are 47re autos weak?

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NewMy 01 Cummins made 329,000 kilometres b4 I rebuilt the tranny. The lock up clutch was slipping in the torque converter when pulling. So I then went thru the tranny. I pulled everything in overdrive. Kim

Sorry that was a Quote from Kim. Not me. I messed up. Sorry.
 
Hellrats said:
Listen, I'm not here to tell you what to do I'm just telling you what has worked for me over the years. There is lots of stuff on Google. It's not a bad transmission and that is my opinion.
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I have a 47re in my 01Ram3500 v10 4wd dually. I bought it used, so I don't know the history on it. It has 210k miles on it. I really like it, but the trans just started leaking at the front pump, so I'm going to have to get into it. The trans has been rebuilt at least once, because the case has been painted & it has a nationally recognized rebuild tag on the side of it. I can't recall the rebuilder's name right now, but they are more familiar to me as an engine rebuilder than tranny guys. Anyway, when I looked online, I was just surprised how many negative stories were online about the 47re, thus the reason for me posing the question on this thread.
It makes sense that many diesel owners have had problems after boosting output on them.
 
It's kinda like putting a 340 in a 66 Dart with a 7 1/4" rear and then wondering why that POS rear broke. Everything is designed to handle a specific HP and torque.
 
My truck is bone stock. No power adders, nothing. IMO it’s not a great trans in stock form. Maybe a few thousand in billet parts from Goerend Trans will do the trick if I rebuild it, but autos are a lame duck transmission anyway.
It really needs a manual.
 
mopardude318 said:
My truck is bone stock. No power adders, nothing. IMO it’s not a great trans in stock form. Maybe a few thousand in billet parts from Goerend Trans will do the trick if I rebuild it, but autos are a lame duck transmission anyway.
It really needs a manual.
Click to expand...
All I can tell you is I’ve had a 95 with a 46RE, a 2003&2004 with a 47RE, a 2007 with a 48RE and a 2018 and 2020 now with a 68RE. I’ve never had trans trouble with any of them. Thou I’m anal about service.
 
rustycowll69 said:
47re's are mostly just 3spd 727, with an extra planetary hung off the back of the case, right? So why do they have the reputation as being weak? I mean I don't remember people complaining about weakness when 727's were behind 440's, or Hemi's, which weren't slouches. So why are the 47re's considered weak behind 5.9L magnums, or the v10's? please be as specific as possible.
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I have a 1996 Dodge Ram 2500 with a Cummins 12 valve.
I bought the truck 2nd hand knowing the trans was broken.
I do not know the history of the truck, but I can tell you there was a fifth wheel hitch on the truck.
I rebuilt and upgraded the trans myself after doing extensive research on this trans.
Upon tear down I found the following.
2nd gear band had no lining left whatsoever.
The engine had a terrible vibration when I got the truck that turned out to be a broken torque converter, loose elongated torque converter bolts with the flex plate bolt holes badly worn.
The boost valve spring clip was broken which probably failed the torque converter.
There was a return spring for a valve in the valve body that was broken as well. The biggest scariest about to fail component was the the fine teeth on the forward clutch friction plates were all bend over and about to completely round over. Think about that for a minute.

The owners manual shows that at 100,000 miles that Chrysler replac d the first failed trans under warranty. I bought the truck at 238,000 miles and the 2nd trans was failed.
I rebuilt the trans knowing I would eventually tow fairly heavy.
I put in the following.
A sonnax one piece billet input shaft.
An Sfi approved flex plate that is much thicker than stock
A triple disc lower stall (1650 rpm) torque converter.
An 11 lobe higher volume pump gear set from a 48re that gets the line pressure up very fast at low rpm.
A special thicker Sonnax front clutch seal to fix the machining defect
In the seal groove in the front drum that was machined to deep and did not always allow the front clutch to apply.
A stator from a 48re that has the additional torque converter seal ring to accommodate aftermarket triple disc aftermarket converters
That are actually all made for 48re and not 47re.
Thin redlined forward clutch plate with the upgraded fine tooth design from a 48re and the matching planetary hub.
All other clutches use the thin clutches to increase the clutch counts by 1 including the overdrive.
An aftermarket 6 pinion aluminum rear planetary and a 6 pinion steel overdrive planetary.
An aftermarket rear overdrive clutch support housing.
I drilled the rear cooler passage in the case oversize to get more oil flow to the rear support.
A bolt in rear sprag
A new solid not flex red line 2nd gear band with increased lever from 3.8 to 4.2 to get more holding power.
A new 800 lb overdrive clutch spring from the aftermarket and the new improved overdrive pressure plate and Torrington bearing assembly as the stock ones bend.
Also the rear cooler line retention clips can blow out from the plastic one melting from heat. There are upgraded ones available.
A complehte trans go tfod diesel specific shift kit which fixes all the failure points in the valve body and most importantly raises the line pressure substantially without shifting to harsh.
A Sonnax pressure regulator valve that charges the converter in park.
Sonnax coated thrust washers throughout.
I also installed a mag hytec deep pan.
Also upgraded the dipstick from an "O" ring type to the newer boot type to fix the constant leak.
Also I installed a sunshell from a 48re that is a heavier gauge stamping than the 47re and an absolute must is one of the aftermarket governor solenoids.
I used the Dnj model that gives the ability to lockup in 1st and 2nd gear.
The stock governor solenoid is a very common failure on all this series of trans that can cause all kinds of erratic shifting and can cause this trans to go into limp mode and stay stuck in 3rd gear. Apparently the stock solenoid cannot handle the line pressure because it is too small. Most of the aftermarket ones use a larger Borg Warner from a Gm trans that is reworked for the Chrysler.
The trans shift very nice and firm and works perfectly, but until my race car is ready to go I have not towed with it yet.
Theses trans do have lots of problems imho.
 
