thunderace
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| posted on 12/12/09 at 12:20 PM |
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can you turn leaf springs upside down
can you turn leaf springs upside down
i want to lower my transit mk6 fwd im thinking od cutting 2 coils from the front and fliping over the rear leaf springs ,but will it work?
has anyone done this sort of thing before ?
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britishtrident
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| posted on 12/12/09 at 12:25 PM |
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You can't just flip the spring over but You can turn over one or two of the smaller leafs but this will make the spring a lot softer which
isn't what you want when you lower a vehicle
Normal way is to make lowering blocks and use longer u bolts.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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StrikerChris
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| posted on 12/12/09 at 12:34 PM |
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i wouldn't chop your coils either.dont know if you can buy lowering springs for it but if you can it'll be £50 well spent and you'll
be able to get an mot and possibly blag the insurance when you whack someone.not a chance with cut off springs!
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pewe
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| posted on 12/12/09 at 12:58 PM |
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What BT says ^^.
Normally lowering blocks are machined ali. but the old fashioned (cheapest and easiest) way was to use well-seasoned oak or similar hardwood.
Cheers, Pewe 
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snapper
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| posted on 12/12/09 at 12:59 PM |
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Escort Boys use lowering blocks between spring and axle this effectively pushes the axle up.
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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ali f27
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| posted on 12/12/09 at 01:09 PM |
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leaf spring
leyland did it with the herald was absolutly crap has to work transvesly fiat did it with strada worked perfectly
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thunderace
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| posted on 12/12/09 at 02:00 PM |
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it only has 1 leaf spring in the rear and if you cut 2 coils of the front would it not make the front shocks harder and as for the mot i cant see why
it would fail?
remember the transit it made to carry weight and i wont be useing to carry anything other than me the mrs and my dog.
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thunderace
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| posted on 12/12/09 at 02:01 PM |
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quote:
Originally posted by snapper
Escort Boys use lowering blocks between spring and axle this effectively pushes the axle up.
i did that with my mk2 escort.
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prawnabie
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| posted on 12/12/09 at 02:17 PM |
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Surely it would fail the MOT for incomplete road springs?
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nick205
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| posted on 12/12/09 at 02:31 PM |
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DO NOT cut coil springs and drive it on the road please. Coil springs are wound to a close at each end and then cut properly square or sat on a
profiled seat so they're properly supported. Hacking the end off means they'll never sit square, wont work as intended and pose a risk of
coming unseated or snapping.
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liam.mccaffrey
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| posted on 12/12/09 at 02:33 PM |
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didn't PPC do a feature on DIY spring cutting? I don't remember but it would be interesting to see if they included some kind of
disclaimer.
Build Blog
Build Photo Album
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thunderace
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| posted on 12/12/09 at 02:47 PM |
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quote:
Originally posted by liam.mccaffrey
didn't PPC do a feature on DIY spring cutting? I don't remember but it would be interesting to see if they included some kind of
disclaimer.
chopshop do it on there cars ???
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zilspeed
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| posted on 12/12/09 at 03:15 PM |
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quote:
Originally posted by thunderace
quote:
Originally posted by liam.mccaffrey
didn't PPC do a feature on DIY spring cutting? I don't remember but it would be interesting to see if they included some kind of
disclaimer.
chopshop do it on there cars ???
Yes.
And it's pretty much on a par with the rest of the "engineering" on display on the rest of the show.
Remember, this is the programme where he exended a gear lever by something like 600mm then wondered why it had a longer throw...
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britishtrident
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| posted on 12/12/09 at 04:00 PM |
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quote:
Originally posted by ali f27
leyland did it with the herald was absolutly crap has to work transvesly fiat did it with strada worked perfectly
Except the Triumph Herald had transverse leaf spring.
Heralds handing problems were due to the use of a very crude swing axle.
On the Mk4 Spitfire Triumph turned one of the leafs on the rear spring upside down to soften the rear roll stiffness, lower the car and give the rear
some negative camber, result much improved handing.
Stradas/Ritmos did handle well the only good thing about them but it was nothing to do with the transverse leaf spring.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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MikeCapon
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| posted on 12/12/09 at 04:02 PM |
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Chopping springs is perfectly safe when, as with most things, it's done right.
Most mass production car spring seats are not flat enabling them to support a spring that has not been closed and ground flat like you normally see on
a seven or a motorcycle.
You should make sure that the spring is parallel or when you chop it the diameter will not suit the spring seat. Also check what spring rate
you'll end up at. For each live coil you remove you will up the spring rate by the percentage of coil(s) removed. Original no of live
coils/coils removed*100 = %age increase.
I'll attach a spring rate calculator to the end of this post. In general it works OK as lower car needs higher spring rate.
If you need to change the shape of the end of the spring after chopping I'd look for a set of springs ready-made for the job. The spring needs
to be heated and then ground which is a tricky job if you've not done it before. Also the amount of work involved begins to exceed whatever
saving you might make.
As for whether it is an acceptable practice, I know for a fact that an importer for a certain Swedish make of shock (Ô) does this when he has not got
the spring he needs in stock.
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Steve G
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| posted on 12/12/09 at 04:13 PM |
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quote:
Originally posted by thunderace
chopshop do it on there cars ???
Thats it - you've convinced me........... i'll never cut a spring on any vehicle.... ever ever.
As said - its a verrrry bad idea.
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MikeCapon
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| posted on 12/12/09 at 06:04 PM |
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quote:
Originally posted by Steve G
Thats it - you've convinced me........... i'll never cut a spring on any vehicle.... ever ever.
As said - its a verrrry bad idea.
Er.. Can you explain why please? It sounds to me very like those people who tell you you can't build your own car...
