1st Gen Tudnda, Overdrive while Towing 3500lbs?

[zootjeff]

I know this has been discussed somewhat, but I'm still curious about other peoples experiences..

I have a 1st Gen Tundra which wasn't "really" designed for towing, if you read the user manual.. They don't really talk about how to use the Overdrive other then "Don't turn it off if you want to save gas".

So I have a 3500 pound travel trailer, and it tows it just fine. But my question kind of philosophical, should I use the over drive ever when towing?

Is it better for the tranny to never use overdrive? Or is it OK to tow in overdrive on a flat surface, slight decline, etc..

Basically I tow under the philosophy that I want the automatic transmission to shift when it's not under load, and if I'm coming to a hill, I typically will get it to shift right before the hill starts so that "I feel like" I'm putting the least load on the transmission. I also use the philosophy that I want the transmission to shift as little as possible.

My transmission has 120k miles on it and I want it to last as long as possible, so what kind of towing behaviors should I adopt? And how should I use/not use the overdrive disable switch?

-Jeff

[brtn540]

You always want to use overdrive when you are towing/hauling any type of load. It basically changes your tranny from a 5 speed to a 4 speed if I'm not mistaken as well as changes the shifting points so that your transmission doesn't have to work as hard to tow the extra weight. So make sure your overdrive is off while towing a load.

[Jodan]

I think you will notice the torque converter acts differently , seems to lock up quicker with the OD off. It makes things not slip as much as with no load driving it seems the converter really fluctuates the RPM's. I would guess this would be some of the reason to turn off the OD.

[tomhole]

Since it is a 2000, you have the 4 speed tranny. My philosophy is the tranny will tell me whether to use overdrive or not. If it is constantly shiftin in and out of OD, then I will turn it off. If it's happy in OD and stays there, then I will use it.

Tom

[Only Toyota for me]

Originally Posted by tomhole

Since it is a 2000, you have the 4 speed tranny. My philosophy is the tranny will tell me whether to use overdrive or not. If it is constantly shiftin in and out of OD, then I will turn it off. If it's happy in OD and stays there, then I will use it.

Tom

X2 on your response Tom. I did the same thing with my first gen tundra when i had it.

The TC does lockup too quick with OD off. Therefore, i always tried to use OD off most of the time so when i came to a hill and needed more power, i would just push the button and bing.....another 300 rpm's and a little more power.
Our trailer was a 23' 99 Terry weighing 4000 lbs empty. With this trailer i would need to be in OD off mode most of the time.

All i can say to the OP is; BE SURE TO SERVICE IT FREQUENTLY!!! Even a simple drain and refill every oil change would be a good practice. And if it's never been done at all, i would do a complete service on it.

[Herbicidal]

I have a 2001 Tundra 4x4 and I've been towing a 26' Outback travel trailer since October of 2003. "Scaled" weight of the trailer in camping trim (no water on board) is 5,600 lbs. I have a tranny temp gauge mounted to the 'A' pillar with the sending unit mounted in the tranny pan. I always tow with OD turned off unless I'm heading down a long mild grade with minimal throttle. While having nothing else to do while towing on a long flat section of Interstate 5 here in northern CA, I turned the OD on. I was cruising along @ 60 mph and the tranny temp gauge was reading approximately 180 degrees. This was on a summers day with outside air temp around 95 degrees. After a few minutes I observed the tranny temp climbing. Once it hit 200 degrees, I turned OD off and about 5 minutes later it was back to 180 degrees. It showed me the tranny was definitely working harder. I'm running Amsoil in the tranny with a larger aftermarket cooler and an in-line filter. I now have 126,000 miles on the odometer and we've towed to southern CA, the coast of northern CA, Oregon, Nevada, Idaho and Wyoming with not a lick of trouble.

Your trailer is about 2,000 lbs lighter, but even so, I would suggest leaving OD off unless you are heading downhill. Your tranny will appreciate it! If you're curious, it may be worth it to you to install a tranny temp gauge and see for yourself how the tranny temps fluctuate under load.

Happy camping!

[zootjeff]

Originally Posted by Herbicidal

I have a tranny temp gauge mounted to the 'A' pillar with the sending unit mounted in the tranny pan.

Hey, thanks for the tip! Can you tell me more? What kind of temperature gauge, how much do they cost, and where do you get them? Do you have any pictures? I'd really like to do that, I thought that would be a nice to have but didn't really know where to start.

-Jeff

[Herbicidal]

Hi Jeff,

Summitracing.com is where I bought the A pillar pod and the tranny temp gauge from several years ago.

Autometer 15412 'A' pillar gauge pod ($22.95 - unpainted):
Auto Meter 15412 - Auto Meter Pillar Gauge Pods - summitracing.com

Tranny temp gauges, prices and styles vary. Just make sure to find one that fits the A pillar pod. Also make sure it includes the sending unit.
Auto Meter, Gauges, Analog - summitracing.com

I have some pictures in my gallery. Feel free to check them out. I see that Summit Racing offers paint for the A pillar pod. I found a nice colored, textured paint at Lowes that pretty closely matched the interior of my Tundra. You can pull your ash tray out with the colored face and take it into the store for color comparison. You will need to decide whether you want the sending unit in the tranny pan or the rubber tranny line that goes between the front of the engine (it's a hard line that goes back to the tranny) and the bottom of the radiator. I did the rubber line method first, but finally went to the tranny pan method for the stability of the temp readings.

The tranny pan gives the most stable and accurate reading. However it also requires the most work as you have to pull the tranny pan and braze in a fitting for the sending unit to screw into. Another possibility is to replace the drain plug with a sending unit that doubles as the drain plug. I actually bought a 2nd tranny pan, had a fitting brazed in, then replaced the pan when I had the time to do it.

The rubber line method is almost as accurate on the temperature info UNLESS you are in stop and go traffic or other situations that dramatically increase under hood temperatures. Then the sending unit in the rubber line will absorb the extra heat and provide a false high reading. The other challenge with the rubber line method is that you must provide a ground for the sending unit or it won't work.

Let me know if you have any more questions.

[bill3508]

On the 4 speed overdrive is worthless with that kind of weight. I towed my bass boat yesterday and at 65mpg I was 3000 rpm's and it towed fine, turned overdrive on and at 62 mph was at 1800 RPM and you have no power. Only reason to use overdrive while towing is if the trailer and gear weigh 1500lbs or less.

[dogger]

I have a first gen Tundra and like you, I tow a trailer that averages about 3500
lbs when loaded. I specified the towing package when I bought my truck which
got me a rudimentry tranny cooler and stouter electricals.

I spent a lot of time transiting between NorCal and SoCal at 70 mph and
I could rarely turn on the overdrive. I had to upgrade the brakes, suspension
and engine to better deal with the towing demands and finally, many $$$s
later, my Tundra is a decent tow vehicle.

The transmission is one of the Tundra's weak spots and has to be coddled
to make it last. Conversely, if you strengthen the tranny (shift kit, etc.)
you run the risk of grenading the weak rear end, so just go with it.

I power flushed the stock fluid and replaced it with Red Line synthetic and
added a B&M tranny cooler with it's own dedicated electric fan (B&M 70297).
This helps with the extra heat from towing but is not a total fix. Like others
have said, keep the overdrive switch off while towing. You just have to put
up with the noise and lousy gas mileage.

dogger