904- Hoping for an easy answer, because I'm lazy & crammed for time: A904 in 1975 Dart with only 274,000 miles, never opened except fluid & filter change. Daily driver. Recently began a slight shudder only when car is stopped at idle in Drive. No shudder in neutral, and seems ok when driving. Is there an easy (pan off) adjustment, or is it time for major surgery? Feels like a clutch is chattering or making contact when it shouldn't. I haven't been able to dive into the Service Manual yet for harder answers, so I'm just fishing for comments?

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"Louise", a 1976 Dart Custom project, (now sadly reverted to being just an "organ donor" to our other project Darts.)

Drop the pan... change the fluid & filter.
Inspect what you find in the pan for more "clues".

Use a good quality ATF upon refill and say a pray that the service process fixes the problem.
DD

I have found this diagram extremely useful in diagnosing what part of a 904 transmission has failed:



Ditto what the Good Doctor said. Chances are your clutches and/or bands are getting pretty thin. A band adjustment might be all you need, but 274,000 miles is quite a long service life for the clutches and bands.

If you need it, I have a fully rebuilt 1979 slant 904 ready to go under my workbench in my garage, WITH torque converter. I'll sell it for a fair price.

I had a '70 Valiant and it was shifting a bit weirdly, in my case soft, so I dropped the pan, changed the filter/fluid and it shifted great after that. There was about 1/8" of sludge in the bottom of the pan, maybe clogging up the works...

b

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https://tinyurl.com/yynpj4v2

Thanks guys. Last fluid / filter change I did adjust the bands IAW the 1975 Service Manual. Reed, the chart may help me troubleshoot just by putting it in each drive position and seeing what effect it has on the grumble noise. I'll keep you offer in mind- thanks. My dear wife drives the car like Mom's taxi, so another fluid/filter change probably would do it some good anyway.

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"Louise", a 1976 Dart Custom project, (now sadly reverted to being just an "organ donor" to our other project Darts.)

Does the trans make any metallic scraping noises when coming to a stop,or when the slipping is noticed. Next time it slips, try shifting into manual 1st and see if the slipping stops.

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V8?? We don't need no stink'n V8!!

Thanks. No other unusual noises. I checked the fluid level today-hot, idling in neutral- and needed only a pint, which I added. Then drove it on the freeway. No changes. (It drives and shifts beautifully.) I did determine that the rumble occurs, stopped at idle, in all drive positions including reverse, but never in Park or neutral. I'm thinking that before I go further into the direction of the transmission, I should first look over engine mounts etc. If I find anything, I'll post it here to satisfy peoples' curiosities. P

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"Louise", a 1976 Dart Custom project, (now sadly reverted to being just an "organ donor" to our other project Darts.)

Check the tightness of the inspection cover bolts, torque converter bolts, and check if the exhaust is hitting anything.

Park and neutral idle is slightly higher than in gear.

I get a slight noise when NOT in park and neutral....


Figured out it's my door panel.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes