Fresh 904....just stopped shifting.

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Duh-Star

Duh-Star

it runs....sorta...
Joined
Jul 1, 2017
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Location
Parker, Arizona
Good Day!
Thanks for all the help and tips in the past...your insight has made my 1972 Duster rebuild a ton of fun...

I recently installed a rebuilt 904 in my 360 powered Duster. I had Phil's Transmission in Mesa, Arizona do the install, a note on Phil's; Phil has rebuilt a number of trannies for me over the years....he is reliable and has a clean and very effective shop. I have never had a problem, ever, and Phil has always treated me well. I have never heard of a tranny leaving Phil's and having problems....that said....

My 904 had a -2 shift kit installed and rebuilt torque converter, I provided my engine build and cam card (mild cam with a dual plane intake, MSD, and unported "J" heads, full power steering and brakes and A/C) and also my anticipated rear end ratio at the end of my build. I told Phil to make it shift a bit stronger and up the stall speed just a bit. The tranny has been shifting great and today I was dialing in the kickdown (I wanted it to kickdown just after the secondaries open) and I had finally got it right. I tach'ed out second, let it shift up...opened the secondaries and it downshifted flawlessly and then tach'ed out second again with a hard shift and a little squeek from the rear tires.

Then that was it.....no power, no reverse, nothing. I have Park and everything else is Neutral.....coasted to a stop and my wife towed me home.

I checked the linkage, checked the kickdown, all good or so it seems...next weekend I will have to figure it out, until I can get the pan off or the thing out does anyone have any ideas or what to look for??

Note: I used Lucas 10418 Semi-Synthetic all makes transmission fluid. I had never tried it. I was talked into it by a friend who knows way more about drag racing than I do and he swore by the stuff. It is compatible with Dex-III although seemed a bit thin. However, it worked great...shifted strong and was at operational levels. The tranny has about 50 miles on it and functioned great...until now.

Thanks!
 
My guess is the that the manual valve went out of adjustment
But wait. First;Go to the last paragraph,lol
My second guess is that roller clutch failed.
And third is that the pump drive failed, but it's only third because the other third would be that both clutchpacks simultaneously failed,hardly likely
And fourth is that something inside the rearend failed, like axle splines or spiders.

I would jack up the back and verify the rear end is good, then pressure test the reverse circuit, after verifying the manual valve was not between gears.
With no pressure, the TC hub is probably torn off.
With pressure, you'll have to drop the pan, the VB, and do an air-pressure test. If it passes that and no junk in the pan, then the driveshaft will have to come down, for to test the roller clutch lock-up. If that fails then, well, it's the first thing that went in there, sooooo the trans will have to come down.

Unless someone else has a better thought.

Hang on, what are the chances that the TC retaining bolts all let go? That's a simple inspection, so that's the first go-to for sure.If those are all secure, the back to the top.
 
Last edited:
I will guess input shaft sheared. But a thorough investigation will be in order to find this problem. any noises with the engine running and in park or neutral?
 
omahamoparguy said:
I will guess input shaft sheared. But a thorough investigation will be in order to find this problem. any noises with the engine running and in park or neutral?
Click to expand...

No noise...not even a little whine or click. Rear end still works and the Park pawl still locks the tranny (an aside but I figure I would report that anyway). I will remove the dust cover and see if the TC bolts sheered after work today.
Please keep those suggestions coming...and thank you.
 
Duh-Star said:
Good Day!
I will have to figure it out, until I can get the pan off or the thing out does anyone have any ideas or what to look for??


Thanks!
Click to expand...

Yea, Phil's phone number.
You touch anything and you could void the warrantee.
 
AJ/FormS said:
Hang on, what are the chances that the TC retaining bolts all let go? That's a simple inspection, so that's the first go-to for sure.If those are all secure, the back to the top.
Click to expand...
Edit.....I'm wrong.....lol

Jeff
 
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