After an accident my front right wishbones got bent
(visibly) and the torsion bar has about a 10 degree bend in it.
A local E-type restorer told me they might be able to fix
them by heating them and bending them back into shape.
To be quite honest I’m not sure if this is the way to go.
The wishbones are pretty darn expensive to buy new, but a
wishbone is a part you really don’t want to fail when you
hit a pothole at 100 mph…
What do you think? Repair or replace?–
1964 Series 1 3.8 FHC
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Lucas sent Tue 24 Jan 2012:
Replace. The wishbones are forged and the TBs are heat treated
steel alloy. You can’t help but affect the metalurgy by getting
them hot enough to straighten, unless whoever is doing it is a
wizard. There must be lots of used spares avaialable. That’s where
I’d go without giving it a second thought.–
1968 E-type OTS since 1982, 1954 XK120SE OTS since 1991
Ontario, Canada
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Lucas sent Tue 24 Jan 2012:
Replace without question in my opinion.
Dave–
The original message included these comments:
After an accident my front right wishbones got bent
(visibly) and the torsion bar has about a 10 degree bend in it.
A local E-type restorer told me they might be able to fix
them by heating them and bending them back into shape.
To be quite honest I’m not sure if this is the way to go.
The wishbones are pretty darn expensive to buy new, but a
wishbone is a part you really don’t want to fail when you
hit a pothole at 100 mph…
What do you think? Repair or replace?
–
'61 OTS
Pershore, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Lucas sent Tue 24 Jan 2012:
I expect you probably could straighten the control arms, but
I wouldn’t recommend it. As for straightening the torsion
bars? No doubt you could make it straight again, but no
frickin’ way would it ever work right when you were done.–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
My driveway is long enough that you can appreciate the conflict between the desire for privacy and the terror of being completely lost .----- Original Message -----
From: “Lucas” lavdhouten@planet.nl
To: e-type@jag-lovers.org
Sent: Tuesday, January 24, 2012 1:18:53 PM
Subject: [E-Type] Repairing bent wishbones & torsion bar
Hey guys,
After an accident my front right wishbones got bent
(visibly) and the …
In reply to a message from Lucas sent Tue 24 Jan 2012:
As an E Type Restorer I straighten wishbones all the time. But do
not do cold. Torsion bars can also be straightend using a heating
torch, not a welding one, but will require re heat treating as the
temper will be altered with the heating process.
I would advise having both bars re temperd at the same time or it
may be a good time to put in some uprated bars from a S2 car, or
even after market ones.–
The original message included these comments:
A local E-type restorer told me they might be able to fix
them by heating them and bending them back into shape.
–
850225/679,1E21003,2W2001BW,JNAEY3AC100218,SAJNV4841KC156072
HEIDELBERG HEIGHTS, Australia
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Lucas sent Tue 24 Jan 2012:
Replace. The wishbones are forged and the TBs are heat treated
steel alloy. You can’t help but affect the metallurgy by getting
them hot enough to straighten, unless whoever is doing it is a
wizard.
Heating metal to soften it affects the properties permanently unless you
know how to harden them to their original strength.
Lately I have been fabricating some wire baskets using 5/16 ths 6061
aluminum rod which is work hardened by stretching it after extrusion.
I found that heating it to 775 F and letting it cool makes it as pliable
as 1100 aluminum.
There is a great deal of art and science in softening metal to make it
pliable.
You really don’t want to take chances with your safety.
George Cohn
'70 OTSOn 1/24/2012 2:28 PM, Nickolas S. wrote:
I second that, this is no place for short cuts and torsion bars aren’t
even expensive. I seriously doubt they could be cost effectively
salvaged. Most of the usuals have used parts but I personally
wouldn’t bother with a used torsion bar.
pauls 67ots
In reply to a message from Lucas sent Tue 24 Jan 2012:
Replace without question in my opinion.
