Toyota Tailgate Facts

[SuperHatch]

Originally Posted by jkd

Oh yea? Let me get my ATV on my ramps and then have you try to lift the rear of the ramps off the ground. You might want to rethink that one, driving up the ramps even with the front ATV axle on the tailgate, Mother Earth is still supporting a good part of the load.

I misused the word "All", but there is still a great deal of load on the tailgate that would otherwise not be there.



You have the force of the weight of the ATV. For arguments sake, we'll say the ATV weighs 800lbs with you on it (600lb ATV, 200lb rider) and the CG is such that the weight is evenly split on the F/R axles (400lb each). The force B is 400lb, loaded approximately 2/3 the way up the ramp. We can also assume the ramp angle C is 30 degrees. The rear axle load B then is distributed between the resultant force D ("mother earth") and force E (the tailgate or that product). We can break force B into it's components, and when doing so we find out that the force perpendicular to the ramp is ~350lb. [ 400*cos(30) ]. Since that force is 2/3 the way up the ramp, we need to force balance the loaded member. There is a component of force D and E supporting this weight. According to Newton, the sum of the moments on any loaded member equals zero around any given point. If we analyze the moments around the point where the ramp touches the ground we have a moment of 400lb x 2L/3 and another equal and opposite moment of xlb x 3L/3. 267L = xL, the L's cancel, and we have a force of 267lb on the gate perpendicular to the ramp. The component of this force acting downwards is 308lb ( 267/cos(30) ).

Considering the rear axle load assumption of 400lb on the ATV, I would say that 308lb on the gate is a very good deal of additional stress that could cause cracking.

I made a lot of assumtions in this calculation, but the gist is there...

[AlaskaCub]

Originally Posted by SuperHatch

Considering the rear axle load assumption of 400lb on the ATV, I would say that 308lb on the gate is a very good deal of additional stress that could cause cracking.

I made a lot of assumtions in this calculation, but the gist is there...

I knew that there had to be a smart guy in the bunch but your formula basically says that 2 men cant sit on the tailgate of a Tundra (2 men 200lbs each which is conservative = 400 lbs give or take). That explains why them salesman at the dealerships are cracking tailgates from sitting on them. <grin>

Pretty sure you can walk into any truck dealership in America and 2-3 men sitting on the tailgate arent gonna crack it, with the exception of the 2007 Tundra.

Theres definately something wrong, and your formula helps the argument for all of us.

[SuperHatch]

I'm not arguing that there's something wrong, I was just arguing that the product mentioned earlier in this thread would actually help.

[NOVA Tundra Owner]

My Owner's Manual says not to exceed 100 pounds on the tailgate when using the bed extender. My 2001 F150 says the same thing.

[daless2]

Originally Posted by SuperHatch

I misused the word "All", but there is still a great deal of load on the tailgate that would otherwise not be there.



You have the force of the weight of the ATV. For arguments sake, we'll say the ATV weighs 800lbs with you on it (600lb ATV, 200lb rider) and the CG is such that the weight is evenly split on the F/R axles (400lb each). The force B is 400lb, loaded approximately 2/3 the way up the ramp. We can also assume the ramp angle C is 30 degrees. The rear axle load B then is distributed between the resultant force D ("mother earth") and force E (the tailgate or that product). We can break force B into it's components, and when doing so we find out that the force perpendicular to the ramp is ~350lb. [ 400*cos(30) ]. Since that force is 2/3 the way up the ramp, we need to force balance the loaded member. There is a component of force D and E supporting this weight. According to Newton, the sum of the moments on any loaded member equals zero around any given point. If we analyze the moments around the point where the ramp touches the ground we have a moment of 400lb x 2L/3 and another equal and opposite moment of xlb x 3L/3. 267L = xL, the L's cancel, and we have a force of 267lb on the gate perpendicular to the ramp. The component of this force acting downwards is 308lb ( 267/cos(30) ).

Considering the rear axle load assumption of 400lb on the ATV, I would say that 308lb on the gate is a very good deal of additional stress that could cause cracking.

I made a lot of assumtions in this calculation, but the gist is there...

Hi SuperHatch,

Thanks for your post. I can get into this stuff!!!!

You’re right, the jest of it is there in your explanation, yet the weight sitting on the edge of the tailgate will change, as the ATV is rolled up the ramp because the angle, relative to the wheelbase will vary logarithmically with distance of the ATV into the bed.

One might also want to be concerned with the length of the wheelbase of the ATV and the length of the ramps as well. As both are major factors in these calculations.

A few years back I wrote an article to help folks understand the physics of this.

The effort was to help folks determine exactly where the Center of Gravity and Roll Over Angles for their Off Road Vehicles is located.

If you have an interest in reading it here’s the link.

http://www.jeepaholics.com/tech/cog/

There is a downloadable spreadsheet to go with the article. Don’t miss it if you want to do this.

