Welding/drilling to chassi

[Wambat]

hey fellas

as the title suggests i was wondering about welding and drilling on the chassi of a 4wd. say for instance like a 60 series land cruiser.

if you were putting sliders on, and you didnt want to use the u clamp and bolt technique, if you drilled the chassi where you want to possition the flange bolts, drill the chassi out and put crush tubes in to stop the chassi bending in, is that the prefered way to do that tupe of job.

also if drilling the chassi if on the inside side of the rails you welded a 6mm plate with the same holes as the flanges to give it a bit more strength, and used deccent tensile bolts, would that work well???

what about on the back, say if at the back of a 60 with a cab chop, if you cut the chassi back at the spring hanger?? if you then boxed that off and welded a new bit in across the gap.

how do the enginners take to that? as if i am mistaken some one please let me know. but i am pretty sure that the chassi is not plain mild steel but tougher?? more carbon content or something, so welding mild steel could be the problem?? or is it just a matter of after welding heat treatment like heating it up after and letting it all cool at the same time, or pre heating the weld area to make sure you get the best penetratin you can, or to stop the sudden heat from doing unwanted things like weakening the mettal(like what happens in cromoly isnt treated right after its been welded) i know it wouldnt be the same as cromoly but i am asking,

i am a pretty good welder, i have enough faith in my skills to be able to compleat the work i want to do, but havent yet under taken the welding courses that i want to(will be signing up to them from next years classes hopefully, they get so packed) so pre heating metal is stuff i ahve picked up of of the boilermakers i have worked with(i am a fitter and have a fair bit of experiance ont he job, however i have alot to learn), but we were talking about thick steel her, that would just absorb all the heat, and i am pretty sure tuffened steel as the machine we were talking about was a brick extruder, and most of it was made so that it was hard wearing, however the part being welded when that modification was happening did not see the clay being pushed through, it was where the internal rig(thats what they called the rings that were a type of chrome alloy steel that was hard wearing)

sorry for being so long winded, but id appreciate if some one out there could shed some light on what the engineers would say to welding and bolting through the chassi with crush tubes..........

did a serch got a few hits but nothing that mentioned engineers??

thanks fellas

Alistair

[hammey]

what state are you in?

I know i nsw you can. all i did was ring the rta technical hotline and asked them.

smitty

[Wambat]

victoria

[ajsr]

have a look on the rta web site it may well you there in the mods section.
its a good read anyway not that anything ive done complies

[bigbluemav]

Not to be rude, but WHY would you do that unless it was ABSOLUTELY necessary?

For rock sliders you can make up a 3 sided 'U' clamp with the bolt at the top! Why would you drill it (weaken it) or weld it (weaken it and enable the start of rust inside the chassis?

[Wambat]

cause i dont like the u clamp idea, i know its been tryed and tested, but i am thinking about something that might possibly be better.

and if you use crush tubes, that are welded back into the chassis, then do the appropriate heat treatment, it should be stronger.

[HANCOCK]

As you said tried and tested works a treat (U) why not stick with something that works drilling and welding the chassis is a last resort and will not be as strong as a well set up U channel around it with out the extra stress??? Mine are 80 X 12 M/steel flat bar and don't budge. If it welded It would need to be engineered....

[bigbluemav]

As you said tried and tested works a treat (U) why not stick with something that works drilling and welding the chassis is a last resort and will not be as strong as a well set up U channel around it with out the extra stress??? Mine are 80 X 12 M/steel flat bar and don't budge. If it welded It would need to be engineered....

Again, not to be rude, but WHY? Do you plan on dropping it out of a plane onto one of the rock sliders/sidesteps? They only have to flex up a little and they hit the sills anyway. Unnecessary engineering/drama to the max!!

Why go through the drama? And what are you going to do to the INNER portions of the chassis to prevent rust to the now expose bare metal of the CHASSIS?

I know its your car, but you seriously can't write to a forum like this ands ask advice on a third rate idea and not expect to get sh*t. I'm surprised you haven't been flamed out of existence

Everyone must be getting more polite (or older like me!!).

[V8Patrol]

Basically......

welding is a huge NO NO

drilling is accepted but only in the web section of the chassis rails
(may require a engineers report is some cases)

drilling the flanges of the chassis rails will require a trip to the engineers.


Contact VicRoads for more info

Kingy

[Toyo80]

what state are you in?

I know i nsw you can. all i did was ring the rta technical hotline and asked them.

smitty

As long as you do not weld onto the flanges of the chassis.

[Wambat]

ok so i got the answers i was looking for so thanks for that.

why should i be flamed out of existance, for wanting a techinacl reason for why not to, not just cause its what you got and they havent budged, thats a fine reason yes. but its not to say there isnt a better way to go about it, i may be wrong, as at this point i am not going to say i think i am wrong cause i dont, and you could very well be some one who knows better and more than i, however, your response dosent make me think you do, and im not trying to starts something thats going to end in a whole lot of name calling and bitching and moaning,

i just wanted to know the technical reasons why, like i have drilled my chassi before to add a bull bar, and i know that the steel was harder than mild as the drill was blunted, but that being said i dont know what type of steel it is, i am sure i could find out though. and i have seen people welding in sections to box off parts of thier chassi and i wanted to know what the go is so i can strengthan certain parts, and so that as i have proken leaf spring hangers inthe past i can either add new ones or make plates to strengthan the old ones.

so now you guys are telling me it weakens the chassis and that i shouldnt, ok fine no problem, i could live with u clamps thats fine, but it does give me other questions, like then how do you go about mounting a tray to a former wagon bodyed chassi??? as at sme point you will have to weld some where, ither to place a plate that can be bolted to or what not, and for the roll bars....


i am asking questions so that when it comes time to do the job, and put the truck on the road i am not driving around in a death trap

[bigbluemav]

Dude

That's all fine and good. From a lay person's perspective (I'm not an engineer or fabricator like some guys on here). Drilling holes/welding on the front (or rear) of the chassis is fine, compared to welding/drilling in the MIDDLE where the stress is. Welding also destroys (burns off) the paint on the INSIDE of the chassis and leaves that surface open to rust easier that if it had the paint that WAS on it.

A good welder will have the right technique, equipment, knowledge and consumables to do the job properly. For you and me to fire up a welder and throw together some sliders is great, but to start attaching 5mm mounting plates to chassis that may be less than 2mm thick is NOT cool.

Most of the situations re: welding the chassis (mouting tray etc.), from my observations is/can be largely unnecessary if a little more thought is put into it. Just look at how they do it on comp vehicles and in mags and in forums like these. Be open what people suggest. The best part about forums is that you can save HEAPS of dramas because no matter how good you think your idea is, invariably it has been done before. That is the BEST part of internet forums!!

As I said, I'm no fabricator, but I listen to those who are. Best way to learn good sh*t and save heaps of drama and $$$$.

[blade 929]

[quote="bigbluemav"]Dude

That's all fine and good. From a lay person's perspective (I'm not an engineer or fabricator like some guys on here). Drilling holes/welding on the front (or rear) of the chassis is fine, compared to welding/drilling in the MIDDLE where the stress is. Welding also destroys (burns off) the paint on the INSIDE of the chassis and leaves that surface open to rust easier that if it had the paint that WAS on it.

