74 Duster, 360/904/8 ¼” 3.23 SG
My transmission in my 74 Duster decided to stop shifting into second gear so I found a junk yard A999 from an 88 Dodge truck to keep me going till I get a chance to rebuild the 904 this winter. I purchased the TCI balanced flex plate since the Junk Yard transmission had a neutral balanced torque convertor.
The transmission shifts well both up and down except for a clunk noise on the 1/2 shift. It doesn’t clunk under light acceleration but even under regular acceleration from a stop light (like you would do with a cop behind you) the clunk is pretty bad. As the transmission warms up, it gets better but doesn’t go away. In the research I did on the forum prior to posting this, I saw it mentioned that it is likely too much line pressure causing this so I loosened off the kick down (cable type) to the point that it will no longer kick down to second when flooring it at 40 mph but still shifts good. I can now pull the cable about a ¼” further by hand than it gets pulled by the carb linkage at WOT. This helped marginally but the clunk is still there. There is also a slight whining sound in only 1st gear that I have never heard from an automatic transmission. This whine seems to all but go away at full normal operating temperature.
A couple things I should say, is that when I was cleaning up the transmission for installation I removed a heavy weight bolted to the back of the tail shaft because I could not see any use for it and found it to be useless added weight (was I wrong?). Also, this transmission does not have any wiring or control circuit yet hooked to the solenoid at the rear left corner of the trans pan which I believe actuates the lock up torque convertor. Also, there is a little more backlash in the rear end than there should be but it never clunked with the old 904.
I did drive it a little this weekend, and when accelerating down an off ramp, I floored it, kicking down into 1st gear and shifting up through all the gears super smooth and strong. Not sure why it didn’t clunk this time.
This weekend I plan to drop the oil, change the filter and fluid again, check the band adjustment (however I don’t think there is any problem there since it shifts so well otherwise) in hopes of correcting this problem. What else should I look for? What else could cause this?
Cley
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