What have you done to your Tacoma today? 1st Gen Edition

Anyone got a passenger tail light laying around?

new style lens



mine found a tree today

 

I have questions regarding my automatic transmission. Recently, I have been towing an enclosed 4 x 8 trailer, with a 4 wheeler inside, usually along with a bit of other camping/hunting gear. I've made several trips from upstate NY to W. Va., nine hundred miles round trip. On the next to last trip, as I was pulling a very steep gravel road, my transmission fluid temp light came on, just as I was about to top the hill. Needless to say, I pulled off and rested the beast for a while. Light goes off, and I continue on my way, nervously.

Arrived home without further incident. Did a drain and flush of the transmission. Had been approximately 75,000 miles since last. Fluid was quite dark. I decided to add a new ScanGauge II to more closely monitor. Next trip out was with a 5 x 10 flat trailer, with about 100 lbs on it, so not much of a load. I began pulling a long interstate grade, temp was about 160, overdrive as still on. As soon as the overdrive released, that first change of rpm of about 400 rpm, the temp started to shoot up by 5 or more degrees per second, and reached almost 250 by the top of the grade. Then as it locked back up the temperature began to fall, almost as fast, and was quickly back to around 180. At the next incline, I turned off the overdrive, where it now jumps about 900 rpm. However, now the temperature remained constant at whatever it was at the start. I experimented all the way on my trip, and the behavior was very consistent. Rapid rise if overdrive was allowed to disengage on its own, no rise if it remained locked (on very slight inclines) and no rise if overdrive was disengaged at the bottom of hills and mountains.

Is my transmission on the verge of failure? Or would this be considered within acceptable variation?

Please be gentle and explain to me like I am a not-so-bright second grader.

 

Our automatic transmissions have a lockup torque converter, which means that the only thing transmitting power from the engine to the transmission is ATF being spun really fast (sheared) between a plate connected to the crankshaft and one connected to the transmission input shaft (sorry that’s as 2nd grader as I can make it without breaking out my crayons). That sheared fluid creates a shit ton of heat, which then goes through a cooler in the bottom of your radiator to get cooled before returning to the transmission. At a certain pressure, the torque converter locks up, meaning that those two plates physically attach the engine to the transmission and it’s not relying on shearing the ATF to transmit power. That happens in overdrive (the 400 rpm drop you see on level ground at about 60mph or so), and it also happens in 3rd gear when you turn overdrive off with the button on the side of the shifter. Keeping the truck in 3rd gear will keep the torque converter in lockup mode at highway speed and will prevent the transmission from overheating.

The overdrive gear in our transmissions is also very small, even if the torque converter is in lockup in overdrive, the load reversals from normal trailer towing can do a lot of damage to the gearset. It’s highly recommended to only tow with the truck locked in 3rd gear. That will limit you to 60-65 mph without the engine screaming, but is much preferred to a transmission overhaul in the future.

Others will disagree with me, but you probably didn’t do too much damage by overheating the transmission once, and changing the fluid right away was exactly the right thing to do. I’ve done the same thing myself. Another thing to consider is installing a secondary transmission cooler either before or after the stock radiator cooler, to further bring temps down if you do a lot of towing.

 

Nope. Sounds normal.

Add an external cooler and you'll be okay. Keep an eye on it and all should be okay.

 

True story!
I learned this after asking @drr and @Digiratus about keeping temps down.
They both recommended installing a trans cooler (mine is after the radiator) and when going up a pass, flick the O/D button off to keep the trans from heating up.
Also picked up a ScanGuage II to monitor temps.

 

Agree with all of that.

Additional notes. The trans "cooler" in the bottom of the radiator is there more so to heat up the trans fluid is cold conditions than to cool the fluid in hot conditions.

Some people in warmer climates bypass that completely. It wouldn't be advisable in places that deal with freezing temps though. Cold trans fluid can actually do as much damage as overheated fluid.

In terms of the OD... worth mentioning that pre 1998 4 runner shifters... the button for the OD is an actual on/off switch. Meaning OD can stay off until you turn it back on even if you turn the truck off. Our OD switch is a momentary switch. It turns OD off until you switch it back on OR you turn off the truck.

 

I had it laying down, they all eventually leak or crack cus of the sun. This jerry can is made of metal and I hope will be my last can, I dont like it standing cus ik its hard on the airflow and clearance, but I knew that, I dont really go to drive thrus tbh and my truck clears my garage. I like it standing as it takes pressure off the seal and I know the gas jumps but makes me feel more comftorable like this. Now the location it had to be there because I dont need a swingaway rear bumper, dont wana make my single cab bigger, I live in LA, the less space the better. The can wont be on there all the time (im not that guy lol) just as an emergency for those longer trips. Jerry can came today.

 

looks like not a nato can. So probably won't be your last going off my experience anyways.

If you want a true last can grab a Scepter one next time. Expensive but worth it. What the military currently uses. And they won't care which direction you lay them.

 

Both my scepter cans leak.

 

That makes 3 scepter cans that leak... cause mine does too lol.

 

ah well lame. Both mine don't haha

 

Your seals are bad or the lids are cracked then. Not cheap to replace but if you have the right components they can be upside down and don’t leak.

 

Brand new seals and the lids not cracked.

 

You're going to need the extra gas for all that increased drag you created.

 

So...

Scepter cans don't leak
unless they leak
at which point, you need to replace a bunch of crap, so they don't leak

Until they leak again.

 

Sooo, what’s leaking then?

 

By the way... it's the Holidays and two of my 3 sons are home. (both of them used Scepter cans as part of their job, in the Army)

Lmfao... they BOTH agree... Scepter cans ALWAYS LEAK.

 

These are the best cans we’ve found.

VP Racing Fuels 3512 + 3044B 5 Gallon Square Red Racing Utility Jug w/ 14 Inch Deluxe Filler Hose https://www.amazon.com/dp/B00AVQC01U

 

Dude I just one of these for my extra long trips and they work so much better than Jerry cans.

 

Uhhh, yeah one of em definitely is gone or the threaded neck is cracked. These aren't even the good military Sceptre cans (just regular Sceptre home grade ones) and they survived a week in the desert on their sides exposed to the sun without leaking a drop or smelling even....