Touchy Throttle Accelerator Pedal Adjustment

[Rick2004LJ]

Kind of resurrecting an old thread - wanted to update what we have tried, warn about some mistakes, and get other ideas/opinions.
Old thread - https://wranglertjforum.com/threads/touchy-throttle-response.14314/

2004 Unlimited Auto trans - I had issues with throttle response. It seemed like there was slack/slop in the throttle linkage which made it difficult to smoothly apply power, especially when crawling etc. Per much advice on previous thread, I assumed it was just a function of getting used to it, training/muscle memory for the right foot. Put in 50+ hours on the trail, but it only got marginally better.

Mechanic suggested to replace the throttle linkage (even though existing looked fairly new and in good shape) which we did. No change. Mechanic (not a Jeep specialist) was a bit baffled by the amount of travel the throttle pedal has before starting to engage. He suggested we try shortening the cable a little bit and we tried it. Here were the results:

Good - MUCH better throttle response, much easier to maintain smooth power especially when bouncing around on the trails. Was so good we thought we had found the holy grail, right up until I figured out the Bad.

Bad - Shortening the throttle cable caused the throttle pedal to change its location (elevation?) relative to the brake pedal. In stock form the throttle pedal is lower (Closer to floor/firewall) than the Brake pedal - and I quickly figured out why. In the modified form the throttle pedal is much closer to the same elevation as the brake pedal. The result is it is now very easy to accidentally also hit the throttle when applying the brakes, especially when hard braking like on the trail crawling.....

Basically, in stock form the relationship of brake pedal to throttle pedal helped avoid (prevented?) hitting the throttle when you brake with just the left side (big toe side) of your foot.

Again I thought maybe the answer was practice and muscle memory training to make sure when braking I moved my foot completely onto the brake pedal. After hours It got better, but I would still hit both occasionally, especially when switching back & forth quickly while in the rocks - which can get a little scary...

The modified throttle response is so much better that I really wanted to find a solution. The obvious answer is to somehow adjust the pedal elevations back to stock form.

The easiest solution was to raise the elevation of the brake pedal, in relation to the throttle, to match the stock relationship. The simplest way to accomplish this was to add thickness to the rubber brake pedal pad. I played around with adding layers of rubber to the brake pedal. The final solution that seems to have worked was stacking a second stock pedal pad on top of the first. I used Black Automotive RTV Silicone Adhesive/Sealant to glue them together. It seems to be a very strong bond and the silicone is thick enough I was able to fill the side seams - basically looks like one piece with no gaps or seams that would catch a shoe etc. I can now apply full pressure to the brake pedal with just my big toe and the rest of my foot does not engage the throttle. I compared the difference in elevation and it appears to match the stock gap (as compared to several stock LJ's I measured).

So if you managed to wade through all of this - TLDR - what do y'all think?
Is there a better solution than shortening throttle cable to fixing the throttle response issue?
Is there a better way to restore stock pedal alignment?
Are there any safety concerns I should have with my solution?
Any better way to change elevation of the brake pedal or "thicken" the brake pedal pad?

I am sure some of you will read all this and give me big DUH - I probably should have anticipated the pedal issue. Just hope to generate some discussion on possible solutions, and also warn others of the importance of pedal arrangement.

All input greatly appreciated!

 

[dbbd1]

What I have done, on my jeep and other vehicles, is to put a spacer, on the cable, between the cable end ferrule and the pedal. This leaves the pedal in the stock position but removes that 1" or so of slacking the cable. I still have a tad but not too much play now.

I made a spacer out of a nut. I drilled out the threads and smoothed it with a file. Then I cut a slit in it, big enough for the cable. Slip it on, crimp the slit closed and you're good to go.

 

[-T.]

Watching. I've always felt the pedal is a bit too touchy when in 4lo. It's almost like, when you switch to 4lo, you need the cable to switch to a different ratio on the throttle body as well, so that you can ease into that first bit of throttle better. Like changing gears on a bicycle. But maybe pulling some slack out will help as well. This is one of the benefits to being on a drive-by-wire system. You can change this stuff.

