stupid trans temps

[06 H3]

Is that with or without the stat?

 

[06 H3]

https://www.etrailer.com/Transmission-Coolers/Hummer/H3/2006/D13503.html?vehicleid=20061229503

That is what I ordered I haven't hit 200 since I added the pusher fan when I did the v8 swap. Before the pusher fan with the I5 I usually would hit 205 on a 100+ degree day up steep freeway climbs at 65 with the ac blowing. I'm running a 160 stat

 

[digglesworth]

With the stat still. I thought I had a piece of tubing I could use to put in there for now but I must've thrown it away. I gotta find some tubing somewhere that I can flare on both ends and stick in there to replace the bypass valve...

Casey, yeah, no going back now... The answer is out there. I just gotta find it.

 

[digglesworth]

https://www.etrailer.com/Transmission-Coolers/Hummer/H3/2006/D13503.html?vehicleid=20061229503

That is what I ordered I haven't hit 200 since I added the pusher fan when I did the v8 swap. Before the pusher fan with the I5 I