View Full Version : The truth about overdrive

03-03-2004, 06:14 PM
All right everyone i'm confused. one time i here it's better to haul a trailor with overdrive on like normal driving. The next time i here its better with it off while hauling, what is it? I'm worried about my trans (2000 Explorer) it seems like it started to slip maybe. What is the correct way:( ;)

03-03-2004, 06:19 PM
I used to haul cattle. 120,000 miles a year. Ford PS with auto. Never took it out of overdive. Never had a problem. Pulled a 24' gooseneck with average of 9,600 -10,000 pounds of cattle.

03-03-2004, 06:44 PM
Overdrive on... It only kicks in when it needs to, so if it goes on you need to stop, lol:cool:

03-03-2004, 11:19 PM
From what several licensed mechanics have told me. When hauling a load like a trailer what usually happens is that on an automatic almost all vehicles shift to early and cause the engine to work extra hard on the tranny to get it's self up to the right speed. I've always driven in drive until it's near usually 90-100 KM/h about where the vehicle is set to shift to OD. Then shift to OD never a problem haven't had any problems with tranny's slipping yet I do the same in winter when I plow

03-03-2004, 11:22 PM
I usually turn my overdrive off when pulling trailers. Thats what I have always been told.

Metro Lawn
03-03-2004, 11:50 PM
Owners manuals for Ford, GM, and Dodge all recommend turning the overdrive off when towing or severe transmission damage may occur.

03-04-2004, 01:23 AM
190K on my 95 f-150. I towed with the O/D OFF with it every day during the lawn season for 4 years, and Its still running great today. Make sure you have a large "plate" style tranny cooler. You should also change the fluid anually.

03-04-2004, 04:47 AM
I turn it off unless I;m on a flat, higher speed highway

03-04-2004, 04:57 AM
The trans in SD and HD trucks are different. Much stronger.

In 1/2 ton trucks the OD should be turned off when pulling unless your at highway speeds. In town driving should have the OD off. The OD has less clutches in it. The going in and out under heavy load will kill them.

03-04-2004, 06:54 AM
As several have already said:

OD is ok for flat, highway speeds.

Pulling hills and in town should be out of od. Multiple auto shifting not good.

I think you should have a transmission cooler on anything, especially a 1/2 ton. Many of the 3/4 and 1 tons come with this from the factory.

Owner manuals say to change fluid every 35k. If you're towing a lot, more frequent changes is cheap insurance.

03-05-2004, 12:23 PM
well guess what had my trans flushed at midas now when i am going downhill and it shifts from first to second there is a power lapse does anyone know why this might be happening, all i need now is trans trouble. (only 48,000) miles

Let it Grow
03-05-2004, 04:19 PM
When you are in overdrive your transmission is spinning faster than your engine. It also means that you are using less torque (twisting force) This means that if you are pulling a load it will probably get fairly hot, and that is not a good thing for a tranny. Don't use overdrive when towing. Use it under normal driving conditions when driving on fairly flat roads.

03-10-2004, 09:55 PM
They may not have used the correct fluid. The incorrect fluid can cause drive-ability problems. Good luck.:confused:

Shady Brook
03-11-2004, 06:39 PM
If you talk to reputable transmission shops, they will not do a transmission flush. It is very dangerous, as it breaks alot of junk loose that can plug a filter, or vlave body. If midus did not change your filter, they are acting very foolishly. I would tell them what is going on. If it were me, I would change the filter, and have them reflush. You may have some blockage that a second flush my break loose. I would then drive for a while to see if it helped, and again change the filter to make sure it is not plugging with material. This is especially important if you have not changed fluid in a while. New fluid has alot of detergents that will break crud loose and can really cause problems. Changing fluid in the pan is normally the safest thing to do. Believe me, I know much of this from experience.

I think you are always safer to tow out of overdrive when in town towing, or in the hills. With a heavy duty trans you will have some measure of safety, but in the main you will prolong your tranny life if you are out of OD when driving slow or in the hills towing.

I would not want to tow a trailer all day long with an explorer, but if I did, I would not tow in overdrive. I have seen them fail in friends vehicles without towing, and they are not cheap to replace.

For what it is worth.

03-11-2004, 11:44 PM
jay thanks that was some great info. this happened last week and tues. i took my car to ford. Guess what bad valve body had to replace $560 Im just glad it wasnt more serious. i believe what you said earlier is exactly what happened, they flushed it and the new fluid loosed up grime and dirt and then it started to shift weird thanks for the insightful knowledge of the problem
p.s. i only tow minimul hours a week i know this is bad for an explorer though

Shady Brook
03-12-2004, 12:09 AM

Sorry to hear you took a hit on your other vehicle, $560 hurts, but you are right that it could have been alot worse. I hope you can avoid further expense with the Explorer. I just layed down $3000 for a trans and torque converter yesterday in fact. I have been talking to Transmission experts, from installers to designer/builders the past month and have had quite an education. Having just purchased a vehicle to find out it needed serious trans work was painful, but maybe what I learned will save me or someone else some hastle and expense in the future.

I wish you well.


03-12-2004, 12:19 AM
Standard transmission...no problem.