48RE tow/haul

[organicfarmer]

i have a 04.5 w/ the 48RE auto. i was wondering about the tow/haul mode. what does that change? shift points? torque converter lock-up?  i'm know that tow/haul mode locks out OD.   THANKS!

[CTcummins24V]

47re/48re are 4 speeds automatics. 1st, 2nd, 3rd, 3rd lock-up and 4th (overdrive/4th is locked). I don't think tow haul on dodges changes shift points. Like you said, the main purpose is to keep you out of overdrive (4th gear). So when in tow haul mode the transmission won't go higher than 3rd lock-up. I use tow haul when driving around town or when keeping speeds under 50-55 mph. These transmissions are known to shuttle shift/search for gears and will hunt between 3rd and 4th sometimes. 

[Mopar1973Man]

As far as I know it just drops from 4th to 3rd. For Tow/Haul....

[Wild and Free]

It locks out OD on all years EXCEPT 05, It also changed the lockup logic and points, it does hold lockup a lot longer before down shifts and on my 05 I notice on long down hill coasts it will engage lockup in lower gears to help with engine braking too.

[AH64ID]

The 05's can be programmed for a tow/haul or an OD off.

 

The 06-07's have 2 modes OD Off or Tow/Haul. 

[War Eagle]

It locks out OD on all years EXCEPT 05, It also changed the lockup logic and points, it does hold lockup a lot longer before down shifts and on my 05 I notice on long down hill coasts it will engage lockup in lower gears to help with engine braking too.

X2

 

I like the features of the tow/haul mode in the '05 and I use it all the time when I have a load on.  It is my opinion that using the tow/haul mode helps overall performance and economy.

[Wild and Free]

I have been contemplating the OD lockout box from BD for years but just have not pulled the trigger, I wish every time I am pulling heavy I had it but then it falls to the back burner again.

[Mopar1973Man]

So what exactly is the difference from old school OD OFF and the new tow haul mode?

[AH64ID]

It's not that way in all years, only 03-04.5

 

From the 06 manual. 06-07 are the same, and like I said 05 can be either.

 

http://dodgeram.info/tsb/2007/21-006-07.htm

 

When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting occurs,
press the “TOW HAUL O/D OFF” button once to
select TOW HAUL. This will improve performance and
failure due to excessive shifting. When operating in
“TOW HAUL” mode, 5th gear (if equipped) is disabled
and 2-3 and 3-4 shift patterns are modified. Shifts into
Overdrive (4th gear) are allowed during steady cruise
(for improved fuel economy) and automatic closedthrottle
downshifts to 3rd gear (for improved braking)
will occur during steady braking. Pressing the “TOW
HAUL O/D OFF” button a second time to select O/D
OFF will disable 4th and 5th gear completely, which
should eliminate any excessive transmission shifting.
The “TOW HAUL” or “O/D OFF” light will illuminate in
the instrument cluster to indicate when the switch has
been activated. Pressing the switch a third time restores
normal operation. If the “TOW HAUL” or “O/D OFF”
modes are desired, the button must be pressed each time
the engine is started.

 

 

 

So what exactly is the difference from old school OD OFF and the new tow haul mode?

 

Tow/Haul modifies shift points and line pressures, as well as some differences in closed throttle downshifting.

 

The TSB linked above talks a little about it.

[Wild and Free]

On the 06-07 it uses the same button in the end of the shift lever, you need to push it once or twice for which ever mode you want, on the 03-05 you just hit it once for tow haul mode, the 05 comes from the factory with tow haul, but they must have later released a flash to do either or which I did not know about. I only knew of the BD OD lockout box you can add on to the 05 to cancel od.

[AH64ID]

Yeah the 05 has a flash option that disables tow/haul and makes it a OD off like 03-04. I posted a link to the TSB above.

[dorkweed]

I thought the 48RE trannies were 4 speed.......................not 5 speed like in what John posted????

[Mopar1973Man]

I thought the model number specified the gears...

 

48RE = 4 Speed, 800 foot pound of torque (flywheel), R ???, Electronic.

[Wild and Free]

From visiting with tranny tech gurus the tranny term for 4th or OD lockup is actually considered another gear aka 5th or a lot of times they call it 4th and then 4th prime for od unlock or 5th for lockup or something along those lines. Those full blooded auto tranny guys have their own terminology, I have a hard time following in conversation some times when talking to them and have to slow them down and have them talk layman mechanic terms lol.

I think it has something to do with how many planetary sets are used for each gear as well to how they designate what they call each gear. My 2010 Hemi is a 5 speed but there is never a reference to gear 5 in any technical manual this goes back to X gear "Prime" ect.

[CTcummins24V]

Could be considered a 5 speed. In town driving for me is different. I do OD off and the transmission pretty much stays in 3rd, but doesn't lock because of all the stop and go. So 3rd lock up is almost like another gear, the rpms drop when it's locked too. I can distinctly feel 1st, 2nd, 3rd, 3rd lock up and 4th. I think when merging on the highway and you're on the throttle 3rd might lock automatically.

[AH64ID]

I thought the 48RE trannies were 4 speed.......................not 5 speed like in what John posted????

I didn't post anything about it being a 5 speed. 5th gear was followed by (if equipped). If equipped referrs to the 545RFE installed behind the Hemi.

The rest of the description is how OD Off and Tow/Haul works in 06-07. It is one button but two different features. Think of it more as a 3 postion toggle switch.

I thought the model number specified the gears...

48RE = 4 Speed, 800 foot pound of torque (flywheel), R ???, Electronic.

I know that is what the 4, R, and E stand for but that is the first I have heard of the 8, or corresponding digit, stand for torque capability. Maybe it's a new thing, but I don't think Dodge has always done that. Think about the 42RE. It is used in the 1500's behind the V6's which produces 215/235 in 2010.

Do you have a reference?

From visiting with tranny tech gurus the tranny term for 4th or OD lockup is actually considered another gear aka 5th or a lot of times they call it 4th and then 4th prime for od unlock or 5th for lockup or something along those lines. Those full blooded auto tranny guys have their own terminology, I have a hard time following in conversation some times when talking to them and have to slow them down and have them talk layman mechanic terms lol.

I think it has something to do with how many planetary sets are used for each gear as well to how they designate what they call each gear. My 2010 Hemi is a 5 speed but there is never a reference to gear 5 in any technical manual this goes back to X gear "Prime" ect.

While prime is a gear term used on some Dodge transmissions the 48RE is not one of them. The 48RE is a true 4 speed with no prime gear. 4th lockup is just that, 4th lockup. I am not a autotransologist but every one I have talked to will give you a brow beating for calling lockup in OD another gear. Lockup and gears are two separate functions. The 48RE can lockup in 3 of it's gears but generally just 3rd and 4th.

The 545RFE does have a prime gear and is he trans installed in your 2010, as well as many other model. The 545RFE actually has 6 gears. I am not sure what techincal manuals you have looked at but everyone I have looked at has info on all the gear choices of the 545RFE.

48RE

1st: 2.45:1

2nd: 1.45:1

3rd: 1.00:1

4th: 0.69:1

4th gear unlocked is still .69:1 just with converter slippage.

545RFE

1st: 3.0:1

2nd: 1.76:1

2ndP: 1.50:1

3rd: 1.00:1

4th: 0.75:1

5th: 0.67:1

You can see 6 actual ratios and prime is a different gear ratio.

Normal acceleration on a 545RE skips 2P. It takes a downshift under acceleration to get 2P. Some say it has to be a 4-2P, but the manual talks about a 3-2P. I don't have much time driving one so I couldn't tell you for sure.

I also understand the 545RFE and 45RFE to be the same transmissions with different programming to get 2 OD's. I think it has something to do with using the 2P gearing?????

Could be considered a 5 speed. In town driving for me is different. I do OD off and the transmission pretty much stays in 3rd, but doesn't lock because of all the stop and go. So 3rd lock up is almost like another gear, the rpms drop when it's locked too. I can distinctly feel 1st, 2nd, 3rd, 3rd lock up and 4th. I think when merging on the highway and you're on the throttle 3rd might lock automatically.

Yes the rpms will drop, as the tq converter is no longer slipping, but it isn't considered another gear as the ratio inside the trans doesn't change.

Since the 48RE is actually a 3 speed with an overdrive module it would be possible to engage the OD in 2nd (aftermarket wiring/brain) but that ratio would be useless at 1.0005:1.

[organicfarmer]

thanks all! could i use a lock up [manual control] on my 48re? 

i had talked w/ my trans. guy [todd @ bench tech trans. in terry hill 'south east' pa] he said 04.5 [?] has the cable to control shifts [?] the 05 has a box on the side of the trans. & that controls shifts ????? i really dont know what i'm typing    

 my question is , can i add a tc lock switch on my 04.5 that will not destroy my trans. if i or someone else is driving & forgets.............wich gears does it lock?

THANKS!!

[Wild and Free]

You could try something like this on yours.

 

http://www.dieselperformance.com/index.php/product/index/26P

[Killer223]

Chrysler Automatic Transmission Name Convention

Applicable to 1994+ Chrysler transmissions

• Forward gears - the number of forward speeds the transmission has.

• Strength designation - Chrysler's strength designation is an arbitrary number representing the transmission's strength on a scale of 1 through 9; the higher the number, the higher the transmission's input capacity. This number is not a direct representation of the transmission's maximum input torque capacity. A strength designation of "8", for example, does not correspond to a max input torque capacity of 800 lb-ft.

• Application - all Chrysler transmissions mated to the Cummins turbodiesel will have an "R" in the application designation, which stands for "rear wheel drive".

• Control type - An "H" in the control type corresponds to a hydraulically controlled transmission, an "E" for an electronically controlled transmission, and "FE" stands for fully electronic.

[Mopar1973Man]

I stand corrected but I was close...