Ok- got an engine and trans out of a 78-79 cordoba- 360 with 904. I have reverse and low 1 but low 1 is giving me reverse?? I have no working forward gears at this point. No idea unless the reverse drum is out?? Hopefully a cheap fix. It has all new fluid and filter-checked level in neutral. Neutral safety switch still doesnt work, but I really dont think this has anything to do with it. I have a spare transmission, but it hasnt run in over 15 years, so doubt it will work. Would hate to put that one in and not have it work either. Any ideas on the one thats in the car? Could this be low pressure from kinked line or stuck check ball?
904 trans has reverse in r and reverse in Low 1???
- Thread starter john27pa
- Start date
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fishy68
Tyr Fryr's Inc.
Sounds like a valve body malfunction cause it should never have reverse in low 1. To do that the front clutch pack has to be energized and when you pull the shifter in low 1 the valve body should never energize the front clutch. How did it look when you had the pan down? Was there much mud in the pan? Any metal shavings? Any rust?
Nothing out of the ordinary. Magnet-Ive seen worse. Im thinking maybe pieces from the old filter or a check ball sticking. Hopefully just a checkball and sitting overnight may loosen it up. Maybe a somewhat kinked fluif cooler line? Other than that??
fishy68
Tyr Fryr's Inc.
Kinked cooler line won't cause your problem. It has to be a problem with what the valve body is telling the trans. to do. Kinda like a computer when it gets confused and does things it's not supposed to do. The valve body is no different. It's just a mechanical form of a computer. If it doesn't loosen on it's own, which I doubt it does, you'll have to drop the valve body and very carefully take it apart and clean it good. All it takes is one little piece of debris to cause a valve or check ball to stick. While you have it apart I'd highly suggest doing an air pressure test. It's real simple to do and only requires a small air compressor set at approx. 30 psi.
Thanks-maybe Thursday when I have the day off, I will go and take out the valvebody. I heard its about 10 bolts and drops right out. Im just afraid of a spring flying into no mans land-never to be found again. lol
Lonewolf3165
Living the Dream!
The only spring you have when removing the valve body is the fairly large accumulator spring. And even if you lose that it's no big deal since shift kits eliminate that spring anyway. While you have it down check for any broken bands or anchors, levers etc. Sprag bits etc. It's quite possible something came apart & pieces of it have gotten into other parts & are wreaking havoc.
Pulled valvebody today- metal shavings are on it. Might be saveable for a short time, may not be?? Im going to be on the search for another 904 transmission now. I heard these are really easy to rebuild-is this true? Any "special" tools needed? Anyone have a good cheap one for sale around NW to SW PA? I can go as far as State College or so for the right price and around Ohio state line. The engine and trans I have are out of a 78-79 Cordoba with 360. I see that those years have a lockup torque converter. Do I have to put another lock up unit? I dont know much about transmissions.
green1
Well-Known Member
Ever checked the linkage?
Interestingly, I was doing donuts in a parking lot when I was about 15, and from about 10 MPH, slammed it in L1, and went backwards. Freaked me out. I put it in R verified it went backwards, then slowly put it back down in L1, and it was fine. Never happened again, and car ran for another year until I hit a tree. I wasn't the most carefull driver in my younger years. My mom put that same car in P going about 15 MPH. I thought sure she killed it, but it didn't.
Dont think the linkage is binding. I actually have all new linkage bushings in it. I didnt think the kinkage could bind or twist in a way where it goes back around to reverse. I pulled the valvebody out yesterday. Shavings are all over. Maybe some shavings are stuck in the valvebody-I think this because when I changed the filter-the old filter wasnt all there-looks like rats had a field day lol. So now Im looking for another 904 or maybe swap to a 727. I like the 904 for the gas mileage but may be able to get a 727 for $200. Just need to find out what length driveshaft I need.
Lonewolf3165
Living the Dream!
Linkage won't do it.
You can use a non lock-up trans in place of a lock-up. You must use the appropriate torque converter with it.
Yes, the TF727 & 904s are among the easiest trans to rebuild. Aside from a good basic set of tools you will need a set of snap ring pliers, a clutch drum spring compressor(a local trans shop will compress the piston for you & replace the seals for a small amount so you need not buy 1), a big C-clamp for the servos & you can improvise a pump puller for a couple of bolts & a length of chain. Have a manual by your side.
You can use a non lock-up trans in place of a lock-up. You must use the appropriate torque converter with it.
Yes, the TF727 & 904s are among the easiest trans to rebuild. Aside from a good basic set of tools you will need a set of snap ring pliers, a clutch drum spring compressor(a local trans shop will compress the piston for you & replace the seals for a small amount so you need not buy 1), a big C-clamp for the servos & you can improvise a pump puller for a couple of bolts & a length of chain. Have a manual by your side.
fishy68
Tyr Fryr's Inc.
Sorry I didn't get to answer back any sooner John. Had to go in for back surgery. Looks like Lonewolf got your question answered though. If you are going to rebuild it the only tools I'd add to the list he gave is a feeler gauge to check clutch pack clearance and a dial indicator to check the end play. Like he said get a manual. ATSG sells manuals that are basically copies of the original factory service manual so you can't go wrong there. You can find them on Amazon for about $15. Keep it a 904 if you can. The 727 is a fantastic trans. but overkill for most needs and sucks more power and gas mileage than a 904. When you get the old trans. out flush the trans. cooler out real good. Crap collects in them and I bet since you've had 2 bad transmissions now it's full of garbage. Good luck
Lonewolf3165
Living the Dream!
Yes, all very good advice here. :thumblef:
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