 

[Rick2004LJ]

What I have done, on my jeep and other vehicles, is to put a spacer, on the cable, between the cable end ferrule and the pedal. This leaves the pedal in the stock position but removes that 1" or so of slacking the cable. I still have a tad but not too much play now.

I made a spacer out of a nut. I drilled out the threads and smoothed it with a file. Then I cut a slit in it, big enough for the cable. Slip it on, crimp the slit closed and you're good to go.

This is basically what we did - but on the Jeep, because of the geometry of how the pedal is mounted, when you shorten the cable it moves the pedal "up" closer to the level of the brake pedal......

 

[Rick2004LJ]

Watching. I've always felt the pedal is a bit too touchy when in 4lo. It's almost like, when you switch to 4lo, you need the cable to switch to a different ratio on the throttle body as well, so that you can ease into that first bit of throttle better. Like changing gears on a bicycle. But maybe pulling some slack out will help as well. This is one of the benefits to being on a drive-by-wire system. You can change this stuff.

Just be aware - if you pull out some "slack" it moves the level of the throttle cable....

 

[mrblaine]

Kind of resurrecting an old thread - wanted to update what we have tried, warn about some mistakes, and get other ideas/opinions.
Old thread - https://wranglertjforum.com/threads/touchy-throttle-response.14314/

2004 Unlimited Auto trans - I had issues with throttle response. It seemed like there was slack/slop in the throttle linkage which made it difficult to smoothly apply power, especially when crawling etc. Per much advice on previous thread, I assumed it was just a function of getting used to it, training/muscle memory for the right foot. Put in 50+ hours on the trail, but it only got marginally better.

Mechanic suggested to replace the throttle linkage (even though existing looked fairly new and in good shape) which we did. No change. Mechanic (not a Jeep specialist) was a bit baffled by the amount of travel the throttle pedal has before starting to engage. He suggested we try shortening the cable a little bit and we tried it. Here were the results:

Good - MUCH better throttle response, much easier to maintain smooth power especially when bouncing around on the trails. Was so good we thought we had found the holy grail, right up until I figured out the Bad.

Bad - Shortening the throttle cable caused the throttle pedal to change its location (elevation?) relative to the brake pedal. In stock form the throttle pedal is lower (Closer to floor/firewall) than the Brake pedal - and I quickly figured out why. In the modified form the throttle pedal is much closer to the same elevation as the brake pedal. The result is it is now very easy to accidentally also hit the throttle when applying the brakes, especially when hard braking like on the trail crawling.....

Basically, in stock form the relationship of brake pedal to throttle pedal helped avoid (prevented?) hitting the throttle when you brake with just the left side (big toe side) of your foot.

Again I thought maybe the answer was practice and muscle memory training to make sure when braking I moved my foot completely onto the brake pedal. After hours It got better, but I would still hit both occasionally, especially when switching back & forth quickly while in the rocks - which can get a little scary...

The modified throttle response is so much better that I really wanted to find a solution. The obvious answer is to somehow adjust the pedal elevations back to stock form.

The easiest solution was to raise the elevation of the brake pedal, in relation to the throttle, to match the stock relationship. The simplest way to accomplish this was to add thickness to the rubber brake pedal pad. I played around with adding layers of rubber to the brake pedal. The final solution that seems to have worked was stacking a second stock pedal pad on top of the first. I used Black Automotive RTV Silicone Adhesive/Sealant to glue them together. It seems to be a very strong bond and the silicone is thick enough I was able to fill the side seams - basically looks like one piece with no gaps or seams that would catch a shoe etc. I can now apply full pressure to the brake pedal with just my big toe and the rest of my foot does not engage the throttle. I compared the difference in elevation and it appears to match the stock gap (as compared to several stock LJ's I measured).

