frame mounted hitch??...Toyota/Lexus??

[OrangeTexan]

Since my birthday is a week away... I am old too.



I love the academics of this discussion, as sort-of off-topic as it is. Must ... resist ...

Okay, I failed:

To a point, I agree with you, but trends on light duty and medium duty vehicle designs have headed in the fully-boxed frame direction, where one will need to temper to de-stress the steel after forming, and possibly again after welding. Given that the milder steels don't take well to repeated treatments (case in point, the early Tacomas, early Dodge Cummins Turbo frames) without being alloyed somewhat differently, one would surmise that Toyota would use a more modern steel than they used in the 90's unless they felt like doing what they did with the Tacomas for us.

And boxed designs are also much harder for frame people (see below) to get straight again compared to U frames.



Most certainly true, unless you have a body shop frame guy that isn't a total idiot. I got lucky - my maxima got clipped by someone doing 50, and it drives the same today as it did then. Of course, it's also worthless now.

Good discussion.

If you look around, you'll find that Toyota recommends repair shops to only cold work the frame on later models Tacomas/ 4Runners, etc. and they specifically site HSS. This means they are using older HSS technology in the frame. Also know that you cannot temper many of these new HSS without it losing its strength properties. Its all about the quench when it is cooled and what kind of grain structure is formed. The process that they are produced and formed with are very tight and deliberate to give the steel these properties. That is why they do not recommend hot straightening, or in the case of UHSS no repair at all.

Hopefully yall are not losing my point as it might seem we are going off tangent a bit. The point I am trying to make, Toyota is not using exotic HSS in the main frame assembly. It makes more sense to use something that is repairable through common body shop techniques like cold or hot straightening and sometimes rewelding.

The new exotic HSS and UHSS are left to body structure where the steel is thinner for weight savings. Even when the body structure is assembled with welds, they use robotic welding techniques that are very tightly controlled proprietary processes developed so they minimize the welding affects on the UHSS properties.

That being said, I would not expect the cross member to take these loads repeatably based on the assumption that it might be some exotic HSS.


Hopefully we are not too far off topic...

 

[Antman]

Good discussion.

If you look around, you'll find that Toyota recommends repair shops to only cold work the frame on later models Tacomas/ 4Runners, etc. and they specifically site HSS. This means they are using older HSS technology in the frame. Also know that you cannot temper many of these new HSS without it losing its strength properties. Its all about the quench when it is cooled and what kind of grain structure is formed. The process that they are produced and formed with are very tight and deliberate to give the steel these properties. That is why they do not recommend hot straightening, or in the case of UHSS no repair at all.

Hopefully yall are not losing my point as it might seem we are going off tangent a bit. The point I am trying to make, Toyota is not using exotic HSS in the main frame assembly. It makes more sense to use something that is repairable through common body shop techniques like cold or hot straightening and sometimes rewelding.

The new exotic HSS and UHSS are left to body structure where the steel is thinner for weight savings. Even when the body structure is assembled with welds, they use robotic welding techniques that are very tightly controlled proprietary processes developed so they minimize the welding affects on the UHSS properties.

That being said, I would not expect the cross member to take these loads repeatably based on the assumption that it might be some exotic HSS.


Hopefully we are not too far off topic...

Damn!

Whenever I read one of these posts I get this image in my head of myself and an Engineer stranded on an island in the middle of nowhere, trying to get home.

I would hack my boat out of an old tree with a rock and some seashells and hit the ocean. Bye!

Mr Engineer would analyze the wood grain, age of the tree, and condition of the wood based on age, atmospheric conditions over the last 50 years, and insect damage. Then he would spend weeks figuring out which rock would yield the most work/effort . I don't even know what he would do with the seashells, but he could tell me about it his plans when I sent someone back to rescue him...

 

[1engineer]

Good discussion.

If you look around, you'll find that Toyota recommends repair shops to only cold work the frame on later models Tacomas/ 4Runners, etc. and they specifically site HSS. This means they are using older HSS technology in the frame. Also know that you cannot temper many of these new HSS without it losing its strength properties. Its all about the quench when it is cooled and what kind of grain structure is formed. The process that they are produced and formed with are very tight and deliberate to give the steel these properties. That is why they do not recommend hot straightening, or in the case of UHSS no repair at all.

Hopefully yall are not losing my point as it might seem we are going off tangent a bit. The point I am trying to make, Toyota is not using exotic HSS in the main frame assembly. It makes more sense to use something that is repairable through common body shop techniques like cold or hot straightening and sometimes rewelding.

