Reinforcing chassis

[stinger]

Hi just like to know if anyone can put me onto someone in Victoria,that they may know who does this kind of work welding a steel plate the same shape onto the chassis bend area ,Im told its the best way to strengthen the chassis or your thoughts on the matter would be appreciated thanks.

[NowForThe5th]

Why?

The way I see it, the way the chassis bends in the ML/MN Triton is something that is designed in. If you plate that area, preventing flex, then you're just going to transfer the load to somewhere else that isn't designed to take it.

If you're concerned about the chassis bending/breaking then the conditions under which this happens are fairly well established and are, in general, avoidable. There re numerous examples, with pictures, in this thread of reinforcing plates having failed or having caused failure elsewhere.

If your application/intended use is one which is likely to result in chassis failure then, if it were me, I'd be seriously considering whether there may be other vehicles out there, i.e. not dual cab utes, that might be more suitable for the application.

[4wd26]

http://www.newtriton.net/phpbb/viewtopic.php?f=18&t=12629&hilit=bent+chassis&start=225#p428607

Ive been speaking to my mechanic and he reckons he could weld some plates either side of the chassis rail in very tempted to do this. Any thoughts on this lads n lasses?

Have a look at those photos of the Tritons with the camper bodies on the back. They were plated. Still bent.

They bend on a different place to most others, they bend along the weld where they welded an extended mount.
I would be very cautious about doing this. As far as I know it illegal to weld chassis, so if anything did happen you would be left holding the bent baby, so to speak. Also you don't know what effect it would have, and where it may transfer load to. I had an engineer look at mine (a mate) and he suggest the same homers solution, bracing it using the tray. Not much help for tubs tho.

I still stand by them. I'm yet to hear of one bending with out air bags. I have big loads on mine when doing extended trips and given it a bit of work out. I would be at the standard gvm for weekend trips and pushing close to my new gvm of 3300 for extended trips. Don't know how much the tray helps, but touch wood had no problems. Towing to the max over rough terrains would make me nervous.

[bodia]

I have seen some of the hire camper mobs have been plating the chassis on tritons with the big campers on the back so maybe try them. On another note its actually a bit weird plating the sides but not the top and bottom of the chassis. In I beam design the web (vertical section) is only there to separate the flanges (horizontal sections)at a consistent distance. The strength comes from the flanges not the web. To make a stronger section you either separate the flanges further or increase the strength of the flanges. Plating the top and bottom of the chassis will have a much larger effect than adding plate to the vertical part of the chassis.

[Kegsy]

On a vehicle chassis, plating the top and bottom does absolutely squat, waste of time. Unless of course you have done a cut and shut to replace a damaged rail section.

Strength will come from fish plating the sides of the rails. The trick with the triton is knowing where to begin the plate, where to finish it and how it should be installed.

Nearly every fish-plated triton chassis I've seen on here has been wrong; most of which have been a poor addition after the bending moment.

There was one really well designed plate, but they only did one side of the chassis which was a little weird but overall was a really good addition.

IMHO plating of the MN chassis if towing off-road is a very worth while modification. I was going to do mine, but I ended up moving to the jeep before I started the job.

[4wd26]

kegsy

please explain why not to do the top and bottom

I know but for clarity if you could use your experience in this topic then the forum as a whole will benefit.



thanks

[dougie123]

I've been told by a boiler maker that welding a chassis will weaken it because of the metal treatment they use to harden the chassis. Next time I see him I'll for more info.

[Kegsy]

When I said it does squat, it actually does strengthen the rail but usually not for the better...

Long story short, it (plating the top and bottom plates) will create a zone where the chassis is much stiffer in a small section resulting in the load being transferred to the ends of the plated section. Good chance the frame will crack in this location if the point of termination is chosen poorly. However if the top and bottom sections of the rail are previously damaged, you have no choice but to plate them.

The top and bottom plates are the main strength of the chassis and as such need to be treated with caution, there are very specific things you can and can't do, a lot of the restrictions are around the welding of this surface.

Fish plating the sides allows extra strength, but enough forgiveness and installation flexibility to ensure that load isn't pushed off somewhere else in the chassis resulting in failure (when done correctly). This is your best option if you just need to add strength to prevent a failure.

[Kegsy]

I've been told by a boiler maker that welding a chassis will weaken it because of the metal treatment they use to harden the chassis. Next time I see him I'll for more info.

Common misconception.

Heavy vehicle chassis' (Prime movers etc) cannot be welded due to the above. Light vehicles with a ladder chassis it is completely safe and legal.

It is highly desirable to be very careful with heat input to the base metal (as with all welding) and to allow the welded area to cool as slowly as possible to retain as much strength as possible.

[L200Shogun]

Superior Chassis Repair Plate Mitsubishi Triton ML

[ag9111]

Just make sure you don't plate over the VIN No