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snoopy2x

Substitute For OEM Hanging Gas Pedal in 1967 V6 CJ

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Like some others who have V6 CJs with the hanging (suspended) type accelerator pedal, I've found my '67 CJ5 to be somewhat uncomfortable to drive over long, and even not-so-long distances due to the awkward placement and size of the original stock gas pedal. It's no problem for me to reach the gas pedal with the front part of my foot when my heel is on the floor, as I wear a size 13 shoe. Even so, I've found that the muscles in the front of my shin frequently begin to ache from having to constantly hold my foot up at the angle necessary to depress the gas pedal.

It occurred to me that it might be possible to find a longer hanging-type gas pedal from a different vehicle which would be an improvement over the original jeep pedal. If so, this could allow the pedal to be depressed from a point closer to the floor, which could in turn allow the side or bottom of my right foot to rest against the transmission tunnel or the floor as I'm driving.

The stock CJ hanging gas pedal is rather short (4-5/8" long), and the roll pin pivot that attaches it to the mounting fork is directly in the middle of the pedal - meaning that only about 2-5/16" of the pedal's overall length extends downward from the pivot toward the floor. The pedal has a rubber cover molded over a fairly substantial steel backing plate. A torsion spring around the pivot pin presses against the top of the backing plate, pushing it towards the drivers' seat.

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I didn't think it would be a good idea to consider a plastic gas pedal as a possible substitute, considering the pressure of the torsion spring against the back. I started looking around online trying to find longer hanging-type pedals from other vehicles that were built similarly to the original jeep pedal, with a steel backing plate and rubber cover.

It didn't take long to figure out that there were really only a few potential substitute pedals that looked like they might actually work. Both Ford and GM produced a few different hanging pedals of this general type during the late 1960's - early '70s, and together these made up the possible contenders I was able to identify.

Out of this group, the most probable candidates appeared to me to be the two Ford gas pedals that were used in the 1967-72 F-100 truck (which were also used in the '64-'68 Mustang) and the 1966-77 Bronco (also used in several full-sized Ford cars). Another plus for the Ford pedals was that they both looked somewhat more like the CJ's original gas pedal than GM's hanging pedals did.

To test this, I picked up inexpensive examples of each of these two Ford pedals on eBay. They are shown below next to the stock jeep pedal. I ran a metal rod through the pivot / mounting holes of each pedal to make it easier to see how they compare in terms of their relative angles and lengths, especially their lengths below the pivot.

The stock jeep pedal at left has an overall length of 4-5/8", the F-100 pedal at center is 5-1/4" long, and the Bronco pedal on the right is about 6-3/8" long:

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I temporarily installed each of the two Ford pedals on the original mounting fork, tightening the fork on the control rod so I could sit in the drivers seat and try each one out.

There was some improvement using the F-100 pedal, as it's about 3/4" longer than the original pedal below the pivot. This places the bottom of the F-100 pedal 3/4" closer to the floor than the stock jeep pedal, making it at least a little easier to reach. However, the sloped angle of this particular pedal was a little too much for it to fit well next to the adjacent transmission tunnel when fully depressed. Another issue with using the F-100 pedal was that the narrow tab spacing on its mounting bracket didn't align well with the jeep's wider pivot fork (though it still could've been made to work).

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The Bronco pedal, with some minor modifications, turned out to be a very good fit for the CJ. Once installed, this pedal proved to have a good angle, width, and length for my foot to be able to relax a bit while depressing it. The bottom portion of the Bronco pedal, measured from the pivot to its lower end, is about 1-3/4" longer than that of the original pedal - so it's that much closer to the floor than the stock pedal, and that much easier to reach. Even with this additional length, due to its sloping angle, it still fits nicely down into the area next to the transmission tunnel when fully depressed.

In order to allow the mounting holes in the pedal to line up with those in the pivot fork, I modified the Bronco pedal slightly by cutting away two small areas on the rear of the rubber cover, then used a Dremel to slightly grind down the turned-up metal edges a bit in the areas where the rubber backing was removed.

The mounting hole tabs at the ends of the Bronco pedal's mounting bracket turned out to have almost exactly the right spacing to fit inside the jeep's pivot fork. These two tabs had to be compressed toward each other only very slightly, about 1/32", in order to get them to fit inside the tongs of the fork.

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Using a bench grinder to grind about 1/16" off the faces of the pivot fork closest to the pedal allowed it to rotate slightly on the pivot, like the stock setup was designed to.

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I used a 1-29/32" long AN23-30A Clevis Bolt with a thin 10-32 nylon-insert lock nut as the pivot in place of a roll pin, and assembled everything using a little grease between the moving parts. The end of the bolt was then ground down to the surface of the nylon insert, and the assembly was painted.

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With these minor modifications, the Bronco pedal works great on the CJ. Speaking for myself, at least, it created a significant improvement in the jeep's overall driving comfort as compared to the stock gas pedal - and IMHO, it looks good at the same time.

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Pedal depressed about halfway (note that most of my foot is resting on the floor):

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Pedal "floored", fully depressed:

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As a note of interest, this gas pedal is installed upside down from the way it was mounted by Ford on the Bronco. A buddy with a '76 Bronco told me that the mounting bracket on his gas pedal is closer to the bottom, rather than the top - so evidently the Broncos had a longer / lower accelerator control rod than the early CJs did.

In case anyone else wants to try this out, the Bronco gas pedal is Ford part number C5AZ-9735 D. When I was looking, there were many of these for sale on eBay, both used and NOS, and reproductions are available as well (though I'm not sure if or how well the repro pedals would work, as the one I used was a genuine Ford part).

Hope this is helpful to some others out there with a stock hanging gas pedal and a sore right shin!
 
La

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Snoopy2x...This is very innovative, thanks much for the detailed photos and description of how you chose the right pedal!  While the new pedal looks "made to fit", it's actually light years ahead of Kaiser/Jeep Corporation!  You have eliminated the close proximity of the pedal to the brake pedal, which was always a safety liability.  You clear the brake pedal more and being closer to the tunnel with your foot is actually a four-wheeler's coup:  You can rest the right side of your foot against the tunnel in rocky terrain to stabilize the throttle.  I taught Tread Lightly four-wheeling clinics with Bill Burke of 4-Wheeling America.  We pitched the idea of foot/throttle stabilizing...

Note:  The only time the OE pedal was at any advantage was off-roading under very trying circumstances with the need to work the brakes, gas pedal and clutch at the same time.  Actually, I'd still very much prefer your layout and pedal choice, even under those conditions!  Make sure the pedal does not hang up on the tunnel or floor matting.

The Bronco pedal seems the easiest to modify with the least amount of changes to the OEM cast bracket.  The only thing I would consider doing is finding a long shanked pin for the pivot bolt.  Grade 5 or better with a threaded end to accept a toplock or nylock nut.  I prefer self-locking toplock steel nuts available in Grade 5 and Grade 8.  John Deere and everyone else uses them.  They're readily available from hardware and automotive sources. Here are a variety of bolt/stud examples from the race car industry, stainless steel is nice although a well-equipped hardware store might have an acceptable substitute at a fraction of the cost:  https://www.fastfasteners.com/specificboltkits.htm.  

The aim would be a smooth shank that has no threads rubbing against the pivot bracket or pedal flanges.  The primary wear points are the pedal flange holes.  This would be lessened if screw threads were not rubbing on the flange edges.  Use of bushing sleeves in these pedal flanges might be overkill, and besides, there's no room for bushings.  These steel flanges will likely last another fifty years...

Thanks for sharing...Nice work, I like it!

Moses

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I believe I found a pin of the general type you described that will work....it's called a AN23-30A Clevis Bolt , and is actually an aircraft part.