The new exotic HSS and UHSS are left to body structure where the steel is thinner for weight savings. Even when the body structure is assembled with welds, they use robotic welding techniques that are very tightly controlled proprietary processes developed so they minimize the welding affects on the UHSS properties.

That being said, I would not expect the cross member to take these loads repeatably based on the assumption that it might be some exotic HSS.


Hopefully we are not too far off topic...

Let me see if I can bring this discussion back on topic with a few thoughts and musings:

First and foremost - why would anyone in their right mind want to add weight and complexity to something that is perfectly good at what it is designed to do unless they want to have it do something MORE?

The current design of the 4Runner hitch is just fine for 500 lb tongue weight and 5K trailer weight. Remember that the people who designed this had a few more tools at their disposal than pictures of a different design on an internet forum. I feel quite comfortable that this design is nominal while still within Toyota's safety factor. Everyone can discuss all they want about metallurgy and fastener location and weld strength but until one of you shows me a calculation or two I call BS on this entire thread.

The truth is increasing load carrying ability involves much more than adding a different hitch - IF you want to maintain some level of SF. As far as using a WDH: I really like all the broscience discussed here but as I said before, unless you show me some calculations and/or instrumented tests of torsion forces on the frame in all conditions of crossmember loading AND shear calculations of threaded fasteners ALONG WITH deflection calculations of the actual hitch then, quite simply, none of this means absolutely anything.

So to the OP: For whatever reason put a different hitch on - by all means. If you think that it will be stronger because it is attached differently that's great. I will say though that your reasoning and logic is flawed and while it might be OK, it also might not. Good luck.

 

[1engineer]

Damn!

Whenever I read one of these posts I get this image in my head of myself and an Engineer stranded on an island in the middle of nowhere, trying to get home.

I would hack my boat out of an old tree with a rock and some seashells and hit the ocean. Bye!

Mr Engineer would analyze the wood grain, age of the tree, and condition of the wood based on age, atmospheric conditions over the last 50 years, and insect damage. Then he would spend weeks figuring out which rock would yield the most work/effort . I don't even know what he would do with the seashells, but he could tell me about it his plans when I sent someone back to rescue him...

I like that analogy but there is more to the story: While you hack your boat out of an old tree and HOPE you get home, I will take a little extra time figuring things out and KNOW I will get home. :

The most important part of designing anything is first and foremost to put safety above everything so nobody gets hurt or killed, and to do so with the best of your ability. It's all fun and games until someone gets hurt.

 

[OrangeTexan]

Let me see if I can bring this discussion back on topic with a few thoughts and musings:

First and foremost - why would anyone in their right mind want to add weight and complexity to something that is perfectly good at what it is designed to do unless they want to have it do something MORE?

The current design of the 4Runner hitch is just fine for 500 lb tongue weight and 5K trailer weight. Remember that the people who designed this had a few more tools at their disposal than pictures of a different design on an internet forum. I feel quite comfortable that this design is nominal while still within Toyota's safety factor. Everyone can discuss all they want about metallurgy and fastener location and weld strength but until one of you shows me a calculation or two I call BS on this entire thread.

The truth is increasing load carrying ability involves much more than adding a different hitch - IF you want to maintain some level of SF. As far as using a WDH: I really like all the broscience discussed here but as I said before, unless you show me some calculations and/or instrumented tests of torsion forces on the frame in all conditions of crossmember loading AND shear calculations of threaded fasteners ALONG WITH deflection calculations of the actual hitch then, quite simply, none of this means absolutely anything.

So to the OP: For whatever reason put a different hitch on - by all means. If you think that it will be stronger because it is attached differently that's great. I will say though that your reasoning and logic is flawed and while it might be OK, it also might not. Good luck.

Well, I agree we could all sit here and over-analyze this subject to death, but really in the end its all what you are personally comfortable with. Although the analysis you outlined would be fun, its something I'm not that motivated to do, especially since it would only be for my and maybe your benefit (plus it would cost me more to do it than buying a F-250).

Everyone else is just gonna do what they feel is OK with this hitch. My personal feeling is to err on the cautious side. To each his own.

 

[homeyclaus]

Good discussion.

If you look around, you'll find that Toyota recommends repair shops to only cold work the frame on later models Tacomas/ 4Runners, etc. and they specifically site HSS. This means they are using older HSS technology in the frame. Also know that you cannot temper many of these new HSS without it losing its strength properties.

[snip!]

The point I am trying to make, Toyota is not using exotic HSS in the main frame assembly. It makes more sense to use something that is repairable through common body shop techniques like cold or hot straightening and sometimes rewelding.

[snip]

That being said, I would not expect the cross member to take these loads repeatably based on the assumption that it might be some exotic HSS.

Hopefully we are not too far off topic...

I don't think anyone is saying that they expect the frame steel to be exotic, but I certainly don't expect the steel to be the same steel they used in the 80's or 90's. And I do expect that they have applied our improved understanding of metallurgy and heat treatment to the frame steel.

 

[Titanpat57]

I like that analogy but there is more to the story: While you hack your boat out of an old tree and HOPE you get home, I will take a little extra time figuring things out and KNOW I will get home. :

The most important part of designing anything is first and foremost to put safety above everything so nobody gets hurt or killed, and to do so with the best of your ability. It's all fun and games until someone gets hurt.

or loses an eye....

 

[homeyclaus]

I like that analogy but there is more to the story: While you hack your boat out of an old tree and HOPE you get home, I will take a little extra time figuring things out and KNOW I will get home. :

The most important part of designing anything is first and foremost to put safety above everything so nobody gets hurt or killed, and to do so with the best of your ability. It's all fun and games until someone gets hurt.

And I find the idea of being on a desert island very appealing, as long as both of you only come by to visit once in a while. Fewer people than northern Alberta, better weather, fish to eat? I am in.

And yea, it's all fun and stuff until people get hurt.

 

[drnick]

good grief!!

I originally posted this to ascertain if you can install a frame mounted hitch on a gen 5 4runner,now I see that you can install a lexus frame mounted hitch
THANK YOU Alamorunner...although the center part of the mounting might need a little more"Fitting"...but my original intent to install a frame mounted hitch was because ya can't put 500lbs of tongue wght on the OEM crossmember hitch,because the axle will sit on the bumpstops!...and on a 2wd
ya can't get airbags( I asked,they have no listings for 5gen 2wd) and there
are no listings for any type of "Monroe Load Levelers" either...other then the Timbrens,which I installed,the frame mounted hitch was my only other option
that might have lessened the sag.THX for all the Info though,it was very informative...although it did go off course a bit:hatsoff:

 

[Jtraskell]

drnick, try this. Instead of asking the dealer or manufacturer of the airbags about a fit for a vehicle which is rare by most account's, (and really, who knows if who you talked too has any idea....), contact a local dealer and ask for the rear spring part number for both the 2wd and the 4wd. If the same....then the airbag will fit. If different, ask how? You might be pleasantly surprised. Be safe.

 

[Ivy Mike]

engineer and orangeTX, would you be comfortable hanging a motorcycle hitch hauler with a 250# dirtbike on the factory hitch?

 

[drnick]

drnick, try this. Instead of asking the dealer or manufacturer of the airbags about a fit for a vehicle which is rare by most account's, (and really, who knows if who you talked too has any idea....), contact a local dealer and ask for the rear spring part number for both the 2wd and the 4wd. If the same....then the airbag will fit. If different, ask how? You might be pleasantly surprised. Be safe.

Jtraskell,did that,parts man was cluless/useless,it seems that Toyota(in there
parts computer)doesn't list parts the way GM/Ford/Dodge,and they couldn't
seperate 4wd/2wd springs unless I get vin# from a 4wd,and compare that with 2wd???so they say???...and there are listings for airbags in different sizes(4"x8",4"x9",4.75"x8",and a couple of others)I would have to measure
an unladen spring to find out.

 

[Jtraskell]

Yea, I ran into the same thing for other reasons, the vin # issue. I was at the dealership when they hit me with that, so I went out to the lot, wrote down an "applicable" vin, then the part's guy was able to help me. Go to a dealer and find a comparable 4wd and use that vin.....you should then get a good answer. I cannot imagine why there would be any difference between the rear suspension parts of a 4wd vs 2 wd 4runner. Maybe the front suspension, but the rear should be the same. Here is another choice. Order the Air Bags for the 4wd 4runner, if by chance it does not fit, return it. Most credible retail outlets will refund your money if there is a problem. The most you will be out is the shipping costs...... Be safe.

