Panhard drop bracket option?

[Casual Cruiser]

I’m curious. What would be the pros and cons of dropping the frame side of the Panhard bar instead of raising the axle side? There may be an obvious answer to this, but I’ve searched around a bit and haven’t found a clear answer. Thanks so much for your time.

 

[jkeithw]

was that for me, or DR?

 

[4gotalot]

Ok here’s the damage report. Lol also yeah I kinda exaggerated the frame damage . For some reason the last time I looked (baja and super dirty ) I guess it was just real dirty. There’s basically a ding. I fully used the bracket as a bump stop over many many miles down in baja with confidence based off data in the jeep, ram and 4runner world. We have sold prob over 25k brackets or more. s*** I’ve sold about 5k 4runner brackets in the last 1.5 years !! It’s truly been a blessing !!
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And the shorty in a Red.

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Whoever has the closest bday to me I will give the hold standard height version I just took off away. You can always just cut off the top and then paint it !

Dec2nd. Game on!!

I have kept up with all and every post over time trying to learn but I do not type very well so just read mot of the time. I just went out and cked and I have 20" on the fixed end (L) and 16.5" on the axle mount = 3.5" This may explain driving manners that I was blaming on my heavy tires. Lift is in my sig below.

I hope my DOB of Aug 20 gets me back on track.

 

[TLC2013]

hey, sorry - haven't had a lot of SM or forum time this year, so I've missed some tags around here.

Yep, there is not a lot of overhead clearance on this platform compared to other Toyota models—it sort of tells you what the company's use projections were, considering they expect these to carry some load more or less daily. Position-wise, it's a fine line between kissing the cross-member without extending bump stops and missing the coil if the mount were angled to slide past the cross-member. (I like that you've retained the inner coil bumps, btw - I retain those as well as they don't really interfere with articulation but improve bottoming on square hits.)

Design-wise, I have to deal with some compromise here to get a height-adjustable (and therefore tunable for different loads/setups) part, so this variant is shaved down as much as I feel comfortable with while retaining both mounting heights. In this scenario, you could trim the rearward ear to clear, but I'd probably leave it as-is now that it has found and defined its operating space unless it bothers you, so as to retain the upper hole option if you ever change it up suspension-wise. From what I can tell, it doesn't look like the in-use contouring you've done there has limited the movement of the joint.

The installation looks good.

Are /were you getting any noise on contact that you're aware of?

The bracket has been great, appreciate the R&D to bring this to the 200 series, as it's a niche market in comparison to the other 4x4 toyota platforms. I never even new it was making contact, no noise or anything to report. I came across the contoured top incidentally during some other suspension maintenance.
No limit of travel, my 34" tires are making contact with the fender well at full compression/articulation on both sides.

 

[jkeithw]

@TLC2013 glad you like it!

 

[Casual Cruiser]

was that for me, or DR?

A general curiosity. Wasn’t directed at anyone in particular. Am considering the shorty and after reading about the contact started thinking about the other option of dropping the frame side. Has this been done before?

 

[jkeithw]

A general curiosity. Wasn’t directed at anyone in particular. Am considering the shorty and after reading about the contact started thinking about the other option of dropping the frame side. Has this been done before?

the quick & dirty answer is dropping the frame side lowers the rear roll center - and exacerbates the "tippy" feel of the top-heavy SUV body.

 

[drkdss]

A general curiosity. Wasn’t directed at anyone in particular. Am considering the shorty and after reading about the contact started thinking about the other option of dropping the frame side. Has this been done before?

Edit: what he said

It has to do with the “ roll center”. Lower you go on the frame side. It can start to feel like it wants to roll over !

 

[Casual Cruiser]

the quick & dirty answer is dropping the frame side lowers the rear roll center - and exacerbates the "tippy" feel of the top-heavy SUV body.

Thanks for your response. I can totally see that happening. My only curiosity was Toyota decided to keep the axle side almost perfectly in line with the center of the axle and dropped the frame side down. So in their minds, they were willing to exacerbate the role center of the body, but keep the left, right Pressures on the axle centerline of the axle. It would be interesting to talk with the engineers who made that choice. They easily could’ve raised the panhard up to reduce the tippy feeling of the body, but increase the Torsional moments on the axle. I guess if I had superior fabricating skills, I would go in and try both options and do a number of tests. That would be another life. Thank you for your time.