17.Clevisbolt_zpsp9qfe77h.jpg

From the description:

Clevis bolts have a slotted brazier type head. They are special-purpose bolts for use where a large shearing stress occurs (never in tension). Manufactured and cadmium plated in same manner as AN3 - AN8 aircraft bolts. Minimum tensile strength 125,000 PSI.  

Yeah....that oughta' do it!

That site (click on the part name) has them for under $4 shipped.   I'll pick one up, and find a 10-32 locknut (the thin type to minimize any interference with the floor mat) to secure it. 

Thank you for compliment, as well as the great advice, Moses!

Maury

 

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snoopy2x...I looked at the catalog bolt...Nice descriptive, you want this kind of tensile as shearing strength, there's not an elongation issue.  This is fancy, too, in that you have the option of a drilled bolt to accept a castellated nut and cotter pin.  

If you use this approach, you'll need a flat washer under the nut, then the castellated nut and a common cotter pin.  (You'd have to aim the nut away from the tunnel/floor mat.)...Otherwise, an undrilled bolt would accept a nylock or toplock self-locking nut; the thin one you describe would work fine as long as it's Grade 5 or 8.  This nut should also have a flat washer under it.  

A stainless washer would work fine in either case, available at any hardware supply, Lowe's, etc.  Stainless is high enough tensile and offers a somewhat anti-friction surface.

Moses

 

 

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As it turned out, that particular website only had the undrilled type for the size and "grip length" bolt I needed....which is probably best anyway, given that it would be preferable to use a thin nut from a floor mat clearance standpoint (unless of course I were to flip it over so the nut is on the left, which I'd rather not). 

In the event that I can't find a thin flex-top metal locknut (without having to get it from somewhere like McMaster-Carr and pay over $15 for it including shipping), I may have to go with a thin Grade 5 or 8 nylon-insert type locknut.  If so, would you suggest using threadlocker on it to help ensure that it doesn't come unscrewed over time?

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snoopy2x...My suggestion about the use of a stainless steel washer, thin if necessary, will help minimize risk of the nut backing off.  Do I understand from your photos that the bolt tightens directly against the cast block?  The pedal flanges and spring are inboard of the block's arms?  Was the original bolt firmly attached and unable to rotate? 

Moses

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Moses, in the original setup, a (very) tight roll pin turned with the pedal, and the cast pivot fork rotated around that pin inside the pedal. 

In current setup, the holes in the Ford pedal's mounting bracket - which rides inside, rather than outside the fork - are slightly larger in diameter than the holes in the fork.  The holes in the fork are just large enough for the #10 bolt to pass through them.

You're correct in your interpretation of the photos.  I currently have the bolt tightened enough against the outside of the cast fork that the bolt turns with it, and the pedal bracket and spring rotate around the bolt inside the fork.

Does that adequately answer your question?  It's sometimes challenging to paint a word picture that clearly explains how even a simple a mechanical assembly works!

Maury

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Okay, snoopy2x...Now we can reverse engineer the aims of the pedal designer(s).  To prevent wear at the pedal flanges, the roll pin was firmly secured at the pedal flanges.  The spring roll pin, being spring steel and hard material, was in this case considered the consumable wear surface.  The cast pivot, if common gray iron, would be a relatively light 40-45,000 tensile.  I'd be surprised if this piece is a forging or higher tensile.  

Footnote:  If worn out, the cast pivot fork could be repaired and improved using nickel content iron filler rod like Weld Mold Company's 750. 

The wear on the OE pedal arrangement would be limited to the roll pin and the bore of the cast pivot.  The load is distributed over the casting's bore, and wear would be slow.  Likely the part was intended to outlast the Jeep, especially since the pedal movement is not a rotation as much as a rocking back and forth.  On that note, was there wear in the casting's pivot bore?  On the roll pin surface?

I'm guessing that you did not return to the spring roll pin because the Ford Bronco pedal flange holes are too big for a secure/tight roll pin fit?  If so, the goal now is to minimize wear at the pedal flange holes, which are subject to wear from riding (with clearance) on the new through bolt.  

Since you want to minimize wear at the pedal flange holes, I would allow the bolt to "float" in the cast pivot fork bore and also at the pedal holes.  To do so, use a stainless steel washer (can be thin if necessary) under the head of the bolt and also under the nut.  Tighten the self-locking toplock or nylock nut to seat parts, then back the nut off just enough to let the bolt rotate without drag.  There should be little if any end pressure (other than pedal side thrust), but I'd check the nut periodically for tightness until you're confident it's not loosening.  Safeguarding with Loctite 242 would be practical.

By allowing the bolt to float, it will rotate in the pivot casting bore and also in the flange holes.  This will distribute the friction load and even out any wear.  You can check for pedal flange hole wear by rocking the pedal sideways and checking for play.  I'm curious how long it takes to show any wear...Given the availability of this common Bronco replacement pedal, wearing out should not present an issue.

Moses 

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Moses,

The 1-29/32" long AN23-30A Clevis Bolt showed up today, though I still I don't have the 10-32 lock nut in hand yet.  I re-lubed the assembly and test-fit the bolt, and I'm happy to say that it fits perfectly.  The unthreaded shank portion of the Clevis bolt (also referred to as the "grip length") extends from one outside face of the fork nearly all the way to the opposite outside face, leaving only a couple of millimeters or so of the threaded portion behind the opposite face's outer surface. 

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During the test-fitting I learned something interesting.  Between the pressure of the torsion spring and the relatively tight clearance between the bolt and the holes in the fork it passes through, the bolt rotates entirely in sync with the fork.  This is the case even though there's not a nut on it yet. 

The more I think about it, this may actually be for the best.  Since the bolt rotates along with the cast fork rather than turning inside it, the rocking of the pedal over time will have less tendency to enlarge the holes in the fork.  Repairing or replacing that original part, if it were to wear significantly, might not be so easy. 

By contrast, as you correctly pointed out, original Bronco pedals and/or reproductions are plentiful and relatively cheap.  If the holes in the pedal bracket were eventually to become too enlarged due to wear from rocking on the bolt (which is probably unlikely in the first place, given that I only drive the jeep a few thousand miles a year at most), it wouldn't be difficult or costly to find another pedal to replace it.  

I'm thinking that given the above, the pedal rocking on the bolt, and the bolt rotating with the pivot fork, might actually be preferable.  Would you agree?

Maury

 

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snoopy2x...Sounds like you're in good shape here...The shank area (not the thread portion) of the new clevis bolt is ideal length.  This relationship of parts is optimal  and should minimize wear.  Better to make the pedal "consumable" than the cast pivot fork, as the OE piece is likely becoming rare.

As for whether to tighten the self-locking nut securely or without pressure on the bolt, if you're confident the bolt will always pivot in sync with the cast pivot fork, you might as well secure the nut.  The wear points will be the pedal flange holes.

Moses

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Thanks, Moses!  

Here's the painted finished product with a Gr. 5 thin nylon-insert 10-32 lock nut, and the threaded portion of the Clevis bolt ground down to its surface.  To further discourage it from unscrewing over time, I also used red ("permanent") threadlocker when I installed the nut:

19.IMAG0073_zpszwzbocij.jpg

  

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Snoopy2x...The threads penetrate through the nylon, right?  Hard to see from this angle.  That should do it, minimal stick-out of the nut and bolt.

As a footnote, use prudence and go slowly when removing threads with a grinder.  The bolt's tensile is impacted if overheated.  This clevis should be through-hardened, there's less likelihood of altering the tensile strength from grinding.  Nice wrap-up of the project with this upgrade of hardware, let's see how the pedal flange holes hold up.  Looks terrific!

Moses

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Hi Moses, yes, the threads do penetrate through the nylon insert.  I tightened the nut, then ground the threaded end of the Clevis bolt down slowly until I got to the surface of the nylon. 

I'm pleased to report that there is no contact between the thin lock nut and the floor mat (though it's close).  

Thank you again for all your help and advice on this project, Moses!  I'm happy with the way it worked out too.

Maury

 

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