47re missing first and reverse

Posted By: 1976Fury

47re missing first and reverse - 02/03/13 03:15 PM

I havent torn into this yet but im assuming its a rear band problem? It went out just before I went back to work so I have no access to it for a bit. Any insite?

Posted By: WO23Coronet

Re: 47re missing first and reverse - 02/03/13 07:50 PM

The issue I had with my Ram was that it wouldn't go into reverse, turned out to be the rear band apply piston/servo seal was SHOT! Here's the link to the fix and a better description of the problems I was experiencing:
https://board.moparts.org/ubbthreads/show...e=0#Post6860892

Posted By: John_Kunkel

Re: 47re missing first and reverse - 02/03/13 09:08 PM

1st gear in Drive or in the "1" position or both?

Posted By: 1976Fury

Re: 47re missing first and reverse - 02/05/13 08:40 AM

Both. And thats the other thing I will check. I hear its common for then servos to get cocked in the bore and self destruct

Posted By: cascius

Re: 47re missing first and reverse - 02/05/13 06:48 PM

Before you drop the pan I'd put a pressure gauge on it and see if you have any line pressure. The low/reverse band only comes into play in reverse and in manual 1st. When you put it in "D" the rear one way clutch holds the drum to activate first gear. If it were a band or servo issue you should still have forward gears when in "D".

Posted By: 52savoy

Re: 47re missing first and reverse - 02/05/13 07:17 PM

Quote:

Before you drop the pan I'd put a pressure gauge on it and see if you have any line pressure. The low/reverse band only comes into play in reverse and in manual 1st. When you put it in "D" the rear one way clutch holds the drum to activate first gear. If it were a band or servo issue you should still have forward gears when in "D".

I posted the same problem with my Ram SST a few weeks ago. That being said, he already knows there is a problem and IMO, putting a gauge on it is a waste of time and money if he has to buy one. Pull the pan and check how much slop is in the lever(s). No doubt.. a bunch. You can air check it the servo with the vb off, using the servo port(s)
The servo piston was busted on mine and updated front and rear to Superior Super servos. Also went with a 4 ring billet accumulator.
I found other problems with the tranny so it's on the bench getting more updates..bands, vb mods..

Posted By: John_Kunkel

Re: 47re missing first and reverse - 02/05/13 07:32 PM

Like cascius said, if there is no 1st gear in the Drive position the band isn't the sole problem.

Posted By: 52savoy

Re: 47re missing first and reverse - 02/05/13 08:05 PM

yeah..

I was thinking reverse only.

Posted By: cascius

Re: 47re missing first and reverse - 02/05/13 08:23 PM

Quote:

I posted the same problem with my Ram SST a few weeks ago. That being said, he already knows there is a problem and IMO, putting a gauge on it is a waste of time and money if he has to buy one. Pull the pan and check how much slop is in the lever(s). No doubt.. a bunch. You can air check it the servo with the vb off, using the servo port(s)
The servo piston was busted on mine and updated front and rear to Superior Super servos. Also went with a 4 ring billet accumulator.
I found other problems with the tranny so it's on the bench getting more updates..bands, vb mods..

If he only had a no reverse problem like yours was displaying, and still had all forward gears then you would be on the right trac. Also, the third comment in your thread was "should have checked pressures". Anytime I have worked on a transmission issue this was always the first thing you did. It's kind of like checking to see if a car has fuel when you're diagnosing a no start condition. It's vital information. I think we also need some more info from the OP. Is this behind a gasser or diesel? Did this happen overnight/instantly (went out to leave one morning and wouldn't move) or has it been having issues for a while? Does the engine rpm reduce when put in gear like it has a load on it, or does it stay constant?