Overdrive

[dhammond]

How come I can't tow in overdrive? I couldn't tow in overdrive with my Dakota either, but I was only pulling a pop-up camper then. Sure would help the mileage.

 

[Fireman Dave]

Here We Go

OK, I might as well get it started. I tow with OD off. With it off, you have a straight 1:1 ratio, thus the planetary gears aren't working. This is the best situation for the transmission. To me, this reduces the chance that the transmission will puke prematurely. Also - with my gear ratio - I find that the RPMs of the engine are in a much sweeter spot at 55-65 mph with it off (2000+ rpms). With OD engaged, it seems to be lugging at around 1600 at those speeds.



Now, many guys do tow with OD engaged. Personally, I don't like it. I have played around with it on flat runs, but the RPMs are just too low for my taste. A 4. 10 gear would be more comfortable with OD engaged, but I still believe you're running a higher risk of premature pukage. Not that it will definitely happen - I'm just trying to tip the odds in my favor as much as possible. I figure towing with OD off costs me maybe 2mpg - not enough to outweigh my previously stated reasons for keeping it off. My TT weighs about 6,000 lbs, by the way.



I hope this helps, and I'm sure there will be opinions on the other side - which is what this TDR thing is all about!

 

[LSMITH]

Over 60 MPH there is no reason to not tow in OD IMHO, if you are coming up on a hill that you cannot pull in OD then push the button and kick it down to D. I have no problem pulling at 1700 RPM in OD. If you ever have the situation that EGT is going up and boost is going down then DOWNSHIFT, you are lugging the engine at that point! Dave makes the point that the transmission will not hold the torque happily at 1700 or less and he is correct, but if you are running flat ground at 60 with 8 PSI and 900* in OD for example you will be fine. Abuse is very different from use, if you pound the torque at the transmission at low RPM it will DIE, if you run it conservatively in OD you will get the same life out of the transmission as towing in D and better MPG along the way. My honest opinion.

 

[GLASMITHS]

towing in OD

dhammond:



Hindsight only counts when you are correct. Long before I ordered my truck and trailer there was much research went on, as well as common knowledge. So when the time came I ordered the rear-end recommended for towing; as well as making sure there was enough left in the bread-box for a Gearvenders O/d. I lock out Dodge O/D and with the GV engaged it puts me between Dodge 3rd and Dodge O/D; rarely ever have to downshift and the rpm is about 2200; towing a 16500# 5vr I get from 11-14. 5 MPG Figured with a pencil-----------



Since you are not so equipped; my recommendation would be to stay out of O/D, except as LSMITH put it. No hills, headwind,ect.



This is for two reason, one, your specific fuel consumption is best on the 24V around 2000 rpm secondly, your transmission fluid preassure is accordin to rpm. Somebody will flame me on that; however that is my understanding; that is why BD has the pressure lock, so when you let off the peddle the pressure goes up?????



What I'm trying to say is that lower rpm does not necessarily translate into higher MPG.

 

[barryg41]

I made a trip, last summer, thru Texas, New Mexico, Colorado, Wyoming, South Dakota, Nebraska, Kansas. Oklahoma and of course Louisiana. I pulled 95% O/D off. I could not hold the hills or the cross wind, the cross wind was terrible thru northern Texas. The flats of Louisiana was the only time I used O/D.



My average speed was 68 mph at 2750 rpm's. The MPG's were for 4200 miles was 10. 5 avg. The noise in the cab was loud.



The Trans temp was 135 degrees in the mountain states and the rear end was at 175. When I got down to Oklahoma and Louisiana, the trans temp was in 150 range and the rear end temp was up to 225 degrees.



Now I have the PE EZ and have not pulled with it. But it has woke up the Cummins. We wanted to make a trip to Mexico but it didnt work out. I guess I will wait for the first trip to Destin to see how it pulls.



I pull a #9000 5er! If the rpm's drop below 2k rpm I stay out of O/D. It seems to make the drivetrain work and sound best.

 

[dalton4]

I'm using O/D very much as stated by LSmith. I use O/D if conditions are such that 60 mph can be maintained with light throttle (low boost,8-12#). O/D is turned off when headwinds or grades are requiring heavy boost.



Jerry

 

[chuck3]

Towing in O.D.

My TT only wts. around 7k. lbs so I do most of my towing in OD, take it out on hills that are steep and long but it will pull a lot of little ones with the EZ, have not had a strong enough headwind yet to cause downshift. I'm not saying this won't shorten the life of the transmission, it may I don't know.

 

[dhammond]

Overdrive questions

Thank you all for your replies. I haven't gotten the fifth wheel yet. Plan on getting a 27' Sunnybrook this spring.

 

[klenger]

We looked at the Sunnybrook 27RKFS (I think). Terrific floor plan. Got the Fox 27-5L with almost the same floor plan. I think either would have worked out fine for us.

 

[RedRamer]

I pull 6,500# TT in overdrive all the time. I find 1,750 rpm to be my sweat spot and that's at 110 kph (10 over the speed limit). On small to med hills I try and get a run at it from 120 kph - 2,000 rpm and can usually make the grade with a drop down to just below 1,600 rpm toping it. OD keeps the transmission temps down to 180. Still stock transmission btw.

 

[cwsoules]

Use of OD

I just finished a trip where I manually controlled my OD. Above 58 mph on flat ground I would tow in OD using cruise control set at 62 mph. When I anticipated that the trnasmission was about to shift out of OD, I would manually disconnect. This trip included a a tow on 101 South to Gilroy and then across the mountains to 99 and again South to Barkersfield. Later we towed South again on 99 to I-5 and across the grapevine. I had to closely monitor speed and the terrain to ensure that OD was used when possible. I got 12 mpg. Formerly when I towed with OD off I never got above 9mpg towing. During this tow I had the DTT VB and TC installed.



I just had the new DTT Smart Box installed and I am looking forward to using it and my new Pac Brake when I tow again.

 

[TKilgore]

Destin

barryg41, this is off the sub but where do you go in Destin and how often?



BTW, I tow in OD per Bill K's advise but I keep my rpms up (2000). Anything less and I don't seem to have the power so I slow down and turn off OD. I am hoping the comp and VB will help my curve some. Like the others have said, when facing a long hill or steep grade, head wind, etc. I down shift.



Tom

 

[barryg41]

Tkilgore... . We always go to the Holiday travel park. This will be our 25th year in a row. It's right on the beach and it is real nice. If you like the sand. The park is just on the other side of the business loop heading towards Panama City.



We usually go two times a year. Usually in mid June and then again just before school starts. We use to try to go on the July 4th week but even the ants stay away that week!

 

[Mpoland]

Towing in OD

I tow a 8-9K TT (depending whether the wife packs the entire house in it). With the 4. 10, I am not comfortable with the OD locked out. The revs on the engine are just too high, at highway speeds. In OD, I run 60mph@2000rpm... perfect.



I always figure if the trany takes a dump, then I'll get a bigger and better one from DTT. After all it's only about a $3000. 00 gamble... right?. . LOL

 

[Snow man]

I use OD when towing,above 55 mph,with 4. 1o's the truck tows great from 60mph,up to whatever you want to tow at. I usually tow at 70,which is 21-2200 ,ideal from how the engine sounds,it doesnt sound happy below 2000 with a load on it. im sure it isnt any good fro the auto either laboring it.