A good welder will have the right technique, equipment, knowledge and consumables to do the job properly. For you and me to fire up a welder and throw together some sliders is great, but to start attaching 5mm mounting plates to chassis that may be less than 2mm thick is NOT cool.



chezzy racing sliders required plates to be welded onto your chassis

[Wambat]

i am sort of in the know though (am a fitter and turner with a fair bit of fabrication experiance and as a side note to that i am actualy seriously considering doing another wpperntice ship as a boiler maker so that i can learn this properly and do it for my self and others and open my own fabrication place)but i still have a heap to learn that is why i am asking questins about it, and as the last boiler maker i worked with was telling me about box section steel, he was saying it is better when welding rhs at right angles ( |--- ) <---- like that) to each other to use a plate, that is longer (so if you use 50x50 mm rhs, use a 150mmx50x3) plate as the rhs is cold rolled and has some stress (this is where my knowlege starts to gt thin)

i have alot of pictures on my home computer with tray, roll bar, roll cage(i have a better idea about mounting them as ive seen a few circuit race car cages in the construction process) to give me ideas and to refer too. but they still leave me with questions, like the ones i have asked.

i am hugely open to what people suggest, and as we have just heard(if blade is correct) some professionaly built sliders need plates welded in.

there would be a way to coat the inside of the chassis to stop rust, i just dont know what they would be yet.

[bazzle]

Dude





chezzy racing sliders required plates to be welded onto your chassis

Doesnt mean it was road legal.

Top bolt idea or even large U bolts are tried and proven (and easy)

Bazzle

[hammey]

what state are you in?

I know i nsw you can. all i did was ring the rta technical hotline and asked them.

smitty

As long as you do not weld onto the flanges of the chassis.

just wondering what you mean by the flange?

examples.

superior long arm mounts
hyd bump stop mounts
roll cage mounts
rear ute cage mounts
coil over mounts
re-engineered body mounts
shock hoop mounts
weld in drop boxes
and no doubt many more.

All fairly integral to a cars safety, strength and reliability and all welded to the chassis.

my sliders are welded on with 100mm wide by 150mm high 10mm thick plate seam welded and fully engineered in NSW.

My point is, of course you can do it. However, with regards to legality that will be sorted with a couple of phone calls to the relevent state authorities.

cheers smitty

[Wambat]

smitty, that is exactly how, and the lines i have been thinking along, however, i would prefer to ask here to see if any one has gone through and done, or asked the right people the questions i want to know first, i figured if i had a good idea before i rang the engineer up, i could have fabbed up some replicas of what i want to do,

buy that i mean gotten a length of box section that closely resembles the chassis(100x75 or 100x50 what ever the dimensions of the chassis is), do what i want to do to my 4wd with that, when he sees what i am talking about he can tell me exactly what the pros and cons, and legalitys are, and if i have it wrong how to make it right,

my idea may be over engineered, but i would find comfort in knowing i could drop my car out of a plane onto the sliders and they not bend at all. and the way i am thinking, the more wight lower down really cant hurt the truck.

[shakes]

Something to also think of is what's going to break first. Your amazingly re-inforced sliders, or will you twist and f^&k out your chassis because thats now the weak link??

[hammey]

Fair comment shakes.
All the factors must be considered when doing any modification.
Thats why i often give my engineer or the rta a quick call before i try something outthere to get a professionals perspective.

Your from Vic Wambat, my best advice to you would be to go along to one of the engel series and have a look at what these guys are doing to their comp rigs for reliability sakes.

also dont waste your time making mockups, just call up the engineer and tell him what you want to do and why. He's an accredited eng. he'll say yes/no or tell you what he wants to see.

cheers smitty

[Wambat]

shakes - one of my mates brought me up on that earlier, as yes that was a point i was over looking, and i also thought that, the little it of chassis flex that we would all get to a degree would also then be null and void which might be beneficial.

hammey - only reason i was thinking about making a mock up, is i some times done explain myself the best, so to some one like an engineer you don't want to come across as a dimwit, so if i made what i was talking about i would have a visual aid to help me look like less of a retard.

however i have seen everybody's point with the clamps and with them they wouldn't be a major modification to the structure of the car so no engineering??? as no one has actually stated that, if they are not welded to the body,


also something i havent noticed with any of the photos with the u clamps, i have seen some that are welded, in annother recent thread there is a couple.

but what about having them bent up?? does the bending effect it adversely (as ive been told like with roll cages) that cold bending is the only way to go(with cages) as the heat changes the metal and the cold bend is stronger(and there for safer) is it the same with slider clamps? or can you heat them and bend, or plates welded together(which in my opinion would be much the same as heating and bending for putting heat stress into the steel)

and what thickness do people use? ive seen some that could look like its 6 mm, but that looks too small. but is 12mm to large? espcialy if your having it bent up.???

