the car and under no load....well the bushes looked a little worse for wear:
Well, okay, they were shot as hell.
Now, I tried to get replacements for these, however the only aftermarket ones are some no-name specials floating around on ebay, etc, which people said start to crack after a while, Peugeot don't make them any more, and the one dealer I found that had them in stock wanted something like £260 for a set.
So after some measuring and some CAD work, I made my own instead, the originals go in with a nylon plastic surrounding the bonded rubber bush to make them easy to fit, so I replicated that with some 3D printed PET-G inserts with 90A shore polyurethane elastomers inside them:
And then some machined up washers that clamp them in place on the car which replace similar thin steel washers that are there OE but allow me to preload the bushes:
Which looked rather better than the OE ones!
I kept the stock geometery because I didn't want to mess with anything until I'd been through the car refreshing stuff, so these drop the subframe exactly where Peugeot intended...for now
Now, no doubt the NVH might have been better with a new set of OE ones - but even with these hard poly ones in the ride quality is superb. There is maybe a tiny bit more cabin/road noise with them fitted but that's all, nothing you'd notice without actually looking/listening for it back-to-back.
On the upside, it fixed the occasional odd feeling/pulling - I guess it was fine most of the time but it was most noticable under heavy braking/loading downhill, when there was enough force you felt the subframe suddenly shift just a little bit and that was the oddness.
It also made the steering the rest of the time much more direct - I've driven a couple of 406s and they all had a slight vagueness I put down to PAS but it's not, it's those subframe bushes, suddenly the steering felt much more like the old 306 and 405 - far more immediate and direct on turn, more grip on turn in too.
I know the 406 was always revered for having a decent chassis but it always came with the disclaimer of "but not quite as fun as its predecessors" - just the front subframe bushes went a decent way to fixing that alone, now you could get a little oversteer to correct a line on turn in. It's not lively, but tightening your line on throttle alone had much more effect.
Anyway, subframe on, rack on with new parts, PAS hoses fixed, damage repaired and thankfully, I guess she came out of the little fiery tantrum a better car for it. Could have been a lot, lot worse! Plus I got to make shiny things
Me being me, I pulled the rack out completely, rebuilt the rack, fitted new track rods, new track rod ends and new boots and grease...I mean if you in there anyway, may as well get it like new, right?
The pipe that split on the steering rack is a common issue for leaking, it goes straight into the rack and then immediately has a 90* bend over the subframe, and they eventually split and weep. What made it worse in my case, was someone had already tried to repair the leak before and basically cut the split bit off and put a repair section in with hose clamps. Then when it split further down instead it sprayed on the manifold instead of just weeping. Previous idiot owners bodging things, always fun...
Anyway, I wasn't replacing it with an OE pipe of unknown condition, so I went to my local hydraulics place and made up a proper solution, some reinforced steel/kevlar hydraulic hose, swaged on low-profile bango end to get rid of the 90* bend out of the rack completely, and then an adaptor on the other end to firt down to the Peugeot pipework.
It all fits nicely under the OE steering rack shield, looks OE, and gets rid of the failure point completely.
However, to get the steering rack off, first I had to drop the front subframe, and that's when I found out why the steering sometimes felt like it would almost shift and pull slightly one way or the other - I'd been through allsorts trying to find this for a few weeks, couldn't find any real play in any suspension joints worth worrying about.
However, once the subframe was actually off the car and under no load....well the bushes looked a little worse for wear:
Well, okay, they were shot as hell.
Now, I tried to get replacements for these, however the only aftermarket ones are some no-name specials floating around on ebay, etc, which people said start to crack after a while, Peugeot don't make them any more, and the one dealer I found that had them in stock wanted something like £260 for a set.
So after some measuring and some CAD work, I made my own instead, the originals go in with a nylon plastic surrounding the bonded rubber bush to make them easy to fit, so I replicated that with some 3D printed PET-G inserts with 90A shore polyurethane elastomers inside them:
And then some machined up washers that clamp them in place on the car which replace similar thin steel washers that are there OE but allow me to preload the bushes:
Which looked rather better than the OE ones!
