'65 A904 Diagnosis Problem

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dibbons

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Took the '65 Formula S Torqueflite to my transmission guy to perform a basic rebuild. Obviously, we found some smooth clutch plates.

However, he said he had to use needle nose pliers to straighten some clips inside the very heart of the transmission to remove some kind of cylindrical roller bearings. He said since he found them bent that way and had to straighten them out by hand with needle nose pliers. Then he said that it's doubtful a rebuild would last very long if he rebuilds it in in its current state. He also said these clips that hold these roller things are not serviceable and I may have to find another transmission. Doesn't leave me with many options. I am a little confused by it all, to tell you the truth.

Since all of this was explained to my in Spanish, I'm not sure what he's talking about. I never heard about a transmission having a fatal flaw like this and could not be repaired. It was shifting when I removed the transmission a couple of years ago (just started to notice a one or two second slip once in awhile).

The first photo shows the area I am referring to, way back at the end of the photo around the main shaft you can see a dozen or so little tabs. Those tabs I believe are what he was worried about. What is that back there anyway, the rear pump, over-running clutch? Heck, I don't know. Thank you.

904 exploded 1.JPG


904 exploded 2.JPG
 
If he doesn't know the sprag is replaceable, or what it's called, you need another transmission guy.
 
Retrieve your tranny ASAP before he screws anything else up like your valve body.
Those are rollers for the sprag not bearings for a roller bearing.
 
The replacement sprag is a bolt-in item. It is generally considered a good upgrade.
 
Thanks for the advice. Just one question now: there appear to be four bolts in the kit while I see maybe six dowels in the photo. So only need four bolts?
 
The forward clutches are supposed to be smooth. Your fluid looks like you would have minimum clutch wear.. If the ramps in the sprag weren't boogered up, I wouldn't have replaced it.
 
One clutch was completely smooth on 1/3 of one side, whatever that means.

Does this youtube guy know what he is doing?

 
he had to use needle nose pliers to straighten some clips inside the very heart of the transmission to remove some kind of cylindrical roller bearings. He said since he found them bent that way and had to straighten them out by hand with needle nose pliers.

Those accordion springs almost always need tweaking.
I have seen them worn paper thin on the pleats, and even crumbling. I think your guy has got that part right , but just doesn't know that they are sold separately.
If they are reusable, I also use a needle-nose to stretch them back out. If nothing else it makes me feel better.
 
Update: I ordered the sprag kit recommended in post #2. I can find no video on the internet covering the replacement on the 904 (727 only). According to the FSM, with the 904 the heads of six rivets must be:
1) center punched
2) drill rivet head with 3/8" bit (do not cut into transmission case)
3) chisel off the heads of the rivets
4) remove old piece
5) enlarge holes with 17/64" bit
6) clean up chips, install bolts/washers, torque to 100 inch-pounds (not ft-lbs)

If anyone knows of a video specific to this operation on the 904, please post a link. Thank you.
 
Like I mentioned earlier, all the tabs were bent before disassembly. The tech straightened them all back with needle nose pliers. Now we don't trust the strength/integrity of the tabs since they were bent and straightened. Metal fatigue?
 
when you say tabs; are you talking about the short metal stand-up pillars that anchor the accordion springs?
If yes, Boy, I have never seen those bent nor can I imagine how that happened.....
 
Those tabs only serve to hold the ends of the accordion springs; just a few ounces of pressure. The springs themselves are what fatigue and should be replaced many times.
 
when you say tabs; are you talking about the short metal stand-up pillars that anchor the accordion springs?

Yes, those tab things.

The replacement is covered in the 1965 factory service manual (page 21-100) and the parts are available in the aftermarket so there must be a good reason to replace these parts. I'm no transmission rebuilder, so can't comment on that from personal experience.
 
Maybe he bent them back down and didn't realize they were supposed to be straight up? Either way, find a new transmission shop, or do it yourself.
 
I don't consider myself a "transmission" guy, but have worked on and rebuilt many 904s and 727s. While at a dealership, worked on several just out of warranty. Mostly these were burned up, fried clutches with material clogging filter. For a reason unknown to me, the spraggs were bad in that the springs were completely collapsed, I'm assuming due to the heat. The rest of the spragg was OK, so we used a spragg "kit" consisting of springs and rollers only to repair. Your damage seems a little more severe. I recommend a new complete bolt in spragg and a more competent mechanic, or take it on yourself and we can help.
 
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