Chassis Lamination

[JJBigWheels]

Hi Guys,

I have just purchased a GQ comp truck and have found a couple of chassis issues. One is at the front on the inside of the steering box, which I know can be helped by adding the Nissan recall kit - is there any other sugestions? Also have a full weld cracked on the inside passenger side just behind the transfer at a join. I think it is simply a matter of grinding out and welding but some advice would be appreciated.

I have also noted that a few comp trucks around mention that they have a fully laminated chassis? I assume this is just an extra plate welded the length of the chassis but some advice as to wheather this is a worth while addition and some photos/description as to how you have done it would be appreciated.

Would appreciate any opinions and help guys. Cheers

[MikeH]

google: Fish plates weld (include the weld so you don't get a bunch of crockery for serving marine creatures)

I wouldn't laminate a whole GQ chassis, they are one of the strongest out there apart from the spot where yours has cracked.

I would laminate the inside of the chassis on the drivers side where the panhard and the steering box hang off and go back to where the chassis fattens near the brake lines.
The simplest way is to make a template from cardboard that is a few mm too small, then trace it onto plate with a plasma cutter. To save it being stupidly heavy put a series of holes along it about 40mm diameter and weld inside the holes. the front and back ends should not be vertical, instead make them pointed with 45 or even 60 degree angles, so spread that concentrated stress of the end of the plate along the chassis. thats where the name fish plate comes from... the point can be wither inward or outward.


where your crack is at the back, grind and weld, then it might be wise to plate over it with a smaller fish plate... they can look like this: <====> or like this >=====> (see, fishy....) whatever you do dont go like this |=====| because it will crack at the vertical bits..


Full chassis lamination is for those who have a welding fetish, no girlfriend and are too stubborn to admit they started with the wrong vehicle to build a comp truck.

[toughnut]

What MikeH said. But to give you a visual image of what you can do here is a couple of links to build threads on here that show you what we're talking about.

This is a much different application but it still has some pics at the bottom of this page that shows you how Heath has laminated the Chassis near the steering box.
http://www.outerlimits4x4.com/viewtopic ... U&start=60

This one is Kents build up of his class 8 truck. A little closer to what you are probably looking at and it has some pics of how he has strengthened his chassis.
http://www.outerlimits4x4.com/viewtopic ... 6&t=197122

The best thing you can do is to actually have a look through some build threads and see what they have done.

Cheers
Steve

[JJBigWheels]

Thanks for the replies guys. I am glad that no one seems to think laminating the whole chassis is necessary as it was not a job I was looking forward to attempting if everyone thought it was worthwhile. I have done a hell of a lot of reading on this and other forums before getting in to the comp stuff!!

I have done a lot of fish plating when building heavy pig trailers for trucks and just thought I would put across some thoughts on installing them. IMHO and experience a fish plate should never be fully welded and should never continue on the angled piece to end in a point. There should always be a straight perpendicular edge not a point and this should not be welded. The weld along the angled part of the plate should continue past the plate and this will help prevent cracking by allowing minor unoticable flex which will help prevent fatigue of the weld causing cracking.

I have a few photos which I took today of fish plates on our 19tonne pig trailer which I would like to post up as a photo says a million words but I am not a "contributing" member yet. Can someone please possibly volunteer to post up the IMG link if I PM them with it. I would certainly appreciate other opinions on my theory as always keep an open mind

Cheers

[JJBigWheels]

By the way Toughnut I love your work on the GQ/U middy mate. Mine is a MWB GQ with an 'A' frame extension but I like your triangulated system better. I saw your post regarding the Brake Bias on your thread, I have one of these on mine and would be happy to put up some pics when I can. Also happy to email you some photos if you would like.

To be honest I dont think it makes a big difference but I havn't pushed my rigs performance that far yet, I am waiting until I am a bit more used to it. Let me know if you would like some photos

[Tiny]

You can host images elsewhere and link :-)

[JJBigWheels]

Thanks Tiny! I thought I could not link things yet but I will give it a go.

Here are the photos which probably explain it better -






I hope that everyone can see what I mean??

[unmass]

Awesome pic of fish plate, can anyone provide some pics of the fish plating required on the chassis. As I'm bracing my diffs and may aswell strengthen the chassis too.

Regards
Mitch

[turps]

That spot on the inside of the rails behind the 3 body mount are plated with the most shitty welding ever on GQ utes. But was never done on wagons, must have thought the body would hold it together. It is a join in the chassi and is prone to cracking. My wagon has a crack developing on one side. So am going to grind it out and then plate it. Want be a huge plate though.

[JJBigWheels]

Awesome pic of fish plate, can anyone provide some pics of the fish plating required on the chassis. As I'm bracing my diffs and may aswell strengthen the chassis too.

Cheers Mitch yeah I am lucky we have a cnc plasma which makes making these types of things to suit really easy. I have a plan on how I think it should be done but just wanted to get some thoughts from the guys who have done this before. I will get some photos of pre and post modification. I was going to use the factory recall upgrade on the steering box but I think I might do something myself.

That spot on the inside of the rails behind the 3 body mount are plated with the most shitty welding ever on GQ utes. But was never done on wagons, must have thought the body would hold it together. It is a join in the chassi and is prone to cracking. My wagon has a crack developing on one side. So am going to grind it out and then plate it. Want be a huge plate though

Thats the one turps......glad its not just mine was begining to think I've bought a Lemon LOL. No just kidding I'm really happy with my rig just a couple of issues like this to have a play with which is what its all about. Would love to see what you do with the plating mate, post up some pics pre and post if you can. Glad you caught it early my weld is fully cracked and the underside of Chassis has started as well. I'll get some pics up soon.