I kept the stock geometery because I didn't want to mess with anything until I'd been through the car refreshing stuff, so these drop the subframe exactly where Peugeot intended...for now
Now, no doubt the NVH might have been better with a new set of OE ones - but even with these hard poly ones in the ride quality is superb. There is maybe a tiny bit more cabin/road noise with them fitted but that's all, nothing you'd notice without actually looking/listening for it back-to-back.
On the upside, it fixed the occasional odd feeling/pulling - I guess it was fine most of the time but it was most noticable under heavy braking/loading downhill, when there was enough force you felt the subframe suddenly shift just a little bit and that was the oddness.
It also made the steering the rest of the time much more direct - I've driven a couple of 406s and they all had a slight vagueness I put down to PAS but it's not, it's those subframe bushes, suddenly the steering felt much more like the old 306 and 405 - far more immediate and direct on turn, more grip on turn in too.
I know the 406 was always revered for having a decent chassis but it always came with the disclaimer of "but not quite as fun as its predecessors" - just the front subframe bushes went a decent way to fixing that alone, now you could get a little oversteer to correct a line on turn in. It's not lively, but tightening your line on throttle alone had much more effect.
Anyway, subframe on, rack on with new parts, PAS hoses fixed, damage repaired and thankfully, I guess she came out of the little fiery tantrum a better car for it. Could have been a lot, lot worse! Plus I got to make shiny things
Edited by PhillipM on Thursday 16th February 14:05
carinaman said:
Are front bumpers too big and too much material to be able to 3D print?
You'd be better off getting them made out of Carbon fibre probably. I used to work in heat exchanger design and part of that meant testing full sized car dashboards with all the vents etc in place. We'd get these printed and they'd be about 25K each. Needless to say we never tested RHD variatnts lol Yep, and if you make them in glued together sections you've then got a huge amount of hand finishing work, etc. Traditional processes are better for replicating the bumpers.
Of course if you wanted to alter them slightly, add modern wind deflectors in front of the tyres, fixing points for splitters, etc, you could easily 3d print those, attach them and then take a mould from the whole thing, that's where the tech is used better.
Of course if you wanted to alter them slightly, add modern wind deflectors in front of the tyres, fixing points for splitters, etc, you could easily 3d print those, attach them and then take a mould from the whole thing, that's where the tech is used better.
Oh, I forgot another little trick while I was under there refitting the subframe - the Brembo calipers on these have a real issue with the pads squealing like a banshee at low speeds, and to counter that and reduce pad drag, Brembo fitted them with these big wedge shaped springs that push on the top of the pads, shoving them downwards but also outwards away from the discs.
They don't bloody work, so I sacked them off to improve the initial bite on the brakes by reducing the amount of retraction, and while I was in there, got rid of the usual push-fit pins for the pads, and tapped the calipers to take some high tensile bolts instead in the same location - that way the bolts provide the same function, and also stiffen the bridge of the calipers when they're under load.
To stop the bolts being overtightened and distorting the caliper, and also let the pads slide smoothly on a low friction surface, I shrunk fit a bronze tube over the bolts to the right length to act as a dead stop:
Okay, it means you have to unscrew the bolts instead of just knocking two pins out to swap pads - but the pins are so famous for getting seized in on these brembos in various cars people even make plated aftermarket pins to solve it. So I don't think another 10 seconds is going to hurt vs beating out a stuck one.
It wasn't a huge difference but it reduced some of the pad knockoff I noticed they had on long high speed runs like motorway work.
They don't bloody work, so I sacked them off to improve the initial bite on the brakes by reducing the amount of retraction, and while I was in there, got rid of the usual push-fit pins for the pads, and tapped the calipers to take some high tensile bolts instead in the same location - that way the bolts provide the same function, and also stiffen the bridge of the calipers when they're under load.
To stop the bolts being overtightened and distorting the caliper, and also let the pads slide smoothly on a low friction surface, I shrunk fit a bronze tube over the bolts to the right length to act as a dead stop:
Okay, it means you have to unscrew the bolts instead of just knocking two pins out to swap pads - but the pins are so famous for getting seized in on these brembos in various cars people even make plated aftermarket pins to solve it. So I don't think another 10 seconds is going to hurt vs beating out a stuck one.