 

[lezavw90]

To bring back a year old thread. So this past Easter weekend had some free time while the kids were hunting for eggs at the in laws. We got the 4runner up on the hoist. Took the oem hitch off the truck to find that it is not the crossmember that "bent" (which is what the dealer told me) it was the hitch itself. It was bent quite bad(sorry no pics yet). Which is a bunch of doody as i barely had any spring tension on it, and from looking at some of your pics you guys load those bars quite a bit.
Out of curiosity I had purchased the Lexus hitch setup last August which has been sitting at my father in laws shop.
We installed the hitch. The frame mount hitch bolts directly using factory holes, as well as the crossmember adapter uses factory holes as well. The problem we ran into is that the 4runner crossmember sits 1in farther away from the rear axle than the Lexus' .What we did to solve this was throw the spacer plates in as per the manual but instead we just welded the whole thing together(Father in law has a wonderful shop full of welders, plasma cutters, and other fun toys). The only other issue we ran into was the relocation of the trailer plug wiring. On the Canadian Limited the bumper skirts are lower than the sr5 and te so we had to drill one hole to drop the receptacle down 1in.

The entire assembly sits 1in lower than the factory hitch, with another couple hours you could cut and weld some more and make it the same, but I'm not concerned with clearance.

The whole install took about an hour.


Now that I have a super beefy hitch I think I'm going to go spend the weekend looking for a new 30ft travel trailer.

The above sentence is a joke. To people reading this thread you still have to follow the vehicles weight ratings not the hitches rating.

 

[eddiebx]

To bring back a year old thread. So this past Easter weekend had some free time while the kids were hunting for eggs at the in laws. We got the 4runner up on the hoist. Took the oem hitch off the truck to find that it is not the crossmember that "bent" (which is what the dealer told me) it was the hitch itself. It was bent quite bad(sorry no pics yet). Which is a bunch of doody as i barely had any spring tension on it, and from looking at some of your pics you guys load those bars quite a bit.
Out of curiosity I had purchased the Lexus hitch setup last August which has been sitting at my father in laws shop.
We installed the hitch. The frame mount hitch bolts directly using factory holes, as well as the crossmember adapter uses factory holes as well. The problem we ran into is that the 4runner crossmember sits 1in farther away from the rear axle than the Lexus' .What we did to solve this was throw the spacer plates in as per the manual but instead we just welded the whole thing together(Father in law has a wonderful shop full of welders, plasma cutters, and other fun toys). The only other issue we ran into was the relocation of the trailer plug wiring. On the Canadian Limited the bumper skirts are lower than the sr5 and te so we had to drill one hole to drop the receptacle down 1in.

The entire assembly sits 1in lower than the factory hitch, with another couple hours you could cut and weld some more and make it the same, but I'm not concerned with clearance.

The whole install took about an hour.


Now that I have a super beefy hitch I think I'm going to go spend the weekend looking for a new 30ft travel trailer.

The above sentence is a joke. To people reading this thread you still have to follow the vehicles weight ratings not the hitches rating.

:worthless

But really though, I am very interested in seeing pictures!

 

[lezavw90]

Look on page 4 post 54. It looks exactly like that except in the gap that the pictures show, we put the factory supplied spacers and welded the whole thing in place. If the crossmember lined up correctly there would be 4 bolts that go up through the hitch into the hitch adapter.

 

[AlexJet]

Look on page 4 post 54. It looks exactly like that except in the gap that the pictures show, we put the factory supplied spacers and welded the whole thing in place. If the crossmember lined up correctly there would be 4 bolts that go up through the hitch into the hitch adapter.

It's an old thread, but have you did your welded plate?

Looking at the pictures, I was wondering if you could of cut off the welded nuts from the cross-member plate, open up/elongate the holes or drilled a new ones (depending on where it sits as it's not visually clear from the images), and reeled the nuts in a new position...??? This should of be workable, especially if you have welding equipment.

 

[AlexJet]

Did anyone tried to install '04-'09 Lexus GX470 frame mounted Hitch (p/n: PT228-60540) on the 5th Gen.?
Based on the discussion, we know that '10-'17 Lexus GX460 frame hitch (p/n: PT228-60100) would fit the Frame rails, but what about the previous generation GX470 one?
I believe visual difference between those two are that GX470 hitch has round tube and GX460 hitch use square tube.

 

[e60ral]

Toyota has engineers, FEA, standards based testing, empirical testing, etc...

 

[AlexJet]

I passed by Lexus dealer last night. They have a different part number for GX460, it's PT228-60140.
Does anyone knows what the difference between PT228-60100 and PT228-60140? Lexus parts guy didn't know...

BTW, I was quoted $640 for the hitch and $420 for the cross-member support bracket which I believe also needed to install it.