Scraped Undercarriage

Mark Roberts · Post by **Mark Roberts** » Tue Apr 30, 2002 1:40 pm

I got a WOF yesterday - 10 years old, 120 on the clock, no problems,
good eh?

But anyway - I took a look at the underneath. I have a somewhat
abusive relationship with my jellybean and I drive on forest roads
fairly often. What a mess - the entire length of the two "chassis"
rails is badly crumpled. Not to mention a gaping hole in the
floorplate in between! (not big enough to prevent WOF)

The mechanic says he has seen this before and he recommends getting a
substantial steel strip welded to the bottom of the two rails. That
way you can carry on regrading dirt roads and it will take the bumps
with less damage.

Thought I'd pass it on...

Mathew · Post by **Mathew** » Tue Apr 30, 2002 1:47 pm

My 91 is exactly the same. My car hadn't been in the country long when I got it, and as the damage looked quite fresh I assumed it was done loading and unloading the vehicle off the boat from Japan. They don't look very strong at all which is probably why it is not used as a jacking point.

Biff [Paradise 2] · Post by **Biff [Paradise 2]** » Tue Apr 30, 2002 2:04 pm

Hi all,
I had mine up off all 4's recently and didn't notice any damage but was
wondering, has anyone looked (built) an aerodynamic package (ventury)
for the underside?
On looking it would seem a possibility, its nice and clean underneath ?
Biff

From badcat@xtra.co.nz Fri Apr 27 16:12:43 2007
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Subject: Re: Scraped Undercarriage
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Yep - mine too.
Anyone on the list want the job of reinforcing our underbellies?
Maybe done right we could add some more rigidity...
I'm keen to be guinea pig..
K

\
On 30/4/02 1:47 PM, "Mathew" <matt@deepvideo.com> wrote:

[...]

Delich, Martin · Post by **Delich, Martin** » Tue Apr 30, 2002 2:45 pm

Be cautious of what welding is carried out on the chassis of your car(s).
Caution also needs to be exercised with regard to who does the welding and
what technique they use.
Due to the more common use of high tensile steel in production car chassis'
care must be taken to ensure the specific welding doesn't actually weaken
the structure (un-heat-treat the steel). The reinforcing may look good from
the outside but you could end up with a weakened structure.
MD.

Gary Morrison · Post by **Gary Morrison** » Tue Apr 30, 2002 2:56 pm

My 91 import was like this too when I bought it. Those box sections are part
of the rigidity of the chassis, but they won't take too much pressure
without crumpling. I was told that the cars are forklifted off and on the
ships and that is how the damage occurs.

Any of you with NZ new cars like to look underneath and see what yours look
like? The rails are rectangular box sections that run lengthwise on either
side inboard of the side sills.

You have to watch out when anyone is jacking your car up. I've stopped tyre
guys and mechanics who've rolled the jack under and gone for those rails.

Gary

Ray · Post by **Ray** » Tue Apr 30, 2002 3:24 pm

My 91 NZ car which i've had from new still has a perfect undercarriage, but then its
only done 23k and has never ever been driven in the rain or on the dirt,
Gary is quite correct in stopping people from jacking them up on the box sections
they will crumple very easily, and just to put members minds at rest they also have
a stronger floorpan than a new falcon or holden, obviously because they are a convertible,
and while we are on mechanics, make sure the wof guys dont shut your bonnet with
their elbows just because they have greasy hands, they dent real easy because as
you know they're ali. wof man dented my neibours in this manner and once ali stretches
your cannot get the dent out.
Ray

[...]

Mark Roberts · Post by **Mark Roberts** » Tue Apr 30, 2002 3:43 pm

are a convertible, and while we are on mechanics, make sure the wof
guys dont shut your bonnet with their elbows just because they have
greasy hands, they dent real easy because as you know they're ali.

Yeah and if you have the habit of going to sporting or other events
where your mates perch their backsides on your car while they chat
with you, make sure they don't sit on the headlights 8^(

Mike Donovan · Post by **Mike Donovan** » Tue Apr 30, 2002 6:40 pm

My '90 import had a bit of crushing in one end of the rails, same place both
sides. The garage failed a warrent yet 2 panel beaters told me he was being
over the top because they are not a part of the chasis but only floor
stiffeners. In the end I had to get the seats removed and the floor cut open
from the inside and have them beaten back into shape then the floor
rewelded. So you guys who have dings the rails and are still able to pass
a warrent are onto a good thing.

Mike

Mark Roberts · Post by **Mark Roberts** » Tue Apr 30, 2002 7:01 pm

me he was being over the top because they are not a part of the
chasis but only floor stiffeners.

Most modern cars are monocoques, whose stiffness is created by their
rooves. MX5s don't got rooves. Dey only got floors. MX5s are
sportscars requiring megastiff undercarriage so it's even more
important that they be stiff... Dem strut thingies underneath, plus
some other stuff eg the door sills, are what give you the grippy
skippy ride you like so much...

Post by **zorruno** » Tue Apr 30, 2002 10:31 pm

my 94 has steel strips welded beside the box section lengthwise along the
full length. This was there when imported and was a mounting location for a
roll cage. I'll try and get pics sometime.

if the box section wasn't damaged before - I'm sure it will be now after the
Northern mystery run in the weekend... 100mm road clearance... 120mm judder
bars

Yep - mine too.
Anyone on the list want the job of reinforcing our underbellies?
Maybe done right we could add some more rigidity...
I'm keen to be guinea pig..
K

My 91 is exactly the same. My car hadn't been in the country long when I

got

it, and as the damage looked quite fresh I assumed it was done loading and
unloading the vehicle off the boat from Japan. They don't look very

strong at
[...]

Bill Rehm · Post by **Bill Rehm** » Thu May 02, 2002 7:06 am

I had a "over zealous' examiner once fail my puddle jumper due to one of
the these rails being dented/crushed somewhat from driving over a high
driveway curb. I received all sorts of ridiculous quotes (i.e. expensive)
to replace the rail. In the end I found someone who was able to somehow
make it look OK for a few bucks. So be aware you can be failed for your WOF
because of this.
Bill Ream

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