It wasn't a huge difference but it reduced some of the pad knockoff I noticed they had on long high speed runs like motorway work.
Edited by PhillipM on Thursday 16th February 17:07
shalmaneser said:
Do these help with the squealing at all? it always seems odd to me that some monoblock calipers suffer from this and others don't, even from the same company. I guess it's all to do with different resonant frequencies. Presumably you are still running retention springs?
No springs, I did try some coil springs on the bolts to see if it made a difference, but nothing. I think it's more the pad compound itself and the resonant frequency of the pads and caliper.It was probably a little quieter, or rather didn't happen quite as often with it setup like this rather than with the spring clips - but not a huge difference.
I do a little more with the calipers down the line but I'll leave that for the writeup.
There's more to come, I'm just trying to find old snaps/pictures. I really didn't take many for most of the work I did on this one as I wasn't intending on doing too much to it originally...that and trying to remember which order I did things in.
Edited by PhillipM on Saturday 18th February 12:34
Okay, a few of the immediate things I had with the car, even after that initial work - there was a knocking from the front and rear anti roll bar links. And then a front one snapped in two going down a gravel track, so it was time to get them sorted out.
They'd been replaced right before I bought the car at the MOT, but it turns out the garage fitted the cheapest, nastiest Starline ARB links they could get (never buy anything starline, they're the cheapest of the cheap bottom of the barrel garbage).
The previous owner was pretty nice and actually offered to nip with me to the garage to get them changed again under the warranty, but it would have cost me more in time and fuel than just fitting replacements, so out came the jack again, and I bought some high-quality Lemforder links to replace them with (I love Lemforder parts, tbfh, they're OE quality generally).
Now the front links are easy, but the rear links are an absolute pain - they're buried right in the middle of the multilink arms so you have to unbolt all sorts of stuff to get them off, especially if the nut just spins on the balljoint as usual with removing them.
And since I was already pulling parts off I decided to take a good look at the other bushes and rear brakes, etc, since the handbrake was pretty bad.
The discs/drums were pretty bad and the handbrake shoes were even worse:
Missing sections and the adjusters were pretty crusty, so I replaced and repaired all of that, gave the backplates a rub down and a coat of paint and fitted new handbrake shoes, new pads, new discs and rebuilt the rear calipers with new pad fitting clips and pins for good measure.
Now the rear droplinks were actually in good condition unlike the fronts, but I soon found the issue after removing things - the actual rear ARB bushes were shot:
These are a complete pain to get off as one side is buried at the side of the fuel tank and almost inaccessible, I ended up taking the rear trailing arm suspension links and bushes/mounts off to get that out as the bolts were seized...although the bushes there looked pretty tired too:
So if they're off already....
...may as well treat those to some new bushes too.
The rear ARB bushes were a bit of a pain, as sourcing parts for these cars can be a nightmare - the V6 Coupe has a larger rear ARB than the rest of the range, and despite that most sellers will still send you the smaller bush as fitting because they don't realise and someone got all the their cross-reference part numbers lumped in together at some point, it took me nearly 2 weeks to get the right sized bush after some serious hours scouring around.
As you can see in the picture above, the metal brackets were shot too, and these are also a part that's no longer available and a common part to corrode away, buried by the fuel tank as they are, they get coated in road grime and never washed.
I thought I had a picture somewhere but I guess not - anyway after searching for a while and finding many owners in the same spot with no replacements, I gave up trying to find a good pair of brackets, took a mould from the old one using a couple of layers of fibreglass, cut out some 2mm thick steel and then hammered out a new bracket into shape, using the fibreglass mould to shrink and tuck all the lips until I had a perfect replica.
After refitting everything there I moved into the cabin and the stereo - there was only output on a couple of speakers, it sounded terrible and there were some occasional popping noises turning it on and off, I assumed a few loose connections as it has an aftermarket headunit fitted, but it turns out to be a little worse - the 406 has a JBL amplifier fitted that does all the splitting to tweeters, etc, itself - however, despite using ISO plugs, it's wired completely differently. And it takes line-level inputs, not the high voltage output from a normal headunit.
