904 misbehavin'

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64ragtop

64ragtop

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Finally got the ragtop out and ran about 80 miles the other day. At 50 miles or so, the trans was balky at shifting into 3rd. I put it in neutral, blipped the throttle and went back to drive. The tranny went into 3rd just fine. For the rest of the ride, the 2nd - 3rd shift was a maybe, but the procedure I mentioned worked. I'm worried. Anyone have thoughts about this behavior and how to fix it? Thanks!

ATB

BC
 
Souds like the kickdown rod is not returning all of the way. Make sure the linkage is not binding and Try a spring on the slotted rod at the carburetor end to make sure it is returning all the way.
 
I think you must mean the spring shown as #13 in the drawing, running parallel to the slotted rod, #12. I've never known what function it has, much less how to calibrate or adjust it. haven't found reference to it in my FSMs either. Any help much appreciated.
 

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If your car is a 64 it wouldn't have the slot or the spring. Those are a safety feature added in later years.

They're designed to prevent the kickdown linkage from forcing the throttle open in the event that a stick or other debris got wedged in the linkage. Under normal operation, the spring keeps the pin on the carburetor linkage at the back of the slot.
 
The car is a '64 Dart GT, but was originally a slant six car. The P.O. told me that they jacked up the '64 and drove a '74 under it. So, it got disk brakes, 8 1/4" rear, 904 trans, 318 w/Thermoquad and it definitely got the spring and slotted rod. Would that spring being weak cause the problem I reported? Would it prevent the kickdown rod from returning, as the first response suggested? Thanks!!
P.S. 10-4 on your sig, 65!!
 

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It looks like in your picture that it should have the springs needed to return the rod unless there is some sort of binding. If it is having trouble returning all of the way forward, it will mess up your shift points. Also make sure the fluid level is ok if you havn't done so.
 
I guess too week of a spring coupled with a build-up of grease or other drag could cause the problem you've described.

But it's important that the spring be weak enough so that it is overcome by the throttle return spring. If you pull the kickdown linkage forward the throttle should stay closed. If the spring it too strong it will overcome the throttle return srping and open the throttle. That's what the safety feature was designed to prevent.

I guess as a test, you could put a really strong spring on it or even a peace of wire. In that case you would be at no more risk than if you were driving the early design without the slot. If the problem goes away then you can try to locate a spring with the proper strength.
 
This should be all the way, or most of the way forward in the idle position.
 

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............u totally have the wrong rod on top, looks 2 b a 2bbl rod..........source the correct part..the rod gets pushed by the carb stud.....kim......
 
With the throttle at idle and pulling forward on the rod, the rear end of the slot should touch the pin on the carb. In your picture it looks like it is adjusted completely opposite of that.
 
plypete said:
With the throttle at idle and pulling forward on the rod, the rear end of the slot should touch the pin on the carb. In your picture it looks like it is adjusted completely opposite of that.
Click to expand...

Yep
 
When Trailbeast and oldkimmer pointed out in the photo I posted the error in my kickdown rod setup it became blindingly obvious and I realized how the linkage really works.

The throttle cable PULLS on the carbs throttle linkage stud, which then PUSHES on the kickdown rod.

Or, at least it would had some fool adjusted it correctly in the first place!!!

Thanks for the guidance, folks

Kickdown linkage adjustment tomorrow!

ATB Merry Christmas to all, and to all a good night!

BC
 
How are the shift points for 1-2? If they are late too or excessively harsh check you kickdown linkage. If your problem is just in the 2-3 shift you may have a failed front band or leaking front servo. Another possibility is a sticking shift valve in the valve body.
 
65DartGTConv said:
The 2 bbl rod is indeed shorter than the 4 bbl rod. If you have a 2 bbl rod, you probably won't be able to adjust it far enough.

I went through this when converting my car to 4 bbl. I think this post will help you.

http://www.forabodiesonly.com/mopar/showthread.php?p=1969613512#post1969613512
Click to expand...

Thanks, 65. That's a good thread all the way through. The part your link goes to shows what I call the basic blacksmith technique - and it works quite well, as you proved.
I have the Edelbrock "linkage stretcher" part #8004, the NON blacksmith method. Looks like it will solve the problem.

(EDIT) A late Christmas present for me!! I found another length adjustment at the top of the rod that goes down from the upper to the lower bellcrank.
Cranked on it a bit and found that the back end of the slot at the end of the upper rod was very close to the carb throttle stud.
Minor adjustment of the slotted end piece of the upper rod, and now the upper rod starts to move to the rear at the same time as the throttle stud. (YAY!!)

I'd be test driving it now, but the voltage regulator bolts turned out to be stripped and I need some bigger bolts to ground the regulator case to the firewall.
Like the late lamented Roseanne Rosannadanna said "It's always something."

Old MOPARS - ya gotta love 'em

ATB

BC
 
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