?'s on Towing in O/D

[JEly]

I am wondering what the general consensus is towing in O/D. I have a 30 TT and I usally tow in O/D with no problems------transmission doesnt hunt or downshift at all. I set the cruise at 65 and go but I am wondering with the 315's if the rpm's are too low-------about 1700-----just tryin to get a idea before something goes wrong.



Thanks

JIM

 

[fox]

This is the problem with our auto"s. The spread is too wide between direct and OD. A auxillary OD will allow you to split the two gears.

Our trans need a minimum of 1900 rpm to get enough oil flow to hold up.

 

[Snow man]

i think you' d be fine on the flats,but kick it out of OD on hills, the auto generally doesnt last as long when kept under 1750 and pulling hard.

 

[fox]

One more thing, with my mods, I have pulled 8,000 enclosed trailer thru the Chattanoga area at 60 mph which is about 1600 rpm. It wasn't smart but I got away with it!!

I know, It wasn't anything at all like you guys pull in the Rockies. !!!

 

[cwsoules]

My 4:10 allows me to tow in o/d at about 2000. My DTT Smart Box allows me to set the O/D shift point to 57 mph to ensure that I have 1800 rpm before going into o/d.

 

[JEly]

I kind of wish now I would of got the 4:10 gears--------------I think with the 315's it still would of been in the 3:90 range.



Jim

 

[Snow man]

i have a set of 315s and 285s on different rims, the 285s are much better for towing. I dont like the squishy feeling 315's give with only a 16" rim for towing. The rpms are perfect for towing at 65-70 2000-2200 with 285 tires.

 

[y-knot]

In the flats towing in OD isn't a huge problem, the strain on the TC isn't excessive. Area's like the smokey mountains, on the other hand might be a problem, like the poster before mentioned, keeping the rpms up is critical. Guy with 3. 54 (city) gears, will be fourced to tow with OD off more offten then those with 4. 10 (real) gears. Also watch the crusie control, it is a bad ideal for towing. When it adds fuel, it adds way to much at once, and in many situations it will over power the TC, even clutch for the manual guy's. The key to keeping the automatic alive while pulling is to be smooth, on a off the throtle, while going thru the gears, take-offs. The engine should not be allowed to lug much, the higher the rpm's the better oil pressure, which amounts to more grip in the TC, and keeping the momentum up keeps the strain down. I think anything over 6,000lbs, requires the most attention, and the higher you go from there, the smoother you have to be. I have always been able to tow with the OD on for atleast 95% of the time while on highway. I turn the OD off in and around town, just to hard on the thing always locking and unlocking, builds alot of heat. The addittion of larger then stock tires is also a bad ideal for towing, it effectively raises your rear gear, which ='s more stress and heat. I would recomend a good aftermarket extra capacity transmission oil pan, they increase the oil volume and the extra fins adds in cooling. TheDodge transmission is already marginal, so anything you can do to help it along would good, and will pay dividens later.

 

[DMcGalliard]

O/D concerns???

Hi,

I have a 98. 5, 3500, 4x4, LS 4. 1 with 70k miles, 60k towing a 15k fifth wheel all over the USA, much of the towing has been in O/D, probably 50k miles and some of those miles I may have lugged(below 55). I have not had a problem with the transmission, the O/D gears are probably the stronges gears in the transmission.



I did replace the VB and torque converter with BD stuff. The truck has VA, boost mod and 275 injectors. I recently dynoed the truck at Jannetty Racing and it dynoed 265hp and 595 ftld of torque. I run AMSOIL ATF in the transmission and keep it clean. The transmission is strong with the BD mods and we did the dyno in 3rd not O/D, so the transmission will hold 265hp.



I had Jannetty add 4in pipes and the FASS system, the lift pump was real weak. Jannetty does excellant work and he does what he promises. He has an excellant shop in Waterbury, Conn.



So, it is OK to tow in O/D!!!!

 

[JEly]

When I tow I will keep it out of O/D until I hit 60 or so and then I put it on and set the cruise. I'm just wondering if I keep it out of O/D what rpm range is ok? If 1700 is to low is 22/2300 too high when towing.



Jim

 

[Joe G.]

You can run these engines at 2400 until you get tired of it. No problem.

 

[Matt400]

Originally posted by JEly

I kind of wish now I would of got the 4:10 gears--------------I think with the 315's it still would of been in the 3:90 range.



Jim

I was wondering what gears you had. I have 3. 73's and 285 tires and tow 6000 in OD fine. If I were to go to 315's then I doubt I would ask the engine to pull in OD.



IMO 315's & 4. 10's = good towing.

285's & 3. 73's = good towing.

 

[JEly]

I had to take the TT in for work and on the way home I decided to see what difference there would be not being in O/D and this is what I found--------------Driving at 65 and O/D off rpm's were 2400 and transmission temp was 200* and climbing I only stayed there for a few miles. I then switched the O/D on I was doing 67 and rpm's were 1750 and transmission temp dropped to 180 and stayed there for the rest of my trip home which was about 30 miles. So I am not sure but if heat is a bad thing wouldnt it be bad to keep it out of O/D and tow?



Thanks

JIM

 

[Fireman Dave]

Jim,



Lock-up is what helps keep the transmission cooler. I don't understand why you saw the higher temps out of O/D unless the TC wasn't locking up. Another thing to consider is lower RPMs = higher EGTs. Higher RPMs shouldn't equal higher transmission temps if the TC is locked up. I think 2200 rpms or so is right in the sweet spot, but lower MPGs will result when not in O/D. 1750 feels like lugging it to me. If it's really flat, I'll shift into O/D, but I'm usually in 3rd otherwise. But I knew that going in when I ordered my truck with the 3:54 rearend.



Dave