Dave
<<<<<<<From: “Dave K” david@kerr2209.fsnet.co.uk
Subject: Re: [E-Type] Repairing bent wishbones & torsion bar
G’Day Lucas,
Depending on “how much” bending is needed to straighten it a wishbone will
proportionately fatigue in the bend area and be more likely to fail under
stress. Heating it will introduce localised stress points in the crystal
structure of the metal that could lead to unpredictable cracking failure.
So… unless it is a relatively small bend easily straightened ‘cold’ in a
press I would replace it (your life, you choose - a bit like the Dirty Harry
quote “Do you feel lucky…”). Applying localised heat to help straighten
a torsion bar will always, without exception irreparably damage a torsion
bar (or any other spring for that matter). After straightening this way it
will sag within a few miles, when you go to the trouble of re-setting ride
height it will again sag within a few miles, after several more iterations
it will eventually sag/twist enough to fracture at place you applied the
heat (probably at a most inconvenient time/location). If you can find a
‘real’ tradesman springsmith the torsion bar can be repaired by:-
heating whole bar evenly to bright whiteish red and straightening by
rolling under pressure on a (large enough) flat steel block
reheating evenly till bright whiteish red again and quenching in oil
(quenching oil is very similar to diesel fuel or home heating oil which can
be used in a pinch)
reheating till just hot enough to cause sparks if the hickory handle of a
hammer etc is rubbed along the bar (get it too hot or cool unevenly and you
have to start again)
cool it slowly and evenly down to room temperature
shot peen it (use a sand blasting cabinet to fire small leads or iron at
it all over)
scragg it (twist it in a heavy lathe in the normal working direction to
15% more than its maximum installed working range in the car about 10 times)
I am absolutely certain any local mechanic with a gas axe would not be able
to do this anywhere within a bull’s roar of good enough, would not have flat
steel slab, temp controlled furnace, surface flat roller to straighten bar
without putting hammer marks in surface, tank of quenching oil, peening
cabinet, scragging lathe, oh… did I mention skill? I am just as certain
buying a new one is going to be “much” cheaper than finding someone with the
skills and equipment to do this right.
gets bar straight
hardens the spring steel (makes it springy)
& 4. temper the steel (remove internal stresses caused by quenching)
removes surface scale and micro cracks which could propagate to a full
crack
gives the spring a ‘set’ (appropriate to side it is to be installed so it
does not sag when installed - left and right bars are scragged in opposite
directions of course)
Cheers, John B. 67 2+2 in Oz______________________________________________________
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Sounds easy enough.
Seriously John,
Thanks for that, very interesting, clear and informative.
Alan----- Original Message -----
From: “john bennett” jembennett@westnet.com.au
To: e-type@jag-lovers.org
Sent: Wednesday, January 25, 2012 5:26 AM
Subject: [E-Type] Repairing bent wishbones & torsion bar
G’Day Lucas,
Depending on “how much” bending is needed to straighten it a wishbone will
proportionately fatigue in the bend area and be more likely to fail under
stress. Heating it will introduce localised stress points in the crystal
structure of the metal that could lead to unpredictable cracking failure.
So… unless it is a relatively small bend easily straightened ‘cold’ in
a press I would replace it (your life, you choose - a bit like the Dirty
Harry quote “Do you feel lucky…”). Applying localised heat to help
straighten a torsion bar will always, without exception irreparably damage
a torsion bar (or any other spring for that matter). After straightening
this way it will sag within a few miles, when you go to the trouble of
re-setting ride height it will again sag within a few miles, after several
more iterations it will eventually sag/twist enough to fracture at place
you applied the heat (probably at a most inconvenient time/location). If
you can find a ‘real’ tradesman springsmith the torsion bar can be
repaired by:-
heating whole bar evenly to bright whiteish red and straightening by
rolling under pressure on a (large enough) flat steel block
reheating evenly till bright whiteish red again and quenching in oil
(quenching oil is very similar to diesel fuel or home heating oil which
can be used in a pinch)
reheating till just hot enough to cause sparks if the hickory handle of
a hammer etc is rubbed along the bar (get it too hot or cool unevenly and
you have to start again)
cool it slowly and evenly down to room temperature
shot peen it (use a sand blasting cabinet to fire small leads or iron
at it all over)
scragg it (twist it in a heavy lathe in the normal working direction to
15% more than its maximum installed working range in the car about 10
times)
I am absolutely certain any local mechanic with a gas axe would not be
able to do this anywhere within a bull’s roar of good enough, would not
have flat steel slab, temp controlled furnace, surface flat roller to
straighten bar without putting hammer marks in surface, tank of quenching
oil, peening cabinet, scragging lathe, oh… did I mention skill? I am
just as certain buying a new one is going to be “much” cheaper than
finding someone with the skills and equipment to do this right.
