Friend of mine has a 04 an we are going to pickup a 40' 5th wheel camper wt 13000lbs for my son who's 06 mega cab trans is down wateing on a Goerend . I did not realize that when you select Tow Haul in these 04's it locks OD out . This friend spoke with another 04 or 05 trk owner who told him that a reptable transmission shop told him that anytime you pull a heavy load such as this camper you put it in Tow Haul an leave it there even on level ground ? This trip will be from Little Rock Ark to east Tenn up near Bristol 600 mi. So there will be plenty of grades too pull that will require Tow Haul no doubt.
I realize if the truck starts shifting alot on its own it would need to be in Tow Haul an leave it there until everything levels out . But i'm thinking on level an rolling terain stay in OD an keep your speed up enough an it shoud not hurt a
a thing . I don't know what yr they up graded the 48 RE to have OD when your in Tow Haul ? So anyway what advise can you long haulers give me on this .

 

I use tow haul when I'm driving slow or in town. If I'm over 60, I let it eat.

That being said, I have a built tranny. Watch your tranny gauge.

 

Well this one only has a warning light I believe . Is your trans stock or beefed up ?

 

My 05 has O/D in TH mode. In this mode, it also locks the TC in 2nd gear, 3rd and O/D.

 

Thanks pdogg now that answers that question for me .

 

If the truck you are referencing is an 04, it will lock it out O/D while in T/H.

That is fine. Use it.........but once you are up to highway speed and can run enough rpms to keep the motor happy (1800-2000ish) then take it out of T/H and it will go into O/D.

On 05 trucks, they made a change that still let it go into O/D even in T/H. It won't allow you to lock O/D out like on 04.5 and before trucks. I believe in 06 you could push T/H twice....once to engage it and again to lock out O/D.

IN my case, I have an 04.5. So I use T/H starting off anytime im towing heavy and then disengage it at highway speed. Im sure your buddy's 04 will be the same.

..

 

Just got home from the trip truck did fine , I ran OD in the rolling stuff an TH in the hills . My question
is if this trans is called a 48RE ? I like the way it shifts better than my 47RE in my 01, although locking out OD is the same . So if I were looking for a 05 with auto it would be a deal breaker for me . Actually
except for the new trucks with the 6 spd i,m begining to think a 6 spd
manual is what i'd rather have .

 

NOT trying to hijack this thread or muddy the waters--BUT my 04(305/555)
will lock in tow-haul past 50 mph. NOT using the mystery switch either.
I know it is not supposed to do that BUT?????????????? Iknow it is not my imagination either, was pulling a hill in TH last week end . I thought it was only 04.5?????????????
Anyone else experience this????????? KINDA confusing...................