Patrol 4x4 - Nissan Patrol Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
152 Posts
Discussion Starter #1
Hi Guys,

Been searching through the forum for a plan of Rock Sliders Chassis Bracket that I saw a few months ago. Thought I'd saved to my HDD, but can't find it anywhere.

It was a drawing of just the Chassis Mounting bracket that someone had done for their own rock sliders. It seems to have disappeared, anyone know which thread it is in so I can print a copy?

Thanks
GU42gold :confused:
 

·
Registered
Joined
·
152 Posts
Discussion Starter #2
anyone??
 

·
Registered
nissan
Joined
·
8,930 Posts
Nice of someone to make a drawing. I believe there is a flaw in it though, the u section used between the top of the main |_| will have to be quite tall to give sufficient material on the top of the bolts to prevent them tearing through. with a 5mm thickness (Id want thicker), then a M10 bolt then, 10mm of material above that, with then a 5mm gap between the top of this and the actual body. thats 30mm clearance needed, where the front mount normally goes there is about 17-18mm between the top of the chassis rail and the body.

Personally I do not like bolt on sliders though. Welded tapped plates for the main two mounts on the chassis are much stronger. They will also not crush the chassis rail between the main U section.
 

·
Registered
Joined
·
152 Posts
Discussion Starter #6
Benno,

Quite true regarding clearances. After finding the plans, I continued to read the associated thread from which it came. It turns out that Twistys truck has a body lift so he has the required clearances. He also didn't put the "Extra" U plate at the top as he found it wasn't required.

For me it was mainly the fact that I'd seen the drawing and was after ideas on construction of my own sliders. As I don't have a body lift (Can't due to airbag) I'll look at a different version I've come across for the U bracket, actually more like a C bracket.
I believe welding onto the chassis in NSW is not legal, hence if true, welding plates to chassis is not an option.

Currently I have TJM bush bars and the rear bracket is held in place by a threaded rod, which after landing a couple of rocks at The Springs Park last year, twisted backwards and upwards, so definiately not strong enough.
 

·
BORDERTREK 4X4 & FABRICATION
Joined
·
8,549 Posts
I believe welding onto the chassis in NSW is not legal, hence if true, welding plates to chassis is not an option.
It's not true in any state. Otherwise repairers etc would not be allowed to repair cracked chassis's. Any welding done on a light vehicle chassis must be done to industry standards though.
Cheezy Racing welded plates onto chassis for the sliders he made and sold and were legal. Different story with heavy vehicle chassis though (4500kg +), some cannot legally or safely be welded at all.
 

·
Registered
nissan
Joined
·
8,930 Posts
What Sudso said is true, the truck chassis are HSLA (high strength low alloy) steel that is extremely weakened from the weld heat, most vechiles (the patrol definately is) use slightly varying mild steel. In the patrols case its just bloody C channels!

Macquarie 4x4 also do weld on sliders.

Ill quite readily back these over clamps :)

 

·
Registered
nissan
Joined
·
11,121 Posts
im thinking of redoing my slider mounts like this. as it seems alot stronger and also easier to get on and off.
though what thread pitch would you guys reccomend for it. ie m14x1.5 or go to a national coarse thread of some sort?
 

·
BORDERTREK 4X4 & FABRICATION
Joined
·
8,549 Posts
What Sudso said is true, the truck chassis are HSLA (high strength low alloy) steel that is extremely weakened from the weld heat, most vechiles (the patrol definately is) use slightly varying mild steel. In the patrols case its just bloody C channels!
Pretty much all ladder chassis 4wd's are just two pressed c channels joined together to form a box section and welded together.
A bit of common sense needs to be used if mounting sliders to welded plates on the chassis though. If you landed hard enough on a rock etc it could tear the welded plate from the thin chassis and the chassis material is subject to fatigue after welding too, especially from persistent vibrations or corrugations etc. The plates welded to the chassis in that pic is wrong too, it should be a fish plate not welded vertically straight down across the section. Even though I'm a welder my preference is still bolt on.
 

·
Registered
nissan
Joined
·
8,930 Posts
Are you saying that they should not be welded vertically?

Macquarie 4x4 is one of the big name brands that weld vertically.

By fishplates do you mean that the plate should be off the chassis, like instead use C channel?
 

·
Registered
Joined
·
668 Posts
hmm interesting reading. Although I havnt gotten it done yet mine are likely to be welded. I was talking to my engineer about it he seems to think the best option will be a combo of bolts/ weld. His plan is to weld on a plate onto the chasis which will hang lower so he can then bolt onto it. Will talk to him more about it tomorrow, gotta ring him anyway and hurry him up..
 