gets bar straight
hardens the spring steel (makes it springy)
& 4. temper the steel (remove internal stresses caused by quenching)
removes surface scale and micro cracks which could propagate to a full
crack
gives the spring a ‘set’ (appropriate to side it is to be installed so
it does not sag when installed - left and right bars are scragged in
opposite directions of course)
Cheers, John B. 67 2+2 in Oz
In reply to a message from Lucas sent Tue 24 Jan 2012:
Can it be done? Sure can. Are you exactly sure of, and capable
of, understanding the metallurgy, techniques, and temeprature
control needed to do so? No’t sure.
If not, it isn’t worth any cost savings. I know how, but I still
would just replace the stuff.–
The original message included these comments:
After an accident my front right wishbones got bent
(visibly) and the torsion bar has about a 10 degree bend in it.
A local E-type restorer told me they might be able to fix
them by heating them and bending them back into shape.
What do you think? Repair or replace?
–
Paul Wigton, steward to a '60 DKW 1000 SP, Tweety, '63 FHC!
Keenesburg, CO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from john bennett sent Wed 25 Jan 2012:
I knew you’d shed your considerable twisty insights into the
spring part!
I watched this done once at a local spring shop (had to repair a
torsion bar off a 1923 firetruck: NOT available at Bunnings…)
and came away with a MUCH greater appreciation–and understanding–
of the mysteries of springs!–
The original message included these comments:
heating whole bar evenly to bright whiteish red and straightening by
rolling under pressure on a (large enough) flat steel block
reheating evenly till bright whiteish red again and quenching in oil
(quenching oil is very similar to diesel fuel or home heating oil which can
be used in a pinch)
reheating till just hot enough to cause sparks if the hickory handle of a
hammer etc is rubbed along the bar (get it too hot or cool unevenly and you
have to start again)
cool it slowly and evenly down to room temperature
shot peen it (use a sand blasting cabinet to fire small leads or iron at
it all over)
–
Paul Wigton, steward to a '60 DKW 1000 SP, Tweety, '63 FHC!
Keenesburg, CO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Lucas sent Wed 25 Jan 2012:
Torsion bars, no way. Wishbones? Yes way. I straightened one in my
current car and have another I will straighten at some point for
another car. No massive bends but it is a mmassive section part
over-engineered to cope with every conceivable load in use. Job
done.
I did it ‘by eye’ laying the fixed one alongside a good one and
over-corrected a tad before bringing it back. Any fractional sub-
millimetre deviation is a total non-issue, as everything gets
adjusted in situ when you do the geometry set-up. I was thinking of
going to one of the local farriers to get the job done but since I
had access to the farmer’s massive floor-mounted vice a few feet
away from my own press, plus access to big scaffolding pipe, it was
a quick job.
But TBs? No point, as the tnecessary reatment affects the primary
function of tha part, as has been said.
Pete–
1E75339 66 D, 1E33100 66 FHC, 1R7977 69 OTS, 1R9720 69OTS
Cambridge, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Ray Livingston sent Tue 24 Jan 2012:
A torsion bar buy any other name is a SPRING and springs are reset
and reheat treated by spring manufacturers for a variety of reasons
such as lowering or raising the car to original height due to
spring sag over many years.–
The original message included these comments:
bars? No doubt you could make it straight again, but no
frickin’ way would it ever work right when you were done.
–
850225/679,1E21003,2W2001BW,JNAEY3AC100218,SAJNV4841KC156072
HEIDELBERG HEIGHTS, Australia
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–