So if you managed to wade through all of this - TLDR - what do y'all think?
Is there a better solution than shortening throttle cable to fixing the throttle response issue?
Is there a better way to restore stock pedal alignment?
Are there any safety concerns I should have with my solution?
Any better way to change elevation of the brake pedal or "thicken" the brake pedal pad?

I am sure some of you will read all this and give me big DUH - I probably should have anticipated the pedal issue. Just hope to generate some discussion on possible solutions, and also warn others of the importance of pedal arrangement.

All input greatly appreciated!

You should not be using one foot to drive offroad. Use the throttle foot to work the throttle and stabilize it by forcing it against the trans tunnel and then just lean in the side of it to gently apply throttle. The other foot is for the brake. Use it just for that.

 

[-T.]

You should not be using one foot to drive offroad. Use the throttle foot to work the throttle and stabilize it by forcing it against the trans tunnel and then just lean in the side of it to gently apply throttle. The other foot is for the brake. Use it just for that.

I'm not sure if this a 'should' or 'should not' issue, but I am generally 2 footing the Jeep on the trail as well. I find I can run a trail, especially the rough portions, much more smoothly by being modulating the brakes. Many times, I am holding the throttle in one position and using the brakes to control wheel speed, in the technical stuff.

Sent from my moto g(6) using Tapatalk

 

[CaliSteve]

You should not be using one foot to drive offroad. Use the throttle foot to work the throttle and stabilize it by forcing it against the trans tunnel and then just lean in the side of it to gently apply throttle. The other foot is for the brake. Use it just for that.

Am glad you mentioned the two foot approach, just did a difficult trail this week-end and was experiencing the lurching in 4lo while going down a steep pothole trail. I have definitely learned something today.

 

[mrblaine]

I'm not sure if this a 'should' or 'should not' issue, but I am generally 2 footing the Jeep on the trail as well. I find I can run a trail, especially the rough portions, much more smoothly by being modulating the brakes. Many times, I am holding the throttle in one position and using the brakes to control wheel speed, in the technical stuff.

Sent from my moto g(6) using Tapatalk

You should drive with both feet. You should not be using much brake to modulate speed. Learn how to give it just enough throttle to get it moving and then keep it there. It will help you learn how to keep the tires at the limit of adhesion when climbing tougher stuff.

 

[-T.]

Yeah, that's pretty much what I was saying. Slight throttle to keep the Jeep moving, but brakes to hold it back a bit here and there and control wheel speed. Bumping up onto steep ledges, I'll run the RPMs up a bit more to lean on the torque converter and then release the brakes to sort of pop the Jeep up. But then, we're not exactly talking golf swings here.

 

[mrblaine]

Yeah, that's pretty much what I was saying. Slight throttle to keep the Jeep moving, but brakes to hold it back a bit here and there and control wheel speed. Bumping up onto steep ledges, I'll run the RPMs up a bit more to lean on the torque converter and then release the brakes to sort of pop the Jeep up. But then, we're not exactly talking golf swings here.

That isn't what I am saying though. Use the throttle and if you need slower, less throttle.

 

[-T.]

Yes, I understand you. There is regulation at both pedals. And sometimes, some throttle, and some brake together, actually works quite well. For me. I'm not advocating for holding the Jeep at 2500 RPM and standing on the brakes all afternoon. That would be bad. I believe the point here is that, in most cases, and with an auto, 2 footing it generally works pretty good.

 

[mrblaine]

Yes, I understand you. There is regulation at both pedals. And sometimes, some throttle, and some brake together, actually works quite well. For me. I'm not advocating for holding the Jeep at 2500 RPM and standing on the brakes all afternoon. That would be bad. I believe the point here is that, in most cases, and with an auto, 2 footing it generally works pretty good.

Do as you wish. I am one of the smoothest automatic driver's you will ever run into and I don't do it that way.

 

[-T.]

LOL! Ok then!
Well, regardless of my less than perfect technique, I promise that I'll never 'run into you'. I'll fully lift my right foot off the throttle and further apply my brakes with my left before I do!