Odd 48RE tranny shift

Coming back from the cool north to Florida my 05 Dodge diesel started running a bit warm. It was not overheating just a little hotter than normal. My temp. gauge usually sits just in the center line or even a bit to the left. I always run in Tow/Haul mode when pulling. I kept an eye on the gauge and it rose to just above the normal center line.

I had the same thing happen at around 100,000 miles. It was the radiator fan clutch. Replaced clutch; fixed the problem.

Hi,

It might be in the tow/haul mode, it downshifts when you are leaving the freeway and not on the gas to help save the brakes.

You might also hear the fan clutch kick in, it does sound similar to the engine reving way up in RPM's. Many times when I leave the freeway in my motorhome, if I get stuck at a light, the heat from the engine will build up in the radiator, and the clutch will kick in for the first 15 seconds of driving.

When the clutch kicks in, then the fan is run 1:1 with the water pump speed. Normally the fan is idling, so it might turn 1/4 to 1/3 the speed of the water pump that it is mounted to. It makes much more noise when engaged.

Have you washed the radiator lately? You might have a layer of dirt that is preventing the heat exchange. Wash with a garden hose, and see what comes off it.

Fred.

I don't believe that is normal behavior for an 05 like it is for an 06.
You should post your question on the Turbo Diesel Registry, There are some excellent auto trans guys there and you will get some helpful advice. There's even a thread going on right now about the s/w change avail. for 05's.

Some bean counter had a fuel saving (bad) idea.....

2005 Dodge 48RE transmissions are the *only* year that has this *unique* feature:

Besides changing the shift points......
Pushing the tow/haul button on the 2005 Ram will lock out OD - *until* you press the accelerator - then it will shift back to OD (and remain in OD).

TWO things Tow/Haul on a 2005 does:
1. Changes shift points.
2. *Temporarily* locks out overdrive.

If you start (say from a dead stop) under load in TH, OD will stay locked out - *until* the computer decides (less load) it's time to shift into OD.
When that happens - it stays in OD - until you play the "button game" again.

Prior to the 2005 - pushing the TH button, locked out OD - until *YOU* canceled it.
Really just an OD "on/off" button.
For 2006, it changed to one push for Tow Haul, 2 pushes for OD lockout.
(or vice-versa).

Soooo - lots of strain on the Torque Converter for 2005s.
"Could be" (along with other things) the source of overheating.
Note: even the tranny folks say the '05 Trans cooler is way more than adequate.

I am re-considering the flash - as my 48RE went south at 80K miles.
(Original owner, not many towing miles, well taken care of, etc., etc)
Previously, I thought I would rather have the TH option - than true OD lockout.
Now I'm on the fence on that one!

BTW - BD (part #1031350) makes a converter to do the same thing as the 2006's for towing or running an exhaust brake.
About $200. - or if you're electrically talented, you can do the same on "the cheap" (the "mystery switch").

Google: BD Overdrive Lockout Switch for 2005 Dodge".
One of the retailers has the BD pdf on their site - which explains how it functions.

And - Spend some time on the various Dodge Diesel forums - you have to "filter out" the un-informed - regarding the "unique" 2005s.

Great source of *reliable* info on several of those forums is poster/moderator "cerberusiam".

Good luck..;)


~

The Dodge 48RE's have been plagued with this issue since they we first introduce back in 1998. I recently experienced the same issue coming back from Vacation in early August. Knowing my truck since it was new, and buying from the original owner, I new the transmission with 70k was on borrowed time.

After having the truck at a highly recommended local Diesel Performance shop, the shop manager / tech, gave me the bad news, Torque Convertor failure. He said if I continued to drive/ tow, it would grenade a perfectly good Core for rebuilding and potentially be paying another $1700 for not having a rebuild able Core.

These high performance diesel transmissions from BTW , Suncoast, and ATS will run you $4-$6K with the convertor and that's with a good core to exchange.

The shop I had my truck at, builds Diesel performance trucks for competitions.He has an in house transmission rebuilding shop, state of the art, with both a Transmission Dyno and Truck Dyno, sterile clean assembly room and unbelievable Transmission machining center. He used all Suncoast internals, billet shafts, multi disc Billet Torque Convertor, and Valve Body. Cost me just under $4,000 and 2.5 weeks without the truck. It tows great, my engine temps dropped 20 degrees and fuel mileage went up by 3 mpg. The best part is I don't loose any speed on the hills, maintains within 2 mph.

All in all I have spent nearly $9k in my truck over the past year, injection pump, lift pump, brakes, tires, TPS, Alternator and Batteries. Its an 02 with 73K miles. I bought it two years ago with 47K miles for $10,500 with nearly $20K in it, I still think its better than $65K for a new one :)

Nascar24,

The Dodge 48RE's have been plagued with this issue since they we first introduce back in 1998.

Don't think so as they did not come out until around Feb./Mar. of 2003, I tell you this because my 03 with the HO motor I ordered in Sept of 02 did not arrive until early March of 03, one could only get the HO with the 48re all others still used the 47re.
Don't know for sure but I thank they made a upgrade to the 47re about the same time as they went from the 12 to 24 valve motor 1 Jan. 1998.

ol Bombero-JC wrote:
Some bean counter had a fuel saving (bad) idea.....

2005 Dodge 48RE transmissions are the *only* year that has this *unique* feature:

Besides changing the shift points......
Pushing the tow/haul button on the 2005 Ram will lock out OD - *until* you press the accelerator - then it will shift back to OD (and remain in OD).

TWO things Tow/Haul on a 2005 does:
1. Changes shift points.
2. *Temporarily* locks out overdrive.

If you start (say from a dead stop) under load in TH, OD will stay locked out - *until* the computer decides (less load) it's time to shift into OD.
When that happens - it stays in OD - until you play the "button game" again.

Prior to the 2005 - pushing the TH button, locked out OD - until *YOU* canceled it.
Really just an OD "on/off" button.
For 2006, it changed to one push for Tow Haul, 2 pushes for OD lockout.
(or vice-versa).

Soooo - lots of strain on the Torque Converter for 2005s.
"Could be" (along with other things) the source of overheating.
Note: even the tranny folks say the '05 Trans cooler is way more than adequate.

I am re-considering the flash - as my 48RE went south at 80K miles.
(Original owner, not many towing miles, well taken care of, etc., etc)
Previously, I thought I would rather have the TH option - than true OD lockout.
Now I'm on the fence on that one!

BTW - BD (part #1031350) makes a converter to do the same thing as the 2006's for towing or running an exhaust brake.
About $200. - or if you're electrically talented, you can do the same on "the cheap" (the "mystery switch").

Google: BD Overdrive Lockout Switch for 2005 Dodge".
One of the retailers has the BD pdf on their site - which explains how it functions.

And - Spend some time on the various Dodge Diesel forums - you have to "filter out" the un-informed - regarding the "unique" 2005s.

Great source of *reliable* info on several of those forums is poster/moderator "cerberusiam".

Good luck..;)


~

My 05 does not temp lock OD out. TH changes the shift strategy and also allows the TC to lock in 3rd. The jump from 3rd to OD with the TC locked is big so it holds it in 3rd (TC locked) longer until around 55 MPH before it will let it shift. Once it's in OD it will hold it with the TC locked down to as low as 40.

I love the way my stock/factory 48RE works and I have been throwing high HP at it for years.

My 05 does not temp lock OD out. TH changes the shift strategy and also allows the TC to lock in 3rd. The jump from 3rd to OD with the TC locked is big so it holds it in 3rd (TC locked) longer until around 55 MPH before it will let it shift. Once it's in OD it will hold it with the TC locked down to as low as 40.

I love the way my stock/factory 48RE works.

I also think the stock 48RE does a good job shifting. In addition to what you have shared, I like the way it can be used to shift down on a long downgrade. Not a great amount of back pressure but enough to notice and often just enough to keep the feet off the service brakes. At 130,000 I have had no issues with mine. I think the OP's issue of the temps being a little higher is the fan clutch. Very similar to what happened to mine at 100K.

jmtandem wrote:

My 05 does not temp lock OD out. TH changes the shift strategy and also allows the TC to lock in 3rd. The jump from 3rd to OD with the TC locked is big so it holds it in 3rd (TC locked) longer until around 55 MPH before it will let it shift. Once it's in OD it will hold it with the TC locked down to as low as 40.

I love the way my stock/factory 48RE works.

I also think the stock 48RE does a good job shifting. In addition to what you have shared, I like the way it can be used to shift down on a long downgrade. Not a great amount of back pressure but enough to notice and often just enough to keep the feet off the service brakes. At 130,000 I have had no issues with mine. I think the OP's issue of the temps being a little higher is the fan clutch. Very similar to what happened to mine at 100K.

Yes, they are known for the clutches to go out.