 

[jkeithw]

Thanks for your response. I can totally see that happening. My only curiosity was Toyota decided to keep the axle side almost perfectly in line with the center of the axle and dropped the frame side down. So in their minds, they were willing to exacerbate the role center of the body, but keep the left, right Pressures on the axle centerline of the axle. It would be interesting to talk with the engineers who made that choice. They easily could’ve raised the panhard up to reduce the tippy feeling of the body, but increase the Torsional moments on the axle. I guess if I had superior fabricating skills, I would go in and try both options and do a number of tests. That would be another life. Thank you for your time.

I think Toyota was expecting the LC to be used primarily by the luxury market after the 80-series, personally, and the chassis decisions seem to reinforce that.

From what I can tell, Toyota certainly didn’t intend for these to be lifted. An indication of what the factory might’ve done had it considered increased ride height for this platform might be found in the differences between 3rd-gen and 4th (and later) 4Runner models, wherein the factory designed-in a small body lift and additional height to the axle-side panhard mount.

Raising the sprung mass of the vehicle and then lowering the rear roll center wouldn’t be moving toward restoring factory geometry or characteristics, IMO.

When I first started offering my product to the 4Runner crowd, I called it “Panhard correction” because it is an effort to restore factory geometry after lifting (and improve upon it, when possible). At the time, the aftermarket wasn't addressing those geometry changes, except for a single Panhard drop bracket product for the 3rd gen that did the opposite of what I think is needed.

For what it's worth, though, I say give it a shot—you can always add a temporary frame-side drop for testing and cut it off later if you don’t like it.

In fact, reversibility is built into my PCK®s by intentionally retaining the factory holes. On platforms that get both axle and frame-side brackets as part of their kits, one can do just what you are proposing—for testing purposes—if one wants to. (My 100 & 200-series PCK®s would include a frame-side bracket - like the 80-series variant does - if the typical lift heights were taller and not limited by the front suspension.)

 

[Casual Cruiser]

I think Toyota was expecting the LC to be used primarily by the luxury market after the 80-series, personally, and the chassis decisions seem to reinforce that.

From what I can tell, Toyota certainly didn’t intend for these to be lifted. An indication of what the factory might’ve done had it considered increased ride height for this platform might be found in the differences between 3rd-gen and 4th (and later) 4Runner models, wherein the factory designed-in a small body lift and additional height to the axle-side panhard mount.

Raising the sprung mass of the vehicle and then lowering the rear roll center wouldn’t be moving toward restoring factory geometry or characteristics, IMO.

When I first started offering my product to the 4Runner crowd, I called it “Panhard correction” because it is an effort to restore factory geometry after lifting (and improve upon it, when possible). At the time, the aftermarket wasn't addressing those geometry changes, except for a single Panhard drop bracket product for the 3rd gen that did the opposite of what I think is needed.

For what it's worth, though, I say give it a shot—you can always add a temporary frame-side drop for testing and cut it off later if you don’t like it.

In fact, reversibility is built into my PCK®s by intentionally retaining the factory holes. On platforms that get both axle and frame-side brackets as part of their kits, one can do just what you are proposing—for testing purposes—if one wants to. (My 100 & 200-series PCK®s would include a frame-side bracket - like the 80-series variant does - if the typical lift heights were taller and not limited by the front suspension.)

Thanks, this is really good information. The fact that Toyota raised the axle side on the forerunner gives more insight into their thinking. Thank you for your contribution to IH8MUD and taking the time to entertain my question.

 

[jkeithw]

Thanks, this is really good information. The fact that Toyota raised the axle side on the forerunner gives more insight into their thinking. Thank you for your contribution to IH8MUD and taking the time to entertain my question.

no problem, I love this stuff.

 

[TeCKis300]

Thanks for your response. I can totally see that happening. My only curiosity was Toyota decided to keep the axle side almost perfectly in line with the center of the axle and dropped the frame side down. So in their minds, they were willing to exacerbate the role center of the body, but keep the left, right Pressures on the axle centerline of the axle. It would be interesting to talk with the engineers who made that choice. They easily could’ve raised the panhard up to reduce the tippy feeling of the body, but increase the Torsional moments on the axle. I guess if I had superior fabricating skills, I would go in and try both options and do a number of tests. That would be another life. Thank you for your time.

