5th gen Body Mount Chop

[JSparky]

The need to trim the frame body-mounts/outriggers when fitting larger tires is pretty well documented here but there doesn't seem to be a whole lot of pictures. For those interested, I thought I'd throw up some pics from my experience doing this today. I met up with T4R member the_josh for this one. I'm really happy with his work and how it turned out. Functionally the whole outrigger has been shortened and capped with a curved-to-fit metal plate. Aesthetically it looks factory. It's not too difficult, just requires the right tools and the skills to use them. My tires used to rub when turned during up-travel, this opens up a lot more room to breath now!

 

[Seattle206]

Good work and thanks for the visuals. Definitely a must do for tires larger than 33s. I will consider this diy if I happen to get excess rubbing from larger tires.

 

[RaginTxn84]

great pics! nice to see it clear and up close.

just put on 285/70-17 KM2s on my runner - rubs the mount when at full lock - I unfortunately do not have the tools for this, so I will be soliciting a local shop for this - hopefully it turns out as well ray2:

 

[JSparky]

great pics! nice to see it clear and up close.

just put on 285/70-17 KM2s on my runner - rubs the mount when at full lock - I unfortunately do not have the tools for this, so I will be soliciting a local shop for this - hopefully it turns out as well ray2:

Yea I know how that goes, I was in the same boat. Luckily the_josh is local to me so I was able to employ him to do the work. Maybe another member near you can help out? I've seen a lot of gnarly looking body mount chops so I was psyched to find someone who's work is so clean.

 

[Randyman...]

...Aesthetically it looks factory...

That's purdy! A work of functional art IMNSHO.

While the stock mounts work fine with the factory tires, I never understood Toyota's rationale for the odd body mount perches and resultant interference issues with larger tires. I can observe no appreciable structural advantages to the stock config to your modified setup. Maybe one of the many engineers around here can chime in with a rational explanation for the factory perches?

 

[Jeremy556]

That's purdy! A work of functional art IMNSHO.

While the stock mounts work fine with the factory tires, I never understood Toyota's rationale for the odd body mount perches and resultant interference issues with larger tires. I can observe no appreciable structural advantages to the stock config to your modified setup. Maybe one of the many engineers around here can chime in with a rational explanation for the factory perches?

It's to prevent/reduce the front wheels intruding on the cab in an offset front end collision. The lower part of the mount is made of 780MPa ultra high strength steel (highest strength steel used in the frame).

 

[Randyman...]

It's to prevent/reduce the front wheels intruding on the cab in an offset front end collision. The lower part of the mount is made of 780MPa ultra high strength steel (highest strength steel used in the frame).

Roger - Makes sense in stock configuration...

 

[harper7]

Roger - Makes sense in stock configuration...

Makes sense in any configuration.:nod:
I chopped too but just the front part that was rubbing on mine.
Meant to help protect and absorb some of the energy in a overlap crash like this would be my guess on why they used such high strength steel....
In slow mo ,looks like it deflects the truck away when it get to about that mount.
<iframe width="560" height="315" src="https://www.youtube.com/embed/q70jNH-FnVY" frameborder="0" allowfullscreen></iframe>

 

[Randyman...]

Roger - Makes sense in stock configuration...

Makes sense in any configuration.:nod:

Absolutely agree - Was just being tongue-in-cheek with regard to its effects on larger tires and the need to cut it out It was obviously not engineered with much larger tires in mind (why should it be, right?).

 

[rrueizhig]

I will consider this diy if I happen to get excess rubbing from larger tires.

 

[alfonzo]

Thanks. I will show this series of pics to my fabricator.

 

[RaginTxn84]

Any reason to cover the chop instead of just leaving it open/exposed? I would think you would paint where you cut, but does the welded plate really make a difference other than aesthetics?

 

[1engineer]

Any reason to cover the chop instead of just leaving it open/exposed? I would think you would paint where you cut, but does the welded plate really make a difference other than aesthetics?

Strength.

 

[TheWraith]

thank you for the pics .... going to have gears and this done in July ... Thank you

 

[Jono.ful]

those crash test vids are horrifying. I was seriously considering doing the chop, but I think I'll hold off now.

 

[wfo9]

those crash test vids are horrifying. I was seriously considering doing the chop, but I think I'll hold off now.

Everyone should make their own decision... but

The body mount chop is 0 risk compared to a lift. If you want to see something scary, look at the rollover propensity with a lift. That at least has physics behind it vs pure speculation

If you want it 100% safe... don't touch it or add anything or even carry anything in the back ever.

 

[rochmpr]

Everyone should make their own decision... but

The body mount chop is 0 risk compared to a lift. If you want to see something scary, look at the rollover propensity with a lift. That at least has physics behind it vs pure speculation

If you want it 100% safe... don't touch it or add anything or even carry anything in the back ever.

Live in a bubble, but that's no fun. Lift it, cut it, wheel it and live!

 

[Jono.ful]

Everyone should make their own decision... but

The body mount chop is 0 risk compared to a lift. If you want to see something scary, look at the rollover propensity with a lift. That at least has physics behind it vs pure speculation

If you want it 100% safe... don't touch it or add anything or even carry anything in the back ever.

avoiding a roll over has a lot to do with the skill of the driver and their propensity for taking evasive action, whereas a front end collision such as those shown in the vids harper posted may be completely unavoidable

 

[TheWraith]

avoiding a roll over has a lot to do with the skill of the driver and their propensity for taking evasive action, whereas a front end collision such as those shown in the vids harper posted may be completely unavoidable

we are not promised tomorrow. And I dont see how skills come into play in a roll over.

Its like gun play. How sure are you; that this is how your going to react to an emergency... when you dont practice your gun handling skills under high stress ???

Are you there actually practicing your driving skill to stop a roll over ???

 

[wfo9]

avoiding a roll over has a lot to do with the skill of the driver and their propensity for taking evasive action, whereas a front end collision such as those shown in the vids harper posted may be completely unavoidable

I have to totally disagree. Many rollovers have nothing to do with lack of driver skill, they are just as unavoidable as any other type of accident. SUVs like the 4Runner just have a very high propensity to rollover compared to other vehicles with a lower center of gravity, lifting it makes it much worse. Once there is impact... all bets are off.

I hate to tell you this, but you made your 4runner much less safe by lifting it.

Then again, live a little and don't worry about it.:banana: