Gas Pedal Flex Solution

17Denali · February 5, 2017

Don't see the need for all the performance of banging head and eyes rolling but I guess some people can't help themselves from being so rude it was a simple question. All kinds of vehicles including big trucks have things on the firewall that are related to pedals inside but I guess not these trucks as a new owner I didn't know that. Maybe grow up !!

dorkweed · February 5, 2017

Don't see the need for all the performance of banging head and eyes rolling but I guess some people can't help themselves from being so rude it was a simple question. All kinds of vehicles including big trucks have things on the firewall that are related to pedals inside but I guess not these trucks as a new owner I didn't know that. Maybe grow up !!

Did you even read the prior pages of the thread??? If not; shame on you for asking such an inane question.

GMC2015 · February 5, 2017

I was at a dealer yesterday and noticed this gas pedal flex is still on the 2017s. GM should've done something by now.

roadkill5.3 · February 5, 2017

i see this alot. people asking dumb questions and what not. somethings take a few seconds of actually looking, and feeling around. i wasnt sure where to put the shim myself, and i didnt read much at all. i went outside, checked it out, felt in and around it, and found the gap on the bottom bolt, between the bracket and the firewall. wiggled it and verified that was the gap that wiggles.and shimmed it

not worth the bashing, but sometimes you just have to get off the couch or chair, and look yourself.

ChevyTech77 · February 5, 2017

In addition to the sloppy throttle response, I had an issue related to the strange mounting system of the Silverado gas pedal. About a month ago the pedal began to squeak like crazy. The dealer contacted GM and said they had run into this numerous times. If you get a pedal squeak this mounting design is the culprit. BTW the dealer used double sided tape (they said) to fix it. Regardless it is now quiet and the throttle seems to function right.

All they had to do is seat the carpet retainer that was rubbing the edge of the pedal plate and the noise would go away. I trimmed mine so that if it ever did back off a little, it couldn't rub and make the noise.

I can't believe the GM Engineering and Design Team's would approve of such a flimsy mounting bracket for this important part of basic motor vehicle operation.

I would love to have GM explain why this is "as designed" and "normal" to have this amount of accelerator bracket flex.

I also realize this flex issue is NOT the entire acceleration lag issue that so many have complained about but this would be a chance for GM to step-up to the plate and correct a basic design flaw on our trucks.

I can't believe over time and usage this bracket will fail as currently designed.

Sure I could shim and install additional hardware to correct this safety issue, but really GM, please fix our trucks.

It's engineered correctly, nothing to fix.

I agree that a good video would be worth a million words of what the problem is and where it's located.

I filed the NHTSA complaint shown below:

VEHICLE SPEED CONTROL: 2014 Chevrolet Silverado

Filed: 12/26/2014

WHILE MOVING FROM A STOP THE TRUCK SOMETIMES LAGS IN ACCELERATION WHICH MAY CAUSE THE OPERATOR TO DEPRESS THE ACCELERATOR FURTHER THAN REQUIRED TO ENTER TRAFFIC. THIS CONDITION ALSO MAY CAUSE A SHORT ACCELERATION DELAY WHEN PULLING INTO TRAFFIC THAT CAN BE UNEXPECTED BY THE OPERATOR. I HAVE BEEN SURPRISED MANY TIMES BY THIS OPERATOR DISCONNECT ACCELERATING FROM A STATIONARY POSITION. AFTER DRIVING MY NEW TRUCK 900 MILES I INVESTIGATED THE ACCELERATOR PEDAL ASSEMBLY BRACKET TO FIND THAT THE ENTIRE BRACKET IS NOT PROPERLY FASTENED STRUCTURALLY TO THE FIRE WALL BY DESIGN. I INSPECTED MY TRUCK ON 12/23/14 AND FOUND THIS PROBLEM, THE ACCELERATOR PEDAL BRACKET FLEX ON MY TRUCK LOOKS TO BE ~3/4" TO 1" BEFORE THE ELECTRONIC LINKAGE ENGAGES. THE PEDAL TIP-IN ENGAGEMENT HAS TO FLEX THE MOUNTING BRACKET BEFORE THE ELECTRONIC ACCELERATION SWITCH ENGAGES. I CAN'T BELIEVE THE GM ENGINEERING AND DESIGN TEAM'S WOULD APPROVE OF SUCH A FLIMSY MOUNTING BRACKET FOR THIS IMPORTANT PART OF BASIC MOTOR VEHICLE OPERATION. I FEEL OVER TIME AND USAGE THAT THIS BRACKET MAY COMPLETELY FAIL AS CURRENTLY DESIGNED. I COULD SHIM AND INSTALL ADDITIONAL HARDWARE TO CORRECT THIS SAFETY ISSUE, BUT I FEEL THIS DESIGN ISSUE SHOULD BE ADDRESSED WITH GM BEFORE SOMEONE HAS A CRASH OR WORST.

How'd that turn out for you?

This needs to be a sticky because holy hell it made such a massive difference fixing that freaking pedal bracket flex!!!!

It drives like a totally different truck!

Side note, what the F were they thinking with that design?! Big TY to OP & the replies. This plus disabling AFM has made me soooo much more satisfied with the truck. My thoughts on a tune are now on the back burner, I honestly have darn near no complaints with the shifting & throttle response now, before these 2 simple mods it was almost scary to drive sometimes due to the hesitation & unpredictable, lazy pedal.

Vibration control. That's what they were thinking. One of the many complaints about AFM equipped 900 Series trucks was vibrations through the gas pedal when the engine was in afm mode.

I have no idea why GM hasn't addressed this simple issue in the 3rd model year. If they want the throttle to respond slowly for enhanced fuel economy, it seems to me that should be done in the throttle mapping and not by having the accelerator bracket have a half inch of slop in it.

See previous reply. This pedal bracket mounting is used on many GM vehicles for the same concern. I've never seen one complaint until I read this thread.

GM didn't intentionally design the bracket to flex for improved fuel economy. It's just a cheap design that allows flex and hampers accurate throttle control. The true source of the unresponsive throttle is the drive-by-wire system in conjunction with torque management:

"The 5.3L, and 6.2L suffers from poor throttle response down low. In fact the factory programming has limits on the max throttle blade opening that PCM allows and is based on RPM range engine is operating in. By correcting this issue and a few others; improvements will be much better throttle response, step on go pedal, vehicle will respond quickerthis DBW system is a torque driven system, it works by taking a certain amount of torque via engine and wheel and applies it to what the driver foot say it needs; a better way to explain it is its a torque limiter. It only allows so much torque at a given pedal position. Stock tables are conservative and numb at best and thats why one would feel some times a lag or a goofy pedal with DBW systems. For a 5.3L, or 6.2L V8 this is one of the most critical areas that must be addressed and modified to generate more torque /hp and throttle response."http://5startuning.com/got-a-gmgmc/

The pedal flex eliminates some of the vagueness of the throttle but only a tuner can make your truck truly reponsive and "torquey" off the line.

Incorrect. Read above.

HondaHawkGT · February 6, 2017

Incorrect. Read above.

Oh? Incorrect on which part?

The throttle response is pretty terrible with the factory PCM programming. Guys in this thread are naturally trying to find a simple explanation for why a truck with a 5.3 rated at 355HP and 383 lb-ft torque seems so dead from a stop. The flexible pedal bracket is going to be an easy target to blame, correct or incorrect.

GM's truck would get better reviews if they would just tune the truck right.

Edited February 6, 2017 by HondaHawkGT

ChevyTech77 · February 6, 2017

Oh? Incorrect on which part?

The throttle response is pretty terrible with the factory PCM programming. Guys in this thread are naturally trying to find a simple explanation for why a truck with a 5.3 rated at 355HP and 383 lb-ft torque seems so dead from a stop. The flexible pedal bracket is going to be an easy target to blame, correct or incorrect.

GM's truck would get better reviews if they would just tune the truck right.

You didn't read my explanation, above your post that I quoted, I see.

My '14 5.3 runs almost as hard as my '11 and '13 6.2's did, especially on E-85, if driven right. I've never heard of anyone blaming the amount of torque management in these trucks on the flexible pedal mounting bracket. I get what it's doing and what is being discussed here but the K2 engines have more torque management programmed into them that any of the 900 Series trucks had. Saying that GM intentionally made the pedal bracket flexible for fuel economy or for more torque management, especially to the point of trying to sue GM for it is some of the craziest things I've read in a long time. Again, I posted the exact reason why GM did what they did with the pedal bracket. You can believe it or not, I'm not going to argue with you. I've worked deep within "the house" for 10 years and I'm not here to brag about what I know or throw it in anybodies face but sometimes people on forums make my head hurt.

I guess all I had to do is come back here, after a long hiatus, to read something like this. One of the many reasons why I quit reading/posting/contributing here.

HondaHawkGT · February 6, 2017

You didn't read my explanation, above your post that I quoted, I see.