There is a bunch of trades and considerations. Packaging is always a part of this and it could be they needed to maintain clearance on the axle side against the vehicle frame. Having a minor lever arm on the axle with the PCK bracket isn't the worst thing. Extending the chassis side down with an increased lever arm is a trade also.

Sagitta and roll center are primary considerations. Ideally the point which the panhard crosses the vehicle center line, overlaps with the vehicle roll center, to maximize roll resistance. As the roll center of the vehicle is raised, it creates a delta which is what the PCK is correcting also correcting for.

Looking at the overall vehicle, more modern Toyota's have the benefit of additional roll resistance with KDSS, AHC, disconnecting sways, etc. that they don't rely only on panhard roll center. To @eimkeith 's point, moving the panhard towards restoring original design geometry is a good thing.

 

[Casual Cruiser]

There is a bunch of trades and considerations. Packaging is always a part of this and it could be they needed to maintain clearance on the axle side against the vehicle frame. Having a minor lever arm on the axle with the PCK bracket isn't the worst thing. Extending the chassis side down with an increased lever arm is a trade also.

Sagitta and roll center are primary considerations. Ideally the point which the panhard crosses the vehicle center line, overlaps with the vehicle roll center, to maximize roll resistance. As the roll center of the vehicle is raised, it creates a delta which is what the PCK is correcting also correcting for.

Looking at the overall vehicle, more modern Toyota's have the benefit of additional roll resistance with KDSS, AHC, disconnecting sways, etc. that they don't rely only on panhard roll center. To @eimkeith 's point, moving the panhard towards restoring original design geometry is a good thing.

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I love the thought you put into these details. Theoretically we could raise the Panhard bar until the Delta was zero. This would mean, at least the rear of the car body wouldn’t experience roll. I understand that your luggage capacity may be diminished as the Panhard bar would probably be up in the back luggage space somewhere. I wonder how the axle would react with that large of a moment arm on it? Not really a serious question but more of an engineering gymnastics.

 

[Boston Mangler]

There is a bunch of trades and considerations. Packaging is always a part of this and it could be they needed to maintain clearance on the axle side against the vehicle frame. Having a minor lever arm on the axle with the PCK bracket isn't the worst thing. Extending the chassis side down with an increased lever arm is a trade also.

Sagitta and roll center are primary considerations. Ideally the point which the panhard crosses the vehicle center line, overlaps with the vehicle roll center, to maximize roll resistance. As the roll center of the vehicle is raised, it creates a delta which is what the PCK is correcting also correcting for.

Looking at the overall vehicle, more modern Toyota's have the benefit of additional roll resistance with KDSS, AHC, disconnecting sways, etc. that they don't rely only on panhard roll center. To @eimkeith 's point, moving the panhard towards restoring original design geometry is a good thing.

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#nerd

This is why i call you a friend sir!

 

[TeCKis300]

#nerd

This is why i call you a friend sir!

Excuse my nerding out. It's an illness.

 

[Endurbro907]

Installed one of the Dr KDSS brackets after binge reading this thread, I feel like an idiot for not doing it sooner. Absolutely cleaned up that weird little "wag/wiggle/instability" I was feeling and brought it back to that factory planted feel. For those debating, I'm on an OME nitro charger setup with the shim spacers and 34s, used the top hole as I don't run super heavy most of the time (not towing much anymore), just some ADGU drawers in the rear.

If you're on the fence, strongly recommend, truly the best ~$200 I've spent in a while on the truck.

 

[FerrisBueller]

Trimmed and painted my BOTCK so it would no longer make contact with the frame. You can see the witness marks where contact was happening (one major, one minor, right next to each other).

 

[Boston Mangler]

Trimmed and painted my BOTCK so it would no longer make contact with the frame. You can see the witness marks where contact was happening (one major, one minor, right next to each other).

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Thanks for posting this.

So is this basically the “shorty” version of the bracket now?

Placing an order shortly

 

[FerrisBueller]

Thanks for posting this.

So is this basically the “shorty” version of the bracket now?

Placing an order shortly

Yes, I basically cut mine down to match the "shorty".