·
Sabbath Keeper
nissan patrol
Joined
·
209 Posts
Pretty much all ladder chassis 4wd's are just two pressed c channels joined together to form a box section and welded together.
A bit of common sense needs to be used if mounting sliders to welded plates on the chassis though. If you landed hard enough on a rock etc it could tear the welded plate from the thin chassis and the chassis material is subject to fatigue after welding too, especially from persistent vibrations or corrugations etc. The plates welded to the chassis in that pic is wrong too, it should be a fish plate not welded vertically straight down across the section. Even though I'm a welder my preference is still bolt on.
Yeah... what do you mean by fish plate?
 

·
Registered
nissan
Joined
·
4,831 Posts
I made my steps/sliders/scrub bar brackets clamp style like drawings, used 10mm plate and 2x12mm bolts, would only be about 1-2mm clearance from chassis for bolts 3 points of chassis and no body lift, good enough to jack ute from, but I guess time will tell
 

·
BORDERTREK 4X4 & FABRICATION
Joined
·
8,549 Posts
Are you saying that they should not be welded vertically?
In general any welds shouldn't travel across or down the cross section of a load bearing part of a structure (the chassis in this case) eg: This is why you dont (or shouldn't) see welds across the top of trailer draw bars where they join to the trailer frame.
A fish plate is more like a diamond shape so the welds are going more with the longitudal length of the structure <__> but more commonly used when butting sections together that aren't sleeved.
I haven't heard of any sliders tearing the welded brackets out of the chassis as yet (not to say it hasn't happened but I have seen a couple of dodgy back yard ones with cracked brackets etc) but I still prefer the full bolt on method for rock sliders as they have a bit of give especially when hit hard and also makes it easier for the guy at home to fit.
What makes it hard for wrap around bolt on brackets on many 4by's is the lack of clearance between the chassis and floor on non body lifted rigs for a decent amount of "meat" above the bolt holes in the brackets. My Rodeo was no different so I had the bolts vertical instead (2 HT bolts per bracket x 3 brackets per side) with the bolts just long enough for nylocs to fully grip the threads but still clear the body.


 

·
Registered
nissan
Joined
·
8,930 Posts
I know what fishplates are in the railways, and they are much the same as the plates on mine, but you mean fish shaped. It was a monday and I had a late shift ;)

I understand why you dont weld across the top of trailer and this is explicity a no no as this is weakening an area in a direct line where a crack can start and then run around the chassis. Welding as above wont give a crack a place to start. In the RTA document it deliberately points out the top and bottom of the C section but not the side.

I have seen the <> fishplate mentioned before and I think its the worst of them all. 80% of the stress will be sitting right on the V at the bottom. IMHO it will open like a can, peeling the chassis out in a V if it gets a decent crack. In welding |_| it is pushing over the chassis (and pulling in a direct line across the bottom) and the only way it can tear is tearing the welds underneath holding the two C sections together. Nissan have also welded vertically all over the chassis. Also this <> or even <=> plates will compromise the bolt positions too, so you would more than likely be forced to a go to a - : - pattern, which puts unduly loads the bottom bolt.

I was always under the impression that the <> plate is mainly to be used in situations in which it is under a longditudional tension, in which it is a very strong join compared to butt welding where >> butt welding was impracticle.
 

·
Registered
Joined
·
1 Posts
I know what fishplates are in the railways, and they are much the same as the plates on mine, but you mean fish shaped. It was a monday and I had a late shift ;)

I understand why you dont weld across the top of trailer and this is explicity a no no as this is weakening an area in a direct line where a crack can start and then run around the chassis. Welding as above wont give a crack a place to start. In the RTA document it deliberately points out the top and bottom of the C section but not the side.

I have seen the <> fishplate mentioned before and I think its the worst of them all. 80% of the stress will be sitting right on the V at the bottom. IMHO it will open like a can, peeling the chassis out in a V if it gets a decent crack. In welding |_| it is pushing over the chassis (and pulling in a direct line across the bottom) and the only way it can tear is tearing the welds underneath holding the two C sections together. Nissan have also welded vertically all over the chassis. Also this <> or even <=> plates will compromise the bolt positions too, so you would more than likely be forced to a go to a - : - pattern, which puts unduly loads the bottom bolt.

I was always under the impression that the <> plate is mainly to be used in situations in which it is under a longditudional tension, in which it is a very strong join compared to butt welding where >> butt welding was impracticle.
I gotta disagree with this. Vertical welds introduce a shearing possibility which is far more likely to crack than a tension stress mainly because the majority of the introduced stress on the chassis is from the weight of the car bouncing up and down. Better off welding the horizontals instead where practicable.

Also a fishplate isn't traditionally sharp edged. the diamond shape is a general shape description and they should either have run off welded edges or rounded edges depending.
 
1 - 20 of 21 Posts
Top