Hoping i can clarify this as ive been through it a number of times with my local transmission shop.

Sadly enough while on a camping trip this year my tranny decided it had enough while heading up a very steep loggin road.

Hauling a 10 1/2 Travelmate camper ive never had any issue before but for some reason the tranny decided to heat up and end my trip rather suddenly as the fluid ended up pouring out of it .

My truck is a 1996 Dodge Ram 2500 Laramie 5.9 cummins turbo Diesel

Full size all 1 ton running gear ,my father had actually purchased this truck brand new and had all the bells and whistles added onto this truck.


Now after having a complete tranny rebuild including new shaft ,Heavy Duty Torque converter , adding a shift kit etc i am still concerned about the proper usage of the overdrive button

Now when the button is pushed and the light is on the overdrive is disengaged

While having my camper on the transmission shop suggested i leave the overdrive engaged at all times unless going up some very hilly areas at which time i was told to disengage the overdrive .

Now with the camper off i have the overdrive feature disengaged at all times unless i reach around 75-80 kmh where i once again engage the overdrive .

So what i am basically asking am i using the overdrive feature properly ?

When and where should it be engaged or disengaged etc considering the uses while i have my camper on or off

Thanks for any and all information as this is kinda driving me nuts spending 3 grand in total which includes my 350 dollar tow from the bush on the initial breakdown i want to make sure that the over drive feature is being used properly

 

Drop out of overdrive whenever the engine is working to maintain speed -- better, just before it would. You really only want overdrive engaged when the truck is mostly unladen and cruising level or down-slope. However, if the engine is running hot from pulling a grade, stay in normal drive until the engine temperature has returned to normal. The higher RPM will help cool the engine more rapidly.

Around town where the overdrive unit would be shifting in and out frequently, disengage it. If you're in a hilly area, leave it disengaged rather than bouncing on the button for every rise and fall in the road. The goal is to have O/D on when you can leave it on for a pretty good length of time, and off when you cannot.

Welcome to the forum!

 

Overdrive should always be turned off whenever hauling a trailer or anything else that adds a significant amount of weight to the truck. That shop should have their head examined for telling you to keep it in OD all the time minus hills... I seldom ever use my OD, I switch it off and drive without it engaged for most of the time, until I get up to ~90 km/h. This is personal preference, it gives a little more power on tap, and I feel better about the trans cause it's not lugging right down a chuggin along in OD at 60 km/h haha... Been doin it for over a year now on this truck and the trans hasn't given me a single problem yet

welcome to df fellow canadian!

 

The Tranny shop ( 3 year warranty /50,000 miles on the tranny) suggested when i have the camper on while just cruising around town or on the highway etc with the truck i should leave it engaged .
The reason its bothering me is they also told me when i hit 85-90k to disengage it which is wrong i believe since it jumps the rpm/s up to 2200 etc .
I called them back regarding this and they then told me only if i was going up some extremely hilly terrain etc while loaded with the camper that i would want to turn the overdrive off.

So today after taking the camper of they had told to me just leave the overdrive off all the time but of course once your out on the highway doing 80k the rpm tend to be sitting above 2200 at which point i turned the overdrive feature back on and rpm and gear of course change letting the rpm run at around 1500

 

Diesels are a totally different game than a gas motor. My buddy hauled my truck home on a heavy *** trailer in OD the whole time. I would assume he was pulling 7,000lbs easy. His is a 24v 1998, His truck didnt miss a beat the whole ride home, and that was up many hills

 

I didint even notice the Diesel section :-( ,but yes mine is a Diesel maybe that why the suggestion to keep it in O/D the entire time the camper was on unless i was at or on some very large hill etc?

Only thing is i havent been away since i had the tranny replaced ,finally dropped the camper of today but have plans for the future to go away again .

Its a big camper 10 1/2 foot Travelmate basement model ,i'd have to look at the specs but i am guessing around 2200-2500 pounds dryweight.

 

My concern: The transmission doesn't know or care what's driving it. Running along in overdrive, the pump RPM is lower than it would be in normal drive, so the line pressures are lower, too, which means less clamping force on the clutches. Dropping it back into normal drive brings the line pressures up, increasing the clamping force applied to the clutches.

But, as always, live like you want to live.

 

For that trailer, I am surprised your truck even notices it is there.......

Now, bear in mind, all this reasoning is based on a gas engine....... though I really don't see how what is driving the trans makes any difference really.... anyway.... What kills your trans is heat. When driving around normally, your truck is fairly light (as these things go), and the engine/trans aren't working all that hard to toss it around, even up hills, if the PCM thinks the engine is being overloaded, (bogged down) it will downshift. So, unloaded, I leave mine in O/D all the time. (I don't do a lot of 'real' city driving, adrian is a podunk little town, and I avoid going downtown as much as possible.)

Now, when loaded.... your engine/trans are already working pretty hard, and running in O/D generates a fair bit of heat. Granted, the trans in your truck is a tad meaner than what is in the usual truck. (V8, auto...) But, heat is still heat, and will kill your trans regardless of what fuel is in the tank.

I would recommend a trans temp gauge. Trans running warmer than you think it should? Turn off the O/D.

 

I beleive the current trans temp guage is linked in with the dashboard truck temp guage but i am def considering getting a seperate mounted gauge to keep an eye on tempatures under heavy load

 

Like everyone else said, I run a gasoline Ram, but I never have O/D on when towing.