[Slunnie]

Thats probably the case more so with Cro-mo etc cages. Mild steel cages aren't really affected by heating - there isn't enough carbon in the steel to worry it.

Most bending work like that is done cold just because its cheap and easy.

With the slider I personally would just cold bend it unless you cant bend it cold - in that case add heat.

[Wambat]

i was pretty sure it was meant to be done cold, however i am not 100% so ill leave it at that till some one tells me better.

[Slunnie]

i was pretty sure it was meant to be done cold, however i am not 100% so ill leave it at that till some one tells me better.

If its just steel then it doesn't make a lot of difference if you cold bend it, hot bend it or weld it. Plain regular mild steel isn't heat treatable. If you do bend it, just bend it once though and not backwards and forwards while trying to get it right - that will weaken it. Mind you it gets bolted across the top anyway.

[hammey]

One way i use to create tight radius 90degree bends in mild steel is to cut half way through the flat bar/plate along the opposite line of the bend with a 1mm cutting disc.
I then bend it in the vice, turn the mig up and weld the crack up leaving it proud

Application is a big determining factor when using this method though, but it works way easier and the bend radius is way tighter than just oxy alone.

cheers smitty

[Wambat]

cheers guys, will keep all in mind when it comes time.

[Mick.]

Hey Wambat this is confirmation on what is legal in NSW. I'm sure Vic roads would have the same rules about welding to a chassis. Welding across the top or bottom of the chassis rails (flanges) is illegal period. I'd also recommend that any other welding to the chassis be done with Silicone bronze for best results by a Body builder not a boiler maker as there 2 totally different trades. As you can see though drilling the chassis and putting crush tubes in, even welding them in is fine.

Just make sure you check your own rules and regulations first though.

http://www.rta.nsw.gov.au/registration/ ... v_2007.pdf


As for coating the inside of the chassis with something to stop the rust the only thing you can do is shove a heap of rust proofing up there when your done.

Cheers Mick.

[HTH]

anyone want to post a pic of the chassis rock slide mounts
""3 sided 'U' clamp with the bolt at the top""

[v840]

anyone want to post a pic of the chassis rock slide mounts
""3 sided 'U' clamp with the bolt at the top""

http://outerlimits4x4.com/ftopic170383.php

Have a search dude. Heaps of pics on here of this and likely every other set-up you want to see.

[Toyo80]

what state are you in?

I know i nsw you can. all i did was ring the rta technical hotline and asked them.

smitty

As long as you do not weld onto the flanges of the chassis.

just wondering what you mean by the flange?

examples.

superior long arm mounts
hyd bump stop mounts
roll cage mounts
rear ute cage mounts
coil over mounts
re-engineered body mounts
shock hoop mounts
weld in drop boxes
and no doubt many more.

All fairly integral to a cars safety, strength and reliability and all welded to the chassis.

my sliders are welded on with 100mm wide by 150mm high 10mm thick plate seam welded and fully engineered in NSW.

My point is, of course you can do it. However, with regards to legality that will be sorted with a couple of phone calls to the relevent state authorities.

cheers smitty

Well in nsw you can weld onto the side of the chassis providing it is not at the top or bottom (flange) it must be welded to the side of the chassis.

We are talking side steps/sliders are we not?

The info is available on the RTA nsw website within the guidelines for light vehciles.

[stokedapollo]

wouldnt having them bolted with the big u and bolt be better if they got damaged than being welded to chassis
cut or unbolt them off and put new ones on
if they are welded you have to grint /oxy /plasma etc ??
correct me if im wrong but to me undoing a bolt seems better to me