nexgen91

Hello,
Trying to get to the bottom of an issue I have been having with my Supercharged 02
Double Cab TRD V6. I put a B&M 70264 Aftermarket cooler on it with a 6.5 inch Spal push
fan it pushes 330 cfm. I also bypassed the stock cooler. Now on highway I am running
pretty cool, even around town in stop and go it does ok, never really gets much above
180 degrees, with the average being around 145-150 on highway (high 70s-mid 80s ambiant
temp) and 150-175 in stop and go driving (this is all without the fan running). But when
I go offroad, or up a grade/mountain range (climbing from 4,000 ft to around 8,000 feet
in about 16 miles) it really start to heat up, last weekend it got up to around 220
degrees while making the climb up the mountains, and yesterday while doing some wheeling
(some pretty good climbing as well) it got up to 208 degrees, I parked it and rode with
someone else as to not agrivate the situation. Both times I had the fan running and the
only time it would drop the temp was when I was sitting still or going downhill. Last
weekend when it I got it up to 220 degrees I pulled over to let it cool down, and got
out my infrared thermometer I checked the temp of the outlet pipe on the cooler and it
read around 150-160 degrees. I am using a scan gauge II for the temp readings, and I
have heard they read a little high (around 10-15 degrees), but even at 220 degrees (and
still would have been climbing had I not pulled over) that would mean it was around 205
-210 which seams high for my setup. Can someone please shed some light on this for me
and tell me if this is normal or is there something going on here. BTW: I have been
running Valvoline MaxLife Synthetic ATF since around the first of August.
Thanks

gdutch

Did you upgrade the valve body on your tranny after SCing it? The increased power of your engine is probably making the tranny slip more, which would cause it to run hotter. Just my .02.

Red3.slow

My truck is not supercharged, nor do I have a fan in front of my trans cooler. But I have the same set up and my temps run just about the same. They get a little hot off road, but I don't think that short periods of 220 are going to do much harm. Maybe think about switching to synthetic trans fluid.


Also who knows how accurate the scanguage is? I've always taken mine as a ball park number.

gdutch

If you're using a Scanguage for your transmission fluid temps, it's taking it from the bottom on the transmission pan before the fluid is sent. This is going to be the hottest temperature in the whole system.

nexgen91

Im running a synthetic fluid, Im going to change it at areound 20-25k miles (my truck will have 108,000-113000 miles on it then) just to be safe. It was suggested else where to run in low-range offroad, any input on that?

so when you see those charts with trans temp vs fluid life are they using this number or a reading from somewhere else?

Midget96

110% completely wrong. There is no sensor in the trans oil pan.

Scangauge gets its reading from a temp sensor in the output line of the trans. The sensor is located on the front of the trans, passenger side. Big and brass, 19mm, with 2 wires coming out of it.

This is the absolute hottest part of the system, where the fluid is leaving the trans and heading to the cooler.

I have an Autometer temp sensor in a remote oil filter mount about a foot from the output. I've seen temps of 250° on steep inclines when fully loaded. It's not going to kill your trans to do that every once in awhile, and I figure on a bad day I'm getting at least 30° out of the fluid with my big B&M cooler.

Your fluid will tell you when it's bad. Don't waste money and change it prematurely. Complete waste.

4-LO is a great way to essentially remove 75% of the heat in the trans when in mountainous terrain, as long as you don't need to go above 40 MPH. When I do that, temps struggle to get above 180°, but obviously the engine is working much harder.

Learn how to form paragraphs, too.

nexgen91

I dont get much over 15 mph in the mountains, so I will definatly try that next time I go out

J2F42C

the reason why I ask is I helped a buddy drain his AF343 tranny (Landcruiser) in August. Full fluid transfer. He ran the Maxlife synthetic for about three weeks before it started slipping on him in first. Weird. We changed it out with another full flush of Castrol Import ATF and no more slipping. Could his tranny be one foot in the grave? Maybe, I do not know.

I'm thinking that these Toyota trannys like somewhat highly modified friction ATFs. John from IPT on the tundrasolutions board said he has used the Lubegard black fluid, which is a highly friction modified ATF supplement, with good results. Turns out that the new Maxlife formula is so widely speced now that it includes Matic J for Nissan and Toyota' WS. Is it not now highly friction modified, even though it claims to be back specd for Dex II? Don't know. I have another friend running the old Maxlife formula in his T100 tranny with no problems after 30,000 miles.

Bottom line: keeping running the fluid, make sure the 70264 is kissing the condenser, and use 4-LO. If the fluid gives you trouble, change it. If not, use Amsoil, Redline, Eneos, or Castrol Import ATF for the next change.

nexgen91

Seams to be working fine for me, maybe the trans is on its way out and the high friction coefficient is helping it to not slip? I dunno, I dont have any slipping that I can tell.

nexgen91

Went out wheeling on Sunday, I kept it in 4lo most of the day (had the transmission is 1 or 2 depending on situatuion) Temps stayed around 150-160 on the Scan Gauge. I am wondering if I am doing more harm than good riding around in 4lo though. I mean most of the terrain really did not require it, I would have been ok with 4hi. Should I just put the TC in 4hi, and the trans in 1 or 2, or should I continue with what I did the other day since it kept the trans temps low. I would rather replace the transmission fluid than the transfer case or a diff because of putting to much stress on them. Thanks

Erich_870

I remember when guys were saying it was better to down shift your tranny to slow down than use your brakes (on the pavement) and then someone brought up the cost difference in replacing brakes and rebuilding a transmission. Sacrificing your tranny to save your transfer case makes just as much sense.

Frankly, if you're driving slowly in 4hi, you might as well be in 4 low. The forces and increased torque are only an issue from the transfer case output back to the diff, axles and tires. Your system is built for them and you're running your transmission within a better rpm range. The last thing you want to do is keep your torque converter right on the edge of slipping/engaging for long periods of time.

Erich

nexgen91

So I should just leave it in 4lo, then put it in 2hi on sharp turns etc. that would cause CV bind? what should I put the transmission in? I would like to do the 2lo mod, but I have a J stick TC and have yet to find a write up on how to do it.

quicksilvr

Make sure you turn your O/D off. Didn't see if that was mentioned.

I wouldn't use 4lo unless you actually need it....don't use it just to keep your tranny cool.

If your B&M 70264 is mounted correctly (tight to the condenser) and your lines are entering the cooler on the top or the side....I can't imagine it ever getting much hotter than 220. And 220 reading on your SGII is within a decent temp range for MaxLife ATF. Especially for relatively short periods of time. That 220 probably only equals a 185-190 degree ATF temp after the cooler. Which is pretty ok. ESPECIALLY if you change your fluid every 30K. It's transmissions running 100K mile/10 year old fluid that blow up with they get hot.

mt_goat

The highest I've seen my ATF was also running up a mountain trail, IIRC I was in 4WD high. I was racing up a steep dirt road that led up to a trail head (Imogene pass) from the Ouray side. I also got to about the 220 F point maybe higher and then slowed down. It cooled off as soon as I slowed down, my guess is the torque converter was unlocked and generating lots of heat.

quicksilvr

LOVE that part of Colorado. When I went to Lake City 2 weeks ago, my transmission got the hottest it's ever been, driving up the county road that eventually becomes Engineer pass.

pkt1213

iTrader: (1)

Buy a manual! :-D

nexgen91

Unfortunately that is not an option for my 02 double cab
Trust Me, that is what I would have chosen, I needed room for a family of four.

mt_goat

Yeah you guys have your problems too.

Erich_870

Each wheeling situation calls for different driving techniques to prolong your vehicles life, but if you are driving in 4hi, not going very fast and causing your torque converter to be on the verge of slipping for long stretches, it makes more sense to protect your transmission and shift into 4 low. Your engine and transmission will be operating in better rpm ranges.

The decision to shift into 2hi to get around an obstacle is something you'll have to evaluate for each given situation.

Erich