Advice and opinion on triangulating rear chassis.

[Paul Y]

So looking to triangulate the rear part of the chassis on Woody.

I am not taking the cab off so would appreciate feedback on my rough mock up.





Would this work?

What gauge square tubing should I use?

Am I wasting my time?

Any and all comments welcome.

P.

[Paul Y]

Just realised that the rear most tape should probably terminate at the chassis rather than the crossmember.

Thoughts?

P.

[chevy_mike]

What are you trying to accomplish? If less twist, you really need to X brace the frame. The front area, from from your bed mount area diagonally across to the shock mount crossmember and then put an X bar across from the other side. Behind the shock mount crossmember, run one from there to the rear of the frame and then an X bar on the other side. You'll want to put a crossmember at the rear of the frame to tie the rear X bracing together.

What you have will do nothing to really prevent any twisting.

[Paul Y]

Thanks for the advice Mike.

Yes, i am trying to reduce twist.

Please bear with me whilst I repeat back what you have written in my words to make sure I have got it.

And by words I mean a poor picture



So get that I will need to cross brace the forward red X going as far forward as I can.

Please ignore the white that is the original tape.

On the rearward section I have moved the shocks to outside the chassis and plane on having a rear mounted fuel tank at some point.

Therefore not sure if I can get a X brace back far enough to make a difference and still allow a tank to be fitted.

Would the second set of red not suffice?

Or is there another option that i am missing?

I am going to be raising the bed floor as a small c notch is going in so will have to put a crossmember in to support the mid section of floor, would it be more advantageous to use that as the anchor point for the bracing?

Again, keen to learn so advice gratefully accepted.

Thanks,

P.

[PGSigns]

The frame forms a box from the forward cross member to the rear one with the front and rear suspension twisting on each end. So the entire frame will twist. Any thing you do outside the box will not do much. The more you do to stiffen the middle where the loads have the most leverage will be the most effective. If you look at the Porter built stiffener and what No Limit is doing with there frames you can some ideas of what they are doing.
Jimmy

[vin63]

If you're looking to reduce torsional movement of the frame just being the cab, the only effective thing you can do is build a roll cage that includes the requisite down bars, main hoop, and forward bars that are welded to the frame - these bars provide strength and reinforcement in the vertical plane.

The factory box/ladder configured frame combined with the attached sheetmetal is actually very strong in the horizontal plane. You can add a large X structure (example below) between the frame rails from the rise of the front frame to a point behind the cab that will help, but, it will not be nearly as effective as a roll cage in weight and torsion resistance.

[Paul Y]

Gentlemen,

Thanks you for the input. I suppose I am just looking to see if there is any improvement that I can achieve for low to minimal cost using some box section and a welder.

Vin, Not building a race car - had my fill of caged cars on the street so, whilst it would be the ultimate in rigidity, not going to cage it.

Jimmy, looked at the Porterbuilt and no limits stuff and both are beyond my pocket and skill levels.

So, the question stands. If I was to use some box tubing what would be the best position to fix it in AND would I feel any benefit or am I wasting my time?

I read through the make it handle thread and there is reference to strengthening the frame within it but I cant visualise what that would look like.

So if anybody would like to create the dummies guide I would willing be the guinea pig and document it for the benefit of all.

P.

[vin63]

Originally Posted by Paul Y

So, the question stands. If I was to use some box tubing what would be the best position to fix it in AND would I feel any benefit or am I wasting my time?

Unless you create a large X structure in between the frame rails that extends from the front of the frame (about the mid mount of the motor) to behind the cab, just putting either diagonal gussets or X braces behind the cab will do very little except add weight and put unnecessary heat in the OE frame. Boxing the frame will provide a lot more rigidity and strength than adding frame gussets behind the cab.

You can purchase center frame X kits separately just like in the photo I posted above.

[Paul Y]

Thanks Vin!

P.