Rusty Under carriage rails

[DreamZproject]

What is the best thing to do what you have rusty under carriage rails?

I'm not sure if this is the right name for it, but its the two rails that travel the farthest

towards the back of the car, ending roughly underneath where the seats are.

 

Is it possible/ a good idea to take these rails off, and put new ones on (where the hell

would i be bale to find these???), or is it better to simply de-rust the area, and get a

welder to patch in some plates and strengthen the area?

 

If this info is too convoluted ill take some pics tomorrow.

 

Thanks guys!

[Retro Z]

Is your floor rusted too?

 

I replaced my floors and used 2.5mm walled 1"x4" boxed primed steel and cut,bent, welded from the front to rear subframe connecter. Definatly helps with rigidity.

 

Otherwise you can get a metal shop to bend some sheet metal replacements for your rails.

 

I wouldnt bother patching your existing ones as its probably all rusted on the inside.

 

Post up some pics if you can

[potter260]

Hi, yeah i replaced my chasis rails with ones i made from 1.5 zinc sheet and got my panel beater to remove old ones and put the new ones in. But mine were crushed as well as rusty.

[Scoota G]

Those rails support the floorpan.

You can run them down to the back if you want to.

You can buy replacment rails with floorpans or, or take a sample to a steel fabrication/ sheetmetal business and have some fabricated.

It is less expensive to have some fabricated.

 

I just made a list

[DreamZproject]

hmmm rails to the back sounds tempting... im guessing that would stiffen up the chassis

quite substantially... I'm thinking that the floor-pan will need a good looking to as well, so

i think ill just take it along to a fabricator and see what they can do for me...

 

Thanks for the info guys! very helpful!

[Retro Z]

You should get Scoota or Lurch to do it for you since your in Melbourne.

 

My Chasis rails cost about $70 in steel and a day to cut, bend, grind, and weld and about $50 in gas and $10 in consumables eg grinding discs etc. So Scoota or Lurch should be able to do similar for not too much.

 

My chassis rails also are ladder framed ( rails going 90 degrees from the chassis rails). Helps so much with rigidity that when i jack up a corner the other corner lifts off the ground too.

 

I will put up some pics tomorrow to give you an idea. If you are handy with a hammer,grinder,pliers, vice its something you can make youself and get somebody to weld it up for you to reduce labour costs

[DreamZproject]

WOOOOH this is all great stuff here! yeah pics would be great! I'd definately be keen to

pay either scooter or Lurch to get it all done. I've been wanting someone to see my car

for a while so they can give their professional opinion on various aspects. This is the

perfect excuse!

 

I love AUS Z CAR

[Retro Z]

If you have facebook look up and like the page called:

 

"The midnight warrior " datsun 240z.

 

Lots of pics of Scoota G's repair work of Vivek's (Vramjee) 240z.

 

there is also another Facebook page called :

 

Classic auto fabrications.

 

Has some pics of Lurches repairs of Saxon's Z and some other cars.

[DAT392]

Haven't been on for a while as I have been super busy for 18mths with new business and no time for cars,but I would talk to scoota if I were you.He did some rust repairs on mine and the job was awesome.Glad this topic has come up as I am gonna find time and see if he can reinforce my rails and some other bits and pieces cause i might be adding a bit more power.cheers.

[nizm0zed]

Scoota or lurch (or anyone else that'd know)

 

Can the rail replacement be done on a complete running car?

Or does it need to be done on a stripped shell?

[PeterAllen]

..Can the rail replacement be done on a complete running car?

Or does it need to be done on a stripped shell?

It can certainly be done on a running car it is just that rotisserie builds nearly always take the opportunity to do it. Likewise there is the option to either replace the frame rails or the much simpler approach to attach another rail over the top of the existing rail.

 

If you look at the floor from inside the cabin you will see the spot welds holding the rails. If you want to replace the rails simply drill through the welds, if you wish to use covering rails just drill a series of holes in between the existing spot welds. You then use a trolley jack to hold the new rails up against the floor and you can weld them to the floor (from inside the cabin) through the holes which have been drilled.

 

You will have to get under the car and weld the ends or they will fill with water and start the rust all over again.

 

The new rails can be whatever gauge and depth you want.

 

I replaced the floors and added full length heavy gauge rails but these photos illustrate the way covering rails would work. I also used 'Fergusons' rust proofing and it was very easy to weld through - I got it from Supercheap.

[nizm0zed]

Excellent stuff!!!!

 

Very good to know.

[Scoota G]

I took a different approach to extending the chassis rails in my 2+2 project where i cut the bottom out of the old chassis rail where 95% of the rust was. I then took some box tube which i profiled to the floorpan and extended it to the rear.

[C.A.R.]

It can be done with the car jacked up on Axel stands, but it's a prick of a job doing it upside down.

 

On a 240Z/early260Z, Full new 1.6mm Zincseal rails from the front of the footwells back to up under boot floor crossmember, is around the $1000 mark fitted & painted, if the car in not on a rotisserie.

Add another $500 for a post '75 260Z or 2+2 as the rails are a PITA to make & fit...

 

Robbie - get a light under the car & take some photo's of the rails.

Pictures speak a thousand words

[DreamZproject]

Yeah, will do Lurch!

 

$1000??? is that what a mechanic would charge to do it, or what you would charge???

 

I am quite keen for the rails to extend all the way to the rear of the car because it really

shouldn't be too much more work than putting a regular one in.

[MaygZ]

It is my opinion, and I emphasise my opinion, that people get a bit excited about these rails.  It can be seen from their design, that they do not add any support or rigidity to the car.  They serve 2 purposes:  firstly they provide some extra strength to the floor (note the strength is provided to the FLOOR - to prevent a foot going through it as you step in and out); and secondly to provide some protection to the feet from objects that strike the underside.

 

It is my opinion that extending them to the back adds extra strength to the FLOOR and none to the chassis.  Using a heavier guage steel gives extra protection to your feet - for more weight.  I don't believe it adds any strength to the vehicle.

 

$1000 would go a long way towards a half cage - now that would help strengthen the chassis!

[PeterAllen]

In terms of a standard Z most of what MaygZ states I support and there is no need to go beyond the original design. However, it instances where a high torque drivetrain is being installed it would be prudent to optimise the strength of load bearing areas and fittings. The basic shell is designed to address suspension loads and dynamics whereas the frame rails cope with the engine torque and in my case, directly, the gearbox loads - they do a lot more than support the floor.

[DreamZproject]

Well here are some pics... as you can see, the underneath of the car has about a cm worth

of grease and dirt all over it, but you can see that the ends of both rails are rusted right the

way through. The on on the passenger side is actually rusted up through to the foot well.

 

Considering this, whats the best plan of action?

 

https://www.dropbox.com/s/fmqvobrppa45f3d/20120812_132603.jpg

https://www.dropbox.com/s/a9zx59xzold94od/20120812_132549.jpg

https://www.dropbox.com/s/l7i1q4d96mpycqy/20120812_132648.jpg

https://www.dropbox.com/s/d1479jhswtj60gm/20120812_144110.jpg

 

Lurch, if you were to do the work (i could help you in any way possible too) what would you

charge for a regular sized rail, and an extended rail?

[C.A.R.]

PM Sent.