Just got back from rock crawling with a Jeep club in Big Bear, Ca. I got the 4Runner Trail to replace my 1998 Isuzu Trooper. The Trooper had a more rigid chassis and better clearance of the frame. I do like the 4Runner but the KDSS protection plates really ruin the front clearance. Having that low assembly out front makes climbing boulders difficult. Not sure the trade off for KDSS is worth the limiting factor.
KDSS- flaw?
- Thread starter BrockT
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adkinsadam1
New member
What low assembly are you talking about? Do you have any pics?
iDRiVaT4R
New member
If you hit the front skid on something, You'll gain a little more clearance, I know I did. LOL
But yeah, that is the biggest drawback, having the front skid that low to accommodate the KDSS Piston's travel.
Some day I want to get Bud Built Skids, they are TUFF!! Haven't heard if Bud finished the front skid yet for the KDSS equipped 4Runner's, but I know the rest are already available.
But yeah, that is the biggest drawback, having the front skid that low to accommodate the KDSS Piston's travel.
Some day I want to get Bud Built Skids, they are TUFF!! Haven't heard if Bud finished the front skid yet for the KDSS equipped 4Runner's, but I know the rest are already available.
iDRiVaT4R
New member
I think he is talking about the front skid as you can see in my pic, it hangs really low to allow the piston travel. As you can see mine is beat up a little.
JB.
New member
Look at the 4th pic down in this thread.
http://www.toyota-4runner.org/5th-gen-t4rs/57878-2010-canadian-4runner.html
adkinsadam1
New member
This is a photo I took measuring the ground clearance of a 4runner Trail with KDSS. I see no evidence of a skid hanging low. And if this is as low as you are talking then you are crazy! 10" stock is fantastic!
Egstyle
New member
I found that a lift makes a world of difference as far as front clearance goes. Now I feel like the bumpers are the limiting factors (for approach and departure angles), along with the long wheel base when it comes to crawling. A stock TE is good for dirt trails, sand, loose rock, and mud, provided you put on some decent tires. It is not good for rock crawling without getting some damage. I definitely felt limited in a stock-height TE.
iDRiVaT4R
New member
The low section is seen in my pic above where the piston is. I think the non KDSS skid plate has a better angle, doesn't stick down as far.
harper7
Senior Member
I've lifted both ,Mine without and one with KDSS and front skid plate dips down just a little more then the non-KDSS. I had my oem skid plates off already and matched them up when I took the KDSS one off. That's why Bud had to redesign the front skids to accomodate the lower KDSS sway bar position.
Not that big of deal. The OP just needs to get a 3/2 lift and bigger tires to run with the big dogs!
Here is iDRIVaT4R's paint chopped pic to show it.
Not that big of deal. The OP just needs to get a 3/2 lift and bigger tires to run with the big dogs!
Here is iDRIVaT4R's paint chopped pic to show it.
Thai
Elite Member
Trooper having a MORE rigid chassis??!! Really? You're talking about frame flex, right? I was a big fan of the Trooper back in the day, but I never thought that its frame could be stronger than the 5th gen's. If that is the case, then Toyota needs to do better. I know that the FJ had some off-roaders complaining about excessive frame flex, which may have contributed to the infamous "fender bulge/tear." I assumed that Toyota surely has fixed this with the 5th gen.
T4Fun
Banned
this video doesnt give me a lot of confidence about any frame toyota makes. Toyota needs to get its act together. The GX will likely be our LAST toyota for that matter. WTF, tundra is supposed to be best of the breed. Is frame on toyota less rigid for crash impact dissipation or what? AS for your comment on the FJ, the FJ, GX and 4R all have the same frame, so how did they fix what youre referring to on the 5th?
YouTube - Ford F150 vs Toyota Tundra - Frame Strength
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Thai
Elite Member
I believe that video is of the previous Tundra frame vs the current gen F150. Of course, the current Tundra frame is still C-channels in the mid & rear sections. The tundra frame is boxed in the front where the cabin is...so, crash protection should be adequate. The main issue with is with what is behind the cabin, which affects towing/load durability.
Watching the Ford video makes me miss my G-wagen frame! If you ever want to see a robust frame,check out the Mercedes G!
It is called resonance frequency. Basically, hitting those bumps (at a certain pattern) at a certain speed puts the suspension at a natural frequency where the amplitude of the vibrations rapidly increases. I'm sure that there is a resonance frequency for the F150 frame and suspension as well. I think another reason the Tundra is prone to that is the fact that Toyota set the suspension up to drive and handle well when fully loaded. The rear is bouncy and skittish unloaded. With a full load, it settles nicely and probably drives much better than the trucks that have their suspensions tuned with no load. There are trade-offs with every engineering decision. Finally, the video is put out by Ford. Do you expect them to be fair and balanced and not sandbag?
I don't buy "fully boxed" as being a requirement for a rigid frame, either. The heavy duty trucks from the big 3 aren't fully boxed. Plus, if you've taken any material science course, C channel can be as strong as box tubing. It is all about the design of the segment. One isn't automatically better than another especially if weight, NHV, and handling are a consideration.