If anyone cares to determine the Center of Gravity, and what the Roll Over Angles would be for your Tundra, you can use this write-up, take a few measurements and plug them into the spreadsheet. All the math is automagically done for you.

It also may help you understand the loads put on your tailgates using ramps, and why one ATV of a given weight might cause a problem (The shorter the wheelbase, the higher the percentage of weight on the tailgate), and another ATV of the same weight does not cause a tailgate issue (Longer wheelbase puts less weight, on the tailgate edge at any moment in time.)


Maybe someone will find it helpful.

Frank

[daless2]

Originally Posted by Keywasted

Frank,
It is a shame that your excellent thread has been hijacked and some are trying to turn it into a pissing contest! Though some of the comments are laughable; metrictundras " common cents" had me rolling, the issue and intent of your thread has great value to those with the tailgate failures.

I disagree completely with the "let's wait and see what Toyota does" attitude of some of the riders. LOL. I guarantee you that if I had a tailgate problem I would want it fixed RIGHT NOW!

So please keep your thread going and writers, please stay on topic. We might need this one day!

BTW metric, unfortunately, many people most certainly do judge your intelligence and education by the words you use, both written and spoken. Just my 2 sense.LOL

KeyWasted

Thanks for your support in seeing the potential value of a thread like this, but hey what you going to do.

People are fine, so long as we don’t get into the name-calling and insults. I learned long ago not everyone will agree with me, or my approach to things, and that’s fine too.

That said I feel certain there are other FACTS out there that we can be capturing and recording in this thread dealing with the Tundra Tailgate Failures.

If you are having a tailgate problem, and you have some written correspondence with Toyota that is related to this topic, please post it here.

What Toyota says, may not be true, but it is a FACT that Toyota has said it.

Please document it here.

Toyota knows this too. That is why you don’t see a lot of written commitments on this topic from Toyota.

In truth, Toyota could manage this problem a lot better with a Simple Press Release. Something along the lines of:

"We recognize there have been failures with some Toyota Tundra Tailgates. Toyota commits to identifying the root cause of these design failures and fixing every Tundra Tailgate”

I would then shut up and give them the time to redesign the tailgate so that it doesn’t break or fall off. Until then I am not going anywhere.

But that’s just me.

Until I hear something “Official” from Toyota in that regard, I am busy collecting “FACTS”, hopefully directly from Toyota.

Frank

[Sanosuke]

Originally Posted by SuperHatch

I misused the word "All", but there is still a great deal of load on the tailgate that would otherwise not be there.



You have the force of the weight of the ATV. For arguments sake, we'll say the ATV weighs 800lbs with you on it (600lb ATV, 200lb rider) and the CG is such that the weight is evenly split on the F/R axles (400lb each). The force B is 400lb, loaded approximately 2/3 the way up the ramp. We can also assume the ramp angle C is 30 degrees. The rear axle load B then is distributed between the resultant force D ("mother earth") and force E (the tailgate or that product). We can break force B into it's components, and when doing so we find out that the force perpendicular to the ramp is ~350lb. [ 400*cos(30) ]. Since that force is 2/3 the way up the ramp, we need to force balance the loaded member. There is a component of force D and E supporting this weight. According to Newton, the sum of the moments on any loaded member equals zero around any given point. If we analyze the moments around the point where the ramp touches the ground we have a moment of 400lb x 2L/3 and another equal and opposite moment of xlb x 3L/3. 267L = xL, the L's cancel, and we have a force of 267lb on the gate perpendicular to the ramp. The component of this force acting downwards is 308lb ( 267/cos(30) ).

Considering the rear axle load assumption of 400lb on the ATV, I would say that 308lb on the gate is a very good deal of additional stress that could cause cracking.

I made a lot of assumtions in this calculation, but the gist is there...

One minor thing you missed -- the weight of the ramp itself, otherwise a good explanation. How about force per sq inch exerted on the tailgate at the lips at the top of the ramp? This is the primary concerning force for causing the tailgate to display stress fractures.

I'll be posting actual figures when I do some measurements in the real world using *one* ramp as one-half of the representative weight. I have a Polaris sportman 400 quad and a heavy steel ramp for it so I'll go ahead and measure the height of the top lip of tailgate to ground and then measure the angles out for you. This would only be representative of the actual ramp I use to load my dirtbike (A '04 Honda XR250R at about 250 pounds w/full tank) however.

Update:
7' ramp extended towards a 33.55" height, gives me a 23.54 degree angle. With a 250 pound dirtbike w/front tire on tailgate and rear tire off, the force exerted downwards, at the top of the tailgate this would be 270 pounds, with two ramps this would be a whooping 540 pounds if loading two bikes simulateously. IF loading my polaris quad which weighs in around 500 pounds, this would be 545 pounds distributed across two ramps exerting onto the tailgate or 272.50 pounds on either ramp pushing on the tailgate. The pressure applied on the tailgate is even more significant given the little surface area of the bolt that presses down on the tailgate (think of it as a finger pressing down on a ledge and you have the lip design of my loading ramp). These figures would be compounded with the extra weight of the ramp resting on the tailgate's lip. You get the good idea of the pressures involved in causing our tailgates to crack at the seams.

Sanosuke!

[semcoll]

I'm still trying to find ways to help you guys - How about some rigid extensions at the top of the ramp where it overlaps the tailgate. This would distribute the weight away from the weak tailgate lip further towards the front of the truck or closer to the pivot axis of the tailgate?

Cub - I think 2 grown men can sit on the tailgate just fine, since their weight is on their a$$cheeks towards the middle of the gate as opposed to the edge. I think the only problem would be - why would they want to ?

[gobblerman]

My Owner's Manual says not to exceed 100 pounds on the tailgate when using the bed extender. My 2001 F150 says the same thing.

I believe what it says is that the bed extender may be used to secure loads up to 100 pounds with the tailgate down. This does not imply that the tailgate is rated for 100 pounds but that the extender is. Now the extender weight plus 100 lbs may be the limit on the tailgate when driving due to jarring which would increase the forces on the tailgate but this is different than the more static forces of loading onto a tailgate.

[mslc10]

Originally Posted by guntech

I really don't think that Toyota would purposly try to hold back that info so that they are not badmouthed. I think it was something that they just didn't put enough engineering thought into. Sure, it sucks, but they will make it right - I'm sure.

I don't understand what makes you think they will make this right??? when has any mfgr done something to make it right? have you heard ford recall all the 2004 f150s that will have broken sparkplugs? NO thats why a fords resale value is in the crapper. I'm not holding my breath for toyota to call me up and say" we need to replace your tailgate because we made it cheaply to save a buck".

[jkd]

The shorter the wheelbase, the higher the percentage of weight on the tailgate

That theory doesn't hold water because of the fact that the long wheelbase ATV total weight is about twice the weight of the smaller short WB models. My Polaris 500 is a 715 lb. pig and a short WB Susuki is 400 or less. It's not ramp weight alone causing the problem. Like I posted, I have an aluminum sheet installed on my gate and the other day I bounced my 175 lb. bod up and down as I sat on the middle of the sheet while looking at the metal separation area as best I could. I could see white primer appear off and on as I bounced showing the inner and outer skin working against each other. I'm not saying the top edge can't be bent, but if you pull the black trim off like I did the other day you'll see the outer skin wraps over and is spot welded (not crimped) to the inner in 15 spots along the top edge. Also if you take time to remove the access panel and see how and where the gussets are I think you'll end up with a more well informed idea of just where the problem lies.

One minor thing you missed -- the weight of the ramp itself,

My aluminum ramps are 40ft from the back door so I just went out and with one end on the ground and with the other end tailgate height I held the tailgate end up with just my forefinger so that doesn't enter in to the problem to a great extent.
Rather than trying to impress anyone with a theory of angles, weights during loading, and on and on, personally I'll just agree with the service manager I talked to this morning, the tailgate should handle an ATV just like the other brands.

[mslc10]

there used to be a tailgate protector...here it is...Tail Gate Protectors by Dee Zee Tailgate Protection TailGate Caps Full Tailgate Protectors would that help???

[Sanosuke]

Originally Posted by jkd

That theory doesn't hold water because of the fact that the long wheelbase ATV total weight is about twice the weight of the smaller short WB models. My Polaris 500 is a 715 lb. pig and a short WB Susuki is 400 or less. It's not ramp weight alone causing the problem. Like I posted, I have an aluminum sheet installed on my gate and the other day I bounced my 175 lb. bod up and down as I sat on the middle of the sheet while looking at the metal separation area as best I could. I could see white primer appear off and on as I bounced showing the inner and outer skin working against each other. I'm not saying the top edge can't be bent, but if you pull the black trim off like I did the other day you'll see the outer skin wraps over and is spot welded to the inner in 15 spots along the top edge.

Go ahead, measure both quads in the length and then try lifting each one up by the front. The engine is closer to the front in both quads so there is _MORE_ weight put down at the front than there is at the back.

My aluminum ramps are 40ft from the back door so I just went out and with one end on the ground and with the other end tailgate height I just held the tailgate end up with just my forefinger so that doesn't enter in to the problem to a great extent.
Rather than trying to impress anyone with a theory of angles, weights during loading, and on and on, personally I'll just agree with the service manager I talked to this morning, the tailgate should handle an ATV just like the other brands.

Those aluminum ramps don't weight very much but they STILL weigh something!!!!! I have _STEEL_ ramps which hold up much better than those aluminum ramps you have.

Sanosuke!

[jkd]

I have _STEEL_ ramps which hold up much better than those aluminum ramps you have.

It is a shame that your excellent thread has been hijacked and some are trying to turn it into a pissing contest! Though some of the comments are laughable

As this poster already said, how about keeping it on topic?

[tc1001]

It would be good to have a picket line/protest outside of Toyota and get some CNN type coverage. Toyota would love their "known" tundragate issue to get some real nation wide coverage.