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dodgedartgt
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| posted on 12/12/09 at 07:39 PM |
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I don't about european Ford Transit, but if it is like most american vans, the axle sits under the spring. Just flip the axle to the top of the
spring by either moving the spring perches 180 degrees or welding on a second set to the bottom of the tubes. Also consider having the leafs rearched
to a flatter profile.
As far as cutting the springs, in the states it is a very common practice. Most vehicles don't have the ends ground flat like typically found on
narrow coil-over springs. You are more likely to find that the end of the spring is "clocked" into the spring seat pocket, or even not at
all. Just take this into account when cutting.
Do not cut with a torch, you will ruin the temper of the spring. Instead, use an abrasive cut-off wheel. Be careful not to shorten a spring so much
that at full suspension travel it can become disengaged from the spring pocket and/or mount (think MGB with the rear axle limiting straps).
I worked for an aftermarket performance suspension component manufacturer. One of the products we sold were muscle car application specific lowering
springs. Some were custom wound, most were new, modified, OEM springs.
When you shorten a spring, you are increasing its rate. In a lowered car, you generally want a higher rate due to less distance to bump stops (a good
case for dropped spindles).
The company owner was a mechanical engineer / gearhead. All this was done correctly, using spring calculator (coil diameter, wire diameter, number of
coils, free height, etc...) and then followed up on a hydraulic or pnuematic test rig (force / distance compressed = rate, ie, 1000# / 2" =
500#in springs)
In other words, not cutting coil springs is a bunch of hooey. Just like anything, there is a right way and a wrong way to do it.
Mike Bynum
SW Florida
(Edited spelling mistake.)
[Edited on 12/12/2009 by dodgedartgt]
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mark chandler
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| posted on 12/12/09 at 07:51 PM |
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I have chopped springs without issue, if you knock 1/8th off it will becoem 1/8th stiffer as above.
If I was to do this on a macphearson strut I would carefully grind the platform welds and lower by moving this down and rewelding then purchase a
strut insert as you will fry the shock bit.
Axle as above also, if it sits below the spring move above, in my experience most UK cars are above anyway so lowering blocks or do what the stock car
racers do and play a gas torch over the leaf spring with the car loaded, it will then sag to a new curvature.
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MikeRJ
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| posted on 13/12/09 at 12:24 AM |
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quote:
Originally posted by MikeCapon
Chopping springs is perfectly safe when, as with most things, it's done right.
Most mass production car spring seats are not flat enabling them to support a spring that has not been closed and ground flat like you normally see on
a seven or a motorcycle.
They don't have flat seats, but they are designed to seat a spring where the last turn of the coil is as flat as possible (i.e. effectively coil
bound). Sticking a chopped spring into these means nearly all the weight is supported by one point of the seat.
Sorry but it's a bodge whichever way you look at it.
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gazza285
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| posted on 13/12/09 at 01:59 AM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by MikeCapon
Chopping springs is perfectly safe when, as with most things, it's done right.
Most mass production car spring seats are not flat enabling them to support a spring that has not been closed and ground flat like you normally see on
a seven or a motorcycle.
They don't have flat seats, but they are designed to seat a spring where the last turn of the coil is as flat as possible (i.e. effectively coil
bound). Sticking a chopped spring into these means nearly all the weight is supported by one point of the seat.
Sorry but it's a bodge whichever way you look at it.
Surely you would just turn the top mount round until the spring was seated into the end of the seat? I had a spring break on my van, I jacked the van
up, reseated the spring by turning the top mount (and using a large pry bar to help the spring up) and carried on. Did about four months before I
could be bothered to change it, passed its test with the short spring on as well, only changed it when the top mount seized completely, which was the
cause of the spring breaking in the first place.
DO NOT PUT ON KNOB OR BOLLOCKS!
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MikeRJ
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| posted on 13/12/09 at 10:13 AM |
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quote:
Originally posted by gazza285
Surely you would just turn the top mount round until the spring was seated into the end of the seat?
The point is it will never be correctly seated since the spring seat is not designed to hold the end of the chopped spring.
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Brommers
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| posted on 13/12/09 at 11:04 AM |
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quote:
Originally posted by MikeRJ
They don't have flat seats, but they are designed to seat a spring where the last turn of the coil is as flat as possible (i.e. effectively coil
bound). Sticking a chopped spring into these means nearly all the weight is supported by one point of the seat.
Sorry but it's a bodge whichever way you look at it.
Er, not in my experience. For example this Macpherson strut
doesn't have a flat lower coil or a 'nearly coilbound' lower coil. It's the same length coil to coil throughout and the
spring seat is angled to compensate. In my experience of MacPherson struts that's the norm, since it's easier to press a bit of tin to
make an angled spring seat than it is to make a spring with a flat base.
If the spring does have a flat base, and the spring seat is flat or flatish as a result then yes, it's a bad idea to cut the springs. However,
if the spring seat is like the one shown above then I still can't see the problem with it, notwithstanding all those claiming it's
strictly verboten in all circumstances.
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brianthemagical
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| posted on 13/12/09 at 12:20 PM |
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I'm pretty sure Transit springs are of the modified end type, i.e, mot just a chopped coil. If that is the case then it should fail it's
MOT. The springs are also something like 1000lb/", so chopping any resonable amount off it will make it a bit stiff.
As with anything, do it if you want, or at least whip off the spring and see what it looks like, maybe add some pics.
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gazza285
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| posted on 13/12/09 at 02:07 PM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by gazza285
Surely you would just turn the top mount round until the spring was seated into the end of the seat?
The point is it will never be correctly seated since the spring seat is not designed to hold the end of the chopped spring.
As per Brommers picture.
Flat at the top for the swivel, open at the bottom to sit on the strut.
DO NOT PUT ON KNOB OR BOLLOCKS!
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