UPDATE: More DJ-3A carb info here:
On Thursday evening I spent time moving parts from Patterson’s stock, but tired, DJ-3A engine to Rusty’s rebuilt M-38 engine so I could install it in Patterson. One item that caught my attention was Patterson’s DJ gas pedal linkage versus Rusty’s. Patterson’s appeared stock, while Rusty’s had a modified pivot point, probably the result of using the M-38 block. I decided to keep Patterson’s as it was and recreate the part for Rusty’s engine.
DJ-3A gas pedal Linkage: The linkage goes through the firewall to a pivot point on the driver’s side. When the gas pedal is depressed, a rod pushes an angle piece around a pivot, forcing a second rod upwards to a YF 2392S carb, causing the gas flow to increase.
Patterson’s real pivot piece (and it seems I misspelled carburetor in my pic).
This shows the piece after removing the parts. The pivot bolt is solid on the end with a hole for a cotter pin.
Example of what I removed from Rusty (bottom) and the bolt I will use to make a new one (top with new threads extended up it so I can add a bolt). The biggest problem with the custom piece at bottom is that it had no cotter pin. It was only held on by a bolt, which could have easily have come unscrewed as the gas pedal pivot piece moved back and forth.
Here the new piece has been drilled at the end.
One addition I made to this pivot was to scallop the end so I could use a wrench to screw the piece into place.
I’ve added some additional washers to give it a snug, but not tight fit. The pivot piece could still easily pivot, but there’s no danger of it coming off due to the cotter pin.
Another angle:
The final piece was to install a spring. Normally, as best as I can tell, the spring should reach down to plug with a hole on the block. But, the plug on Rusty’s block was solid. So, I pinned the spring to a different location. We’ll see how this works. You might also notice that Patterson’s block came with an electronic oil sensor (lower right). I moved it to Rusty’s block.
This photo I borrow from Charles Tate (off this thread). It shows the upper part of the gas pedal linkage at the point it connects with the carburetor. 
The linkage appears ready now.
Compare the above linkage to a few other vehicles:
- F-head linkage has a few parts in common: https://www.willysjeepparts.com/gallery2/d/16258-3/Fuel%20Accelerator.jpg
- The CJ-3A system mounts to the rear of the engine: http://www.cj3apage.com/3Ayabbfiles26/Attachments/IMG_20141014_134338_opt.jpg
- CJ-2A system: https://www.thecj2apage.com/forums/1946-willys-carb-linkage-and-springs_topic25666.html
A couple other notes: I was surprised to find an electronic coolant temp sensor on Patterson’s engine. I was even more surprised to see it has an F stamp.
I was also surprised at the condition of Patterson’s engine mounts. They appear partly melted. In contrast, despite the abuse Rusty endured, it’s engine mounts were in good shape.
I replaced them with new ones. Anyone else have this happen?
I just have a suggestion. They make, I think it’s graphite impregnated bronze/brass bushings. What ever it is impregnated with, I forget, they are self lubricating. Might reduce wear on your gp linkage. I did the same thing to the clutch linkage on my Wrangler. Love reading abt your progress on your DJ’s, keep us updated. Thanks.
Take good care of your gas pedals and attached linkage that goes to that pivot. The ones that fit DJ’s are not reproduced.
Dave, just a guess that the coolant temp sensor may be from a flathead v-8 ford.I think my flathead ford has two of them.I will try and look when I get a chance.
Glib: I can’t say I’m impressed by the system. There is visible wear on the linkage end from the gas pedal, in the same way that the linkage on the clutch rod eats into the rod. Simple, but easily worn. This will work for the Alaska trip, but I’ll be rethinking this on Patterson. Rusty will get the stock treatment.
Our local farm stores have a good selection of those bushings.
Charles: Good to know. I couldn’t find them documented, except by you, let alone for sale. I was surprised to see the changes between the CJ-3As and DJ-3As.
Thanks Doug!
Looking good Dave, and great thinking!
Quote by Dave “I was surprised to see the changes between the CJ-3As and DJ-3As”
Me too. For a jeep that was supposedly a cheaply made back in the day two wheel drive vehicle by utilizing mostly left over 4 wheel drive parts there was enough DJ specific parts used here and there that are hard or almost impossible to track down when a person needs them that are not reproduced.
That being said only recently did I learn quite by accident that both CJ3A’s and DJ3A’s shared the same engine prefix of 3J!!!
Carbs, intake manifolds, linkages…..were only some of the things that were different bolted to that motor but the CJ3A database certainly verifies that both of them used the same 3J prefix!.
Charles, Barry West here (apprentice on CJ’s and DJ’s. A few questions on those differences mentioned above. Because of the different carbs, intake manifolds and exhaust manifolds was there a difference in HP between the two? If so, which one was less or more?
Hi Barry. As a DJ3A Enthusiast I have to limit my response to that carburetor only.
Quote from Bruce Agan (jeepsurreygala.com) and premier expert on DJ3A Dispatchers September 20, 2011 07:42 PM
“the dj has always used the YF carb. 1955-56 parts lists show both the YF 2392 & YF 738S & 738SA carbs used on the early DJs. the YF 738 carb was the original carb used on the 4-63, VJ-2, VJ-3 (Jeepster”
Quote from OLDTIME from Deriks CJ3B bulletin board
“The specifications for the 2392 S are not identical to the more commonly found Jeep YF carburetors.
That implies differences such as the main metering jets, the metering rods etc. ”
Those specifications can be seen on Carter form #’s 5170 and 5170d
The difference between yf2392s and 2392sa was likely going from a air bypass check ball an air bypass check needle.
As said Barry I know absolutely nothing about the earlier CJ3A carbureator per sey. What I ‘think’ is that the YF Series carburetor used on the DJ3A dispatcher had a larger throat bore.
IF SO, then we can refer back to this comment from KEN (OLDTIME)
“Larger diameter throat bore = decrease air velocity = increase of the air % to fuel % = lean fuel mix =
better operation at high altitude or burnt valves at designated altitude”
If all of the above is true then it might also be true that better operation doesn’t necessarily equate to more actual horsepower???
More information and my actual rebuilding of a yf2392s carburetor here along with some of the research quoted
http://z4.invisionfree.com/CJ3B_Bulletin_Board/index.php?showtopic=5753
Dave,my 1953 Ford truck v8 has two temp sensors.they have machine screws to attatch the wires,not stud and nut type like yours.I was not able to see an f mark.Yours still could be from an earlier Ford engine,others may be able to comment as I am certainly not an older Ford engine expert!