My '14 5.3 runs almost as hard as my '11 and '13 6.2's did, especially on E-85, if driven right. I've never heard of anyone blaming the amount of torque management in these trucks on the flexible pedal mounting bracket. I get what it's doing and what is being discussed here but the K2 engines have more torque management programmed into them that any of the 900 Series trucks had. Saying that GM intentionally made the pedal bracket flexible for fuel economy or for more torque management, especially to the point of trying to sue GM for it is some of the craziest things I've read in a long time. Again, I posted the exact reason why GM did what they did with the pedal bracket. You can believe it or not, I'm not going to argue with you. I've worked deep within "the house" for 10 years and I'm not here to brag about what I know or throw it in anybodies face but sometimes people on forums make my head hurt.

I guess all I had to do is come back here, after a long hiatus, to read something like this. One of the many reasons why I quit reading/posting/contributing here.

Sorry if I come off as trying to brag or act as if I have all the answers. I definitely don't. I'm also not trying to start an argument over some4hing as stupid as the throttle bracket. It makes complete sense that the bracket is designed to float away from the firewall to isolate AFM vibration. The idea of filing a lawsuit over it is indeed ridiculous.

A lot of guys that don't have a technical background come here to figure out why the first 15-20% of pedal movement produces barely enough engine power to pull out into busy traffic. It's something that bothered me since most of the previous vehicles I owned were cable throttles. The 5.3 make a lot of power but I guess GM thinks you should really have to goose the throttle to make that power.

Edited February 6, 2017 by HondaHawkGT

Waymon · February 6, 2017

Well that escalated quickly

Sent from my iPhone using Tapatalk

ChevyTech77 · February 6, 2017

Sorry if I come off as trying to brag or act as if I have all the answers. I definitely don't. I'm also not trying to start an argument over some4hing as stupid as the throttle bracket. It makes complete sense that the bracket is designed to float away from the firewall to isolate AFM vibration. The idea of filing a lawsuit over it is indeed ridiculous.

A lot of guys that don't have a technical background come here to figure out why the first 15-20% of pedal movement produces barely enough engine power to pull out into busy traffic. It's something that bothered me since most of the previous vehicles I owned were cable throttles. The 5.3 make a lot of power but I guess GM thinks you should really have to goose the throttle to make that power.

Actually if you roll the throttle, torque management doesn't jump in and whoa things up so much. Try and drive it aggressively and it's a pooch. I learned that with my 6.2's.

cbrsilv15 · February 6, 2017

It's simple. Drive an older truck and feel how responsive the has pedal is. Drive a 14+ and feel the ridiculous pedal travel. Shove something behind the pedal to stop flex, and problem solved.

roadkill5.3 · February 6, 2017

i just drove my truck around, and what a difference and no vibration..feels as responsive as my 05 duramax without the tq obviously. very nice to drive..

if i had no warranty id have efilive done to wake it up more, but for now, this made a big difference and im happy how it gets up. especially since it took a ****ing panters stick. kind of hacky but hey, screw it.

Edited February 6, 2017 by jgreen2193

FL335i · February 7, 2017

Not worth arguing over. Just put a paint stick or two behind it and enjoy. Only God knows why GM designed it this way. Even if we knew, would it change anything, no. I own four GM's, two late model and two from the mid 80's and let's face it. Gm products are not.... well... not precision built machines. But it's OK, we still have great V8's and a very work-able truck. My wife's enclave is great for the family vehicle. I'm sure if the K2XX was built like a E39 BMW it would cost a fortune, or they would have to move the assembly plant further south, from Mexico to Guatemala. Kinda funny, my K5 Jimmy doesn't have any gas pedal issues Speaking of which, I'm going to tinker on it now, you guys continue to bicker.

Edited February 7, 2017 by FL335i

zal15lt · February 7, 2017

i went outside, saw the flex, went inside, got a painters stick, broke it in 2 pieces 1" long, wedged under the gap on the bottom, holy shit, i cant believe it. i have motorized pedals 2016 1500. there is more play left and right and a little front and back on the assembly. but now there feels like there is no more play at all.

thanks for upping this thread where i would see it. when i see you at the bar, ill buy a round!

You have a pic of where you placed your shims?

I want to do this to my '15 and want to be sure I'm

placing them in the correct spot for the adjustable pedals.

Thanks

sk · February 7, 2017

You have a pic of where you placed your shims?

I want to do this to my '15 and want to be sure I'm

placing them in the correct spot for the adjustable pedals.

Thanks

It's in the very first post ....