5th Wheel Hitch Installed

And keep in mind this bracketry is being retrofitted to a truck it was not intended to be installed on... The more safety factors you can build in, the better.

 

100% ^^^

i'd wager the frame is actually the weakest link at this point.

 

If i can find them I'll probably go with grade 8 carriage bolts for the top, and might as well replace the side brace bolts as well.

As far as making the frame more beefier, I added 1/4" Steel plate on the other side of those bolts. (Don't let me forget pics). The only other way I can think of making the frame stronger would be to box it in? Any other suggestions?

 

Yeah, I think I'd want that thing fully boxed from the back of the cab back. That 5th wheel looks like it'd put a large force down on the frame and about 6" forward or backward, the leaf spring mounts put a large force upward. I don't know how strong the frames really are in the Tacoma but I know they weren't created with a 5th wheel in mind.

 

the plate on the other side will stiffen it a little in the sense that that portion will not bend as easily, but what i'd be worried about is the bolts stretching those holes in the frame or potentially cracking it. with the way you have it set up, the weight is being carried by the bolts and the holes in the frame.

stress (pressure) is equal to the force applied over the area to which it's being applied. the area in your case is the bolt diamiter times the thickness of the frame. this means that you have a high stress concentration at each bolt hole. now if you were to put a block of some sort between the frame and underside of each bracket to support the virticle load, that area of the frame (which is much larget than the crossectional area at the bolt holes) would then be supporting the downward force. that takes the virticle shear component off or the bolts and holes in the frame. then they only have to handle the longitudonal shear and lateral (tensile) forces.

or, if you were to weld that plate you have on the back of the frame, that would increase the effective area of the bolt hole that is supporting the weight, in turn, lowering the stress.

edit: what diamiter hardware are you using by the way?

 

this

 

I'll probably add a support under all the angle brackets there. I've looked at other installs for these rails and they're similar but the frames were just a little bit more thicker, so that's why I added the extra plate.

I'm using 1/2" Bolts, Grade 8 Now

 

This statement worries me...why would you buy the camped "hoping" that you can make your current truck tow it? I am all for ingenuity and like the fact that you are doing custom work, but I think you should stop right now and go buy the correct truck. You are pushing way to many unkowns to their limits and no matter how many safety factors you build in there is always a weakest link that will pay the price (and hopefully not cause an accident in the process). Did you ever sit down and wonder why nobody offers a gooseneck hitch in this class of trucks?

Think hard, good luck and be safe.

 

A stock vehicle has its limits. If everyone abides by that and says well it is what it is, it can't do anything else, this forum wouldn't even be here.


Modifications that people do include a vast number of things. From Lifts, to Tires, Spacers, to extra oil/AT transmission coolers for more towing, Receiver Hitches (wonder who first came up with those) More Horsepower, More carrying capacity, Different Gears, Locking Front/Rear Diffs, Sliders etc..

It all had to start somewhere. I'm sure the first guy who made a "lift kit" didn't have to many fans as well. Lifting a truck up? Man that's insane, it'll just tip over when you turn, you're crazy! But they figured it out. Or how about adding more horsepower, the transmission can't handle that power, it'll blow the valve covers off, or maybe break the axles!

I'm not saying this is the best idea. But I am taking many, many precautions. Before it goes out on ANY public road, it'll be tested. If it works, wonderful. If things go wrong, and it doesn't, then we'll go from there.

I appreciate all the concern, for my safety and for the safety of others.

Thanks,

 

But there's a reason why Toyota (the manufacturer of this vehicle, in case you didn't know) states right in every single owner's manual that this truck is not designed to tow 5th wheel. And there's a reason why Toyota does not warranty modifications.

Regarding lifts, etc. The companies that make those mods warranty their own part. You are designing this thing yourself. Are you going to apply for a warranty for it? What about insurance if anything goes wrong?

 

After looking at the way you mounted the rails, I don't think it will work well. The rails need to be bolted directly to the frame, not on angle brackets. What you will find is that from braking and forward movement over time it will waller out those brackets and cause failure. I pull many trailers and have installed many hitches (5ers) and can tell you from experience you'll going to have trouble with the hitch. I pull a 16k Cardinal 5th wheel camper with a Dodge Diesel. I have been camping with 5ers for many years and a member of woodalls. I have seen this type of install fail dozens of times. Your best bet is to weld those brackets solid. JMHO

 

off topic but I had no idea the composite bed was so thick...

 

After working at a camper dealership I haven't seen many half ton trucks with a fifth wheel or goose neck in them! There are a ton of factors with doing this...Fifth wheels set up higher so there is allot more drag going down the road and then the weight distribution is not the same as a travel trailer there is more weight on the hitch!

Every vehicle has a purpose, I love my tacoma but there is no way I would every even think about pulling a fifth wheel with it after pulling tons of them with all kinds of other trucks. I am all about being adventurous but this just seems pretty dangerous.

 

I have installed several hitches on Chevy's, Dodges, and Ford's and I have never seen one bolted to the frame...I am not sure how you would do that since you have a ridged truck bed in between the rails and the frame. We had a guy with a F350 get his trailer stuck 16k fifth wheel and a wrecker came out to pull the truck and trailer out from the ditch he was in and it bent the frame on the f350 before the brackets bent...but being that I am assuming the ones on this tacoma is home made I wouldn't trust them....we always bolted them on...if done right they won't move. But I would guess the frame on the tacoma will have issues....

 

That method of mounting to the frame is HORRIBLE! If you're determined to run that hitch, you need to have a more solid way of mountiing. Those raised brackets with extra empty holes and side mounted bolts is all bad. that might fly with a small trailer around 2kLbs, but not a 6KLb camper.

 

That's how just about every fifth wheel is mounted onto a truck! But like I have said all along I don't believe a tacoma frame is strong enough to handle the weight.

http://www.campingworld.com/shopping/item/base-rails-and-install-kit/12689

 

This idea is great for moving any 5th wheel or gooseneck around where a large 3/4 or 1ton truck mite be to big and cant turn sharp enough.

 

ok first thing a grade five bolt will stretch before it will shear, they are much better for vehicular applications where there is lots of jolting and vibrations, because a grade eight, which yes will hold more weight in shear but its so hard that it is brittle and for 6k pounds a grade 5 is plenty sufficient. the other thing i have to say is that the way you have your brackets mounted to the frame is horrible, you need to have a block in between your frame and the hitch and weld up those holes because that is also another weak point. But i do like your ingenuity i once fabbed up mounts for my old taco and i had tow bags they worked awesome. Not trying to troll just speaking from everything i have been taught in the last 7 years in fabrication, welding and machine shop classes

 

It looks like it will just tear through the frame being mounted raised like that. Oh well, good luck with it OP.