Last edited:
Duane said:
I have a 1996 Dodge Ram 2500 with a Cummins 12 valve.
I bought the truck 2nd hand knowing the trans was broken.
I do not know the history of the truck, but I can tell you there was a fifth wheel hitch on the truck.
I rebuilt and upgraded the trans myself after doing extensive research on this trans.
Upon tear down I found the following.
2nd gear band had no lining left whatsoever.
The engine had a terrible vibration when I got the truck that turned out to be a broken torque converter, loose elongated torque converter bolts with the flex plate bolt holes badly worn.
The boost valve spring clip was broken which probably failed the torque converter.
There was a return spring for a valve in the valve body that was broken as well. The biggest scariest about to fail component was the the fine teeth on the forward clutch friction plates were all bend over and about to completely round over. Think about that for a minute.

The owners manual shows that at 100,000 miles that Chrysler replac d the first failed trans under warranty. I bought the truck at 238,000 miles and the 2nd trans was failed.
I rebuilt the trans knowing I would eventually tow fairly heavy.
I put in the following.
A sonnax one piece billet input shaft.
An Sfi approved flex plate that is much thicker than stock
A triple disc lower stall (1650 rpm) torque converter.
An 11 lobe higher volume pump gear set from a 48re that gets the line pressure up very fast a low rpm.
A special thicker Sonnax front clutch seal to fix the machining defect
In the seal groove in the front drum that was machined to deep and did not always allow the forward clutch to apply.
A stator from a 48re that has the additional torque converter seal ring to accommodate aftermarket triple disc aftermarket converters
That are actually all made for 48re and not 47re.
Thin redlined forward clutch plate with the upgraded fine tooth design from a 48re and the matching planetary hub.
All other clutches use the thin clutches to increase the clutch counts by 1 including the overdrive.
An aftermarket 6 pinion aluminum rear planetary and a 6 pinion steel overdrive planetary.
An aftermarket rear overdrive clutch support housing.
I drilled the rear cooler passage in the case oversize to get more oil flow to the rear support.
A bolt in rear sprag
A new solid not flex red line 2nd gear band with increased lever from 3.8 to 4.2 to get more holding power.
A new 800 lb overdrive clutch spring from the aftermarket and the new improved overdrive pressure plate and Torrington bearing assembly as the stock ones bend.
Also the rear cooler line retention clips can blow out from the plastic one melting from heat. There are upgraded ones available.
A complete trans go tfod diesel specific shift kit which fixes all the failure points in the valve body and most importantly raises the line pressure substantially without shifting to harsh.
A Sonnax pressure regulator valve that charges the converter in park.
Sonnax coated thrust washers throughout.
I also installed a mag hytec deep pan.
Also upgraded the dipstick from an "O" ring type to the newer boot type to fix the constant leak.
The trans shift very nice and firm and works perfectly, but until my race car is ready to go I have not towed with it yet.
Theses trans do have lots of problems imho.
Click to expand...
wow. how much did the parts alone cost for that? Do you remember where you purchased all that stuff?
 
rustycowll69 said:
wow. how much did the parts alone cost for that? Do you remember where you purchased all that stuff?
Click to expand...
well I got a really good deal on the converter for $500.00 Canadian.
It was removed from another truck that was written off for parts.
The billet input shaft was I think $700-800 US dollars.
I built it quite a few years ago, but I probably have about at least
$2500 or so in it. Most of the parts and info was from Ptac I think they are called. They were also very helpful with explaining the
Various changes between the 47re and the 48re.
The shift kit from trans go was not your standar shift kit either.
It is diesel specific and has upgraded replacement parts for all the stupid little springs and clips that fail on those transmissions.
 
Duane said:
well I got a really good deal on the converter for $500.00 Canadian.
It was removed from another truck that was written off for parts.
The billet input shaft was I think $700-800 US dollars.
I built it quite a few years ago, but I probably have about at least
$2500 or so in it. Most of the parts and info was from Ptac I think they are called. They were also very helpful with explaining the
Various changes between the 47re and the 48re.
The shift kit from trans go was not your standar shift kit either.
It is diesel specific and has upgraded replacement parts for all the stupid little springs and clips that fail on those transmissions.
Click to expand...
One more question. It seems like many of the upgrades for the 47re are based on 48re parts. Would it be possible to just swap in a 48re behind my v10? or are the electronic controls incompatible? One of the reasons I ask, is because it seems the 48re's are more common to purchase used.
 
rustycowll69 said:
One more question. It seems like many of the upgrades for the 47re are based on 48re parts. Would it be possible to just swap in a 48re behind my v10? or are the electronic controls incompatible? One of the reasons I ask, is because it seems the 48re's are more common to purchase used.
Click to expand...
The 48re is a better beefier trans in some key areas.
There is a version of the 48re that uses an electric throttle control.
If you want to swap, try to find an earlier 48re that does not use that throttle control.
 
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