transmission diagnosis....I think I already know the answer

Hey guys, I broke the ring gear on my car a few weeks ago on launch. I replaced the ring and pinion and when I started the car on the jack stands, I only get reverse gear. No 1st, 2nd or 3rd. The car has a 904 with manual valve body. When I built the trans, I put in a new bolt in sprag. Is this what probably got damaged or am I looking at other areas of damage? Looking for some insight before I pull the trans. Money is tight.

since it's on jackstands.... do you feel it engaging in R? ...or are the wheels just moving in that direction. Guess I'm wondering if you think it would move if it were on the ground. thinking stripped plantetary perhaps.

Gonna hafta "go in " to fix the no 1-2-3 problem anyway.Inspect closely when disassembled.Could have failed without turning the race in the case.

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Front planetary is toast. And a very good change your over riding clutch went south a well. Good luck. That transmission need to come apart.

I feel it "hit" reverse and power the wheels. I think it would move on the ground but did not try it. I wasn't even considering the front planetary. The overrunning clutch everyone told me when I broke the rear would be damaged. Thanks for the input guys

they don't always get damaged. we've broken gear sets in the past, repaired them, and all was well.... of course this was in the "dark ages" before we knew better. I just tore down a trans last weekend with 904 internals that broke a drive shaft. All was A-ok. Hopefully some parts from a cheap core will get you back in action.

Rear band applies in reverse. It will also apply in low if the VB is LBA. If it is not LBA, it relies on the roller clutch to hold the drum in low. Still should run in 2 or 3 unless something else is broken. Regardless, it needs to come out and be closely inspected. No way should it be run.

Jack stands is the absolute worst place to test an automatic transmission's function.

If I can not get my car in any forward gear with a manual valve body what difference does it make whether it is sitting on the ground or not?

With the engine running, trans not in park, everything is going to rotate whether the thing is in gear or not. On jack stands, you will have to drag the brakes to get some load on it to get any idea of what it's doing.

No forward gears means the rear clutch isn't engaging, probably a broken Belleville or blown piston seals....air test will tell.

In Reverse the rear planetary is driven directly from the front clutch, even if the front planetary was missing you'd still have Reverse.