Lost Reverse in 904. Please help!

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Walker434

Walker434

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Hello, I have a 71 Dodge Dart with a 360/904. I know nothing about whats been done to the transmission as it was in the car when I bought it. A few months ago I swapped out the old tired 318 for a 360 magnum. A lot more horsepower and torque so I knew eventually I would have to beef up the 904 but I was hoping to get another year out of it.

Anyway, this weekend I was out for a drive and found out I had lost reverse. Reverse just acts like it's in Neutral but in Neutral the car acts like it wants to move forward. I still have all the forward gears. The trans fluid level is correct and the fluid looks good and does not smell burnt.

The linkage appears to be correct.. maybe just out of adjustment? Something else wrong? I really hope this is nothing too serious I would like to get a few more miles out of this transmission while I save to rebuild it. Thanks in advance for any help.
 
Pull the pan and hopfully you will find the rear servo cocked in the bore and missing the lever for the rear band.
You also may find the strut laying in the pan when it comes off.

I'd be tickled to find either one of these, because they can both be easily fixed with the pan off.
If the rear band broke the trans has to come out and be completely diassembled to replace it.

Pull the pan and have a look, as that will tell everything you need to know.
 
You wrote it pulls forward in neutral. Smell the fluid. If it smells burnt you most likely burnt the front clutch which is used in reverse and 3rd. I hope it's just the reverse servo cocked in the bore like TrailBest suggested.
 
Since you say the fluid does not smell burned and you have all forward gears (I assume you verified that you do in fact have 3rd gear, not just 1st and 2nd) that indicates that both forward clutches should be ok. As Trailbeast said it's possible it's a rear servo problem. It's also possible the trans. has never been serviced and the rear band is just way out of adjustment. When you drop the pan look the rear servo over good and if everything looks like it's in place check the band adjustment. I first grab the servo lever by hand and see how much free play there is in it. Shouldn't be a whole lot. If so the band needs adjusted. The manual says to torque it to 72 inch lbs then back off 3-1/2 turns. If you don't have an inch lb torque wrench there's an alternate way you can do it. Back the adjuster locknut way off and tighten the band up snug so you can't even begin to turn the rear drum by hand then start slowly backing off the adjuster. At a point the drum will free up so you can spin it by hand. At the point where you feel there's no drag at all from the band back it off another 1/4-1/2 turn and tighten the locknut making sure the adjuster didn't spin. Good luck
 
Could be 2 problems. Failed L/R band/strut AND dragging hi-clutch(called front clutch by Ma Mopar).Could be other things too.
But like trailbeast says; drop the pan. Theres really no other choice for now.
 
Thanks for the replies everyone. It will be a little while before I can pull the pan since I don't have a shop. I use my buddies shop about 45 miles away. One thing I forgot to mention is that it will not roll backward in reverse or neutral with the engine running. Shut engine off it rolls back just fine.
 
Walker434 said:
Thanks for the replies everyone. It will be a little while before I can pull the pan since I don't have a shop. I use my buddies shop about 45 miles away. One thing I forgot to mention is that it will not roll backward in reverse or neutral with the engine running. Shut engine off it rolls back just fine.
Click to expand...

Just remembered one case I saw where the rear clutch pack was burned up so bad it welded itself together and it caused the same symptoms. Only thing is the fluid was burned real bad so that was a clear indicator that the trans was burned up. How many miles does this trans have on it?
 
Fishy, I wish I knew how many miles were on it. This trans was in the car when I bought it and the seller didn't know much about it. I'll post back here when I get a chance to pull the pan. Thanks FABO.
 
Okay just an update, I still haven't had time to pull the pan but I had to drive the Dart this weekend because my daily driver broke down. I have now lost 3rd gear as well so I would say my transmission is toast.

Time to start saving pennies to beef this thing up I guess. Oh well.
 
Yeah that's what I figured. I had planned on having to rebuild this thing after the motor swap I was just hoping it would survive a bit longer. Thanks for the help everyone.
 
I had a 68 Dart a number of years ago that didn't have reverse. Pulled the plan and the strut was laying in it. The bracket that is welded onto the rear band had broken off. I pulled the trans, replaced the band and all was good!
 
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