Previous owner had just plugged an aftermarket headunit in and left it at that, so only 2 speaker outputs were connected, the volume was insane, the earths weren't connected and because there was no DC isolation between the headunit and the amplifier, turning the car on and off sometimes led to the banging and popping.
Anyway, I disconnected it, traced the wiring, bought a few ISO speaker connectors which I then rewired into an adaptor that turned the 406 pins into a standard ISO pinout, along with a quick prototype circuitboard between them that converted the high voltage output from the headunit into a low level signal for the amplifier, along with DC blocking through capacitors, a bleed down circuit to stop the popping noise and earthed the cable shielding to get rid of any hum or random noises.
I was happy that worked, but it lost some of the bottom end - my DC blocking circuit was also taking out the lower bass frequencies, so I cut it down into a much smaller version and added some bigger caps:
That worked fine so I then rebuilt the whole thing a third time into the neater, more compact version you can see on the top there, which I then printed a case for so it clips behind the dashboard/stereo out of the way:
Also treated it to an oil change and new air and cabin filters - it did have a pipercross foam filter on it which sounded lovely but also got massive heatsoak in traffic and also meant the idle air wasn't filtered as it goes through a seperate pipe, so I sacked that off, refitted the stock airbox and bought new OE filters. The cabin filter was definately overdue...
They'd been replaced right before I bought the car at the MOT, but it turns out the garage fitted the cheapest, nastiest Starline ARB links they could get (never buy anything starline, they're the cheapest of the cheap bottom of the barrel garbage).
The previous owner was pretty nice and actually offered to nip with me to the garage to get them changed again under the warranty, but it would have cost me more in time and fuel than just fitting replacements, so out came the jack again, and I bought some high-quality Lemforder links to replace them with (I love Lemforder parts, tbfh, they're OE quality generally).
Now the front links are easy, but the rear links are an absolute pain - they're buried right in the middle of the multilink arms so you have to unbolt all sorts of stuff to get them off, especially if the nut just spins on the balljoint as usual with removing them.
And since I was already pulling parts off I decided to take a good look at the other bushes and rear brakes, etc, since the handbrake was pretty bad.
The discs/drums were pretty bad and the handbrake shoes were even worse:
Missing sections and the adjusters were pretty crusty, so I replaced and repaired all of that, gave the backplates a rub down and a coat of paint and fitted new handbrake shoes, new pads, new discs and rebuilt the rear calipers with new pad fitting clips and pins for good measure.
Now the rear droplinks were actually in good condition unlike the fronts, but I soon found the issue after removing things - the actual rear ARB bushes were shot:
These are a complete pain to get off as one side is buried at the side of the fuel tank and almost inaccessible, I ended up taking the rear trailing arm suspension links and bushes/mounts off to get that out as the bolts were seized...although the bushes there looked pretty tired too:
So if they're off already....
...may as well treat those to some new bushes too.
The rear ARB bushes were a bit of a pain, as sourcing parts for these cars can be a nightmare - the V6 Coupe has a larger rear ARB than the rest of the range, and despite that most sellers will still send you the smaller bush as fitting because they don't realise and someone got all the their cross-reference part numbers lumped in together at some point, it took me nearly 2 weeks to get the right sized bush after some serious hours scouring around.
As you can see in the picture above, the metal brackets were shot too, and these are also a part that's no longer available and a common part to corrode away, buried by the fuel tank as they are, they get coated in road grime and never washed.
I thought I had a picture somewhere but I guess not - anyway after searching for a while and finding many owners in the same spot with no replacements, I gave up trying to find a good pair of brackets, took a mould from the old one using a couple of layers of fibreglass, cut out some 2mm thick steel and then hammered out a new bracket into shape, using the fibreglass mould to shrink and tuck all the lips until I had a perfect replica.
After refitting everything there I moved into the cabin and the stereo - there was only output on a couple of speakers, it sounded terrible and there were some occasional popping noises turning it on and off, I assumed a few loose connections as it has an aftermarket headunit fitted, but it turns out to be a little worse - the 406 has a JBL amplifier fitted that does all the splitting to tweeters, etc, itself - however, despite using ISO plugs, it's wired completely differently. And it takes line-level inputs, not the high voltage output from a normal headunit.
Previous owner had just plugged an aftermarket headunit in and left it at that, so only 2 speaker outputs were connected, the volume was insane, the earths weren't connected and because there was no DC isolation between the headunit and the amplifier, turning the car on and off sometimes led to the banging and popping.
Anyway, I disconnected it, traced the wiring, bought a few ISO speaker connectors which I then rewired into an adaptor that turned the 406 pins into a standard ISO pinout, along with a quick prototype circuitboard between them that converted the high voltage output from the headunit into a low level signal for the amplifier, along with DC blocking through capacitors, a bleed down circuit to stop the popping noise and earthed the cable shielding to get rid of any hum or random noises.
I was happy that worked, but it lost some of the bottom end - my DC blocking circuit was also taking out the lower bass frequencies, so I cut it down into a much smaller version and added some bigger caps:
That worked fine so I then rebuilt the whole thing a third time into the neater, more compact version you can see on the top there, which I then printed a case for so it clips behind the dashboard/stereo out of the way:
Also treated it to an oil change and new air and cabin filters - it did have a pipercross foam filter on it which sounded lovely but also got massive heatsoak in traffic and also meant the idle air wasn't filtered as it goes through a seperate pipe, so I sacked that off, refitted the stock airbox and bought new OE filters. The cabin filter was definately overdue...
Edited by PhillipM on Tuesday 21st February 18:20
At the moment, nothing
I'm out of work following an eye injury and some ops that lasted the last two years, and trying to find somewhere to get back to work before I run outta money
Before that I generally did prototype and small batch (100-1000) parts for track and race cars, damper rebuilds/valving, fabrication, welding, rollcages etc.
I still have the wavy discs! I saved them from the 306, those and the steering wheel.
I'm out of work following an eye injury and some ops that lasted the last two years, and trying to find somewhere to get back to work before I run outta money
Before that I generally did prototype and small batch (100-1000) parts for track and race cars, damper rebuilds/valving, fabrication, welding, rollcages etc.
I still have the wavy discs! I saved them from the 306, those and the steering wheel.
Stick Legs said:
Lovely.
I remember chasing through traffic on the M6 once convinced I had spotted a pale blue Ferrari 456, got closer & it was one of these.
I was a RWD snob in my youth and ignored these. Which was foolish.
Beautiful & stylish.
The cabin is very, very similar to some Ferrari silhouttes, hence the F360 replica kits using 406 coupes.I remember chasing through traffic on the M6 once convinced I had spotted a pale blue Ferrari 456, got closer & it was one of these.
I was a RWD snob in my youth and ignored these. Which was foolish.
Beautiful & stylish.
Interestingly some of the ancillaries are pin compatible with Ferrari parts too - I guess that was Pininfarini building them there - in fact I swapped a few parts for Ferrari ones when I couldn't get replacements as I'll show later.
Edited by PhillipM on Tuesday 21st February 18:52
PhillipM said:
At the moment, nothing
I'm out of work following an eye injury and some ops that lasted the last two years, and trying to find somewhere to get back to work before I run outta money
Before that I generally did prototype and small batch (100-1000) parts for track and race cars, damper rebuilds/valving, fabrication, welding, rollcages etc.
I still have the wavy discs! I saved them from the 306, those and the steering wheel.
I saw you'd had issues with your eye in the buggy thread... Hadn't realised it was so bad. Glad it's sorted. I'm out of work following an eye injury and some ops that lasted the last two years, and trying to find somewhere to get back to work before I run outta money
Before that I generally did prototype and small batch (100-1000) parts for track and race cars, damper rebuilds/valving, fabrication, welding, rollcages etc.
I still have the wavy discs! I saved them from the 306, those and the steering wheel.
Your previous job does explain how you're able to build stuff like the buggy. Good luck with the job hunting!
Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff