My uncle has a 2005 2500 CTD, 48RE slushbox, hes starting to realize they don't shift the best, and now borrowed my 08 to go to the mountains and really likes the 68RFE......
the question is this : is the a tuner out there that will allow him to tweak shift points/firmness with out costing an arm and a leg or adding more than the 50 hp he would like to keep it under?

truck is stock power and also has a pacbrake in it but for some reason he says he never uses the tow haul mode when pulling, not really a good thing I think but I'm pretty rusty on my 48RE stuff

thanks in advance guys

 

TOW/HAUL will do that for him to some degree.


47

 

On my 05 the tow haul button is a must!! It changes the shift points with a more postitive shift. It also will downshift if you start riding the brakes. Also when climbing steep grades and your speed drops below 35 mph, the owners manual tells you to put the shift selector in "2" and keep the speed above 28 mph and the torque converter will remain locked. I just returned from a trip in the West Virginia mountains where 9% grades are common. My transmission temp guage installed in the output line from the transmission showed absolutely no temperature gain on these sometimes 2 mile long pulls. I maintained 28/30 mph effortlessly.

Works like a charm and I cannot imagine towing without using this feature.

The 48RE transmission came out in 2004 models I believe and was a nice improvement from the 47RE. Mine has worked very well but you must use it correctly.

 

They came out earlier than that, my '03 has a 48RE

 

Ya, I was kind of shocked when he rolled in with a 26' living quarters horse trailer on and said he didn't use his tow/haul mode to pull it.

He was told that my 08 doesn't go anywhere with something that heavy tied onto it with out to/haul and that he was going to drive it like he had to pay to fix it if he hurt it......... haha

on a side note that may have something to do with it, it went to town to fix a CEL it had and came back as having a transmission throttle valve actuator problem so that may be the $670 lick in the pants he needs to use his tow/haul

 

Tow / Haul increases the line pressure in the valve body allowing for firmer shifts and better TC lock up power while helping to lower trans temps. Use it..

 

I changed the transmission filter for him while it was sitting around the yard and there was a lot of stuff stuck to the magnet in the back corner of the pan as well as a few brass or bronze colored little tiny shiny bits around and under the magnet, I warned him to use his tow haul button any time he pulls anything and that the shiny bits scared me a little even on a 240,000 km truck............ we will see if he listens

 

Update, CEL came back on, gutless as can be, same trans throttle valve code as before, going back to the dealer on wed.

my question is this, did he run it without the tow/haul mode long enough that he did some fairly severe damage to the trans clutches and converter and the shiny bits that were floating around in the pan became worse and now he's screwed up his shiny new month old throttle valve?

not my truck so I'm not losing sleep over it but I'm guessing he's going to need a built trans if he refuses to use tow/haul because he doesn't like the way it shifts

sorry that got a little rambly and long.....

 

I adjust the bands ever time I do a trany service, every 30k miles, I use tow haul even when I am not towing, all the time, up`s line pressure, she shifts great all the time, 132k now, and still shifts like when I bought it.

 

ya, I'm a big fan of the tow/haul mode, unfortunately my uncle has raced up lots of miles pulling this stupid trailer at 22,000 GCVW without tow/haul................

the one dealer he talked to said that the pP0483 fan speed code that comes up will "rob power from the other functions on the circuit and cause problems on down the line"

I find it hard to believe that the fan code causes the P1753 transmission throttle valve mechanical performance code and then the truck gets real gutless real fast and shifts like butt.

 

My 05 doesn't lock out overdrive like my 04 and I hate it. Even with tow/haul on its the worst shifting tranny I've ever driven. I saw where you can go to the dealer and they can change it to lock out od. I can't wait to get it reflashed

 

The 2005 48RE auto trans tow/haul logic is screwed up. You have a choice of OD lockout or tow/haul. You really need both.

Fortunately the aftermarket has the fix:

http://www.dieselperformance.com/ind...duct/index/28P

 

ok cool, thanks for the heads up on the lock out....il point it out to him and see what he says

 

I installed one of those and it works great. I hit it when the truck starts to bog in slow traffic. Also I always use tow/haul.