Sometimes deflection in a structural member is a good thing for the overall goal of the design. The wingtips of airplanes flex upward and are designed that way to keep the wing spar from being way too heavy. If you look at a large industrial trailer, they typically bow upward in the center so they flatten out when loaded.
<--- mechanical & aerospace engineer
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Thai
Elite Member
Given equal materials, i rather have boxed frame over C-frame anyday of the week! I understand that bigger trucks use C-frames, but i wonder if this is more because of cost than actual usefulness of using such a design. The HD trucks have huge frames...and to boxed them and then have thru-&-thru crossmembers, i would imagine that it would be quite costly, in both materials and construction.
The non-HD trucks used to have C-frames...not anymore. Dodge, Ford, and Chevy all use fully-boxed frames now...ONLY Toyota does not in any of their trucks. Those big boys have been designing trucks for a long time.
Even the HD trucks are starting to come around...check out the new 2011 Chevy Silverado HD. Here is an excerpt:
"The most important change to the Silverado this year is the frame — going from a full-length C-channel design to a fully boxed frame with through-welded cross members. The frame is five times times stiffer in twisting, 92% stiffer in bending, 20% stiffer in beaming and the front subframe is 125% stiffer by itself. The rear suspension has also been upgraded, now with offset leaf springs that have more spring behind the axle than ahead of it, which works to reduce axle hop under loaded take off."
The 2010 Silverado HD frame was not exactly made of noodles mind you....
Thai
Elite Member
Either way, if the 4runner frame flexes more than a Trooper, then i am sorely disappointed. I doubt it though. But anything is possible these days...FJ owners have been complaining about frame flex for a long time...and we see a few issues with engine mount/crossmember breaking off on 4th gen 4runners.... :moping:
If you believe that engineering decisions are never made on marketing, you're being naive. If 70% of the people in their marketing research said that they felt the truck should have a fully boxed frame, it will be fully boxed come redesign.
The 4Runner is fully boxed from my understanding... and some guy on the internet said it is flexier than a Trooper, OMG!
BTW, cross bracing carries way more weight in the stiffness game than the channel cross section.
Tell me this: If the last Silverado was stiff enough to do the job (and by every account, it probably was), would you want them to increase the stiffness of the frame? There IS a weight penalty (or cost penalty) that comes with extra stiffness without resorting to some exotic materials or process for construction. Would you carry around an extra 400lbs of weight for extra stiffness that is going to make the truck marginally better in some 'at the limit' condition?
That is exactly why I don't get wrapped around the axle about one frame being stronger than the next (what marketing touts, particularly). If it is reliable and does the job, who cares about marketing numbers? People on here have put the 4Runner through way worse things than I'll ever see without problems. Without seeing the exact finite element analysis of the different frames, it seems like a moot point and mostly marketing speak to me. Engineering these things is a fine line of capability, cost, and weight. I'm not going to pretend to know what is the best channel to use on a truck frame because I don't know their exact calculations. I mean, the Tundra is fully boxed until the rear section. There was probably a reason the engineers designed it that way... I doubt they just forgot they boxed everything else. haha
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Thai
Elite Member
Quentin, i guess that i like things to be overbuilt for the purpose, rather than "just" making it. I like to be on the safe side, just in case, i accidentally go to the limit with my truck. And BTW, this may surprise you, but i know of a few farmers where i work that go well above the "published" limits with their work truck! So, yeah, it DOES matter to many other folks.
When did i imply that decisions are never based on marketing? Did you even bother to read my other posts in this thread?
Cross-bracing...well, uhhh, the Chevy and Ford have superior cross-bracing to go along with the fully boxed frame.
Actually, the Tundra is boxed only on the front part where the cabin is. The middle and rear sections are C-framed. Given that the Tundra has some other goodies (nice V8, nice interior design, etc.), the engineers may have well compromised on the frame to keep cost competitive. To me, that is the worst place, but YMMV.
And while many 4runner owners have gone far off-roading, it is not without cost: http://www.toyota-4runner.org/4th-gen-t4rs/50242-uh-oh-my-frame-cracked.html or http://www.toyota-4runner.org/fj-cruiser/50066-more-trouble-fj-cruiser-frame-buckling.html
When did i imply that decisions are never based on marketing? Did you even bother to read my other posts in this thread?
Cross-bracing...well, uhhh, the Chevy and Ford have superior cross-bracing to go along with the fully boxed frame.
Actually, the Tundra is boxed only on the front part where the cabin is. The middle and rear sections are C-framed. Given that the Tundra has some other goodies (nice V8, nice interior design, etc.), the engineers may have well compromised on the frame to keep cost competitive. To me, that is the worst place, but YMMV.
And while many 4runner owners have gone far off-roading, it is not without cost: http://www.toyota-4runner.org/4th-gen-t4rs/50242-uh-oh-my-frame-cracked.html or http://www.toyota-4runner.org/fj-cruiser/50066-more-trouble-fj-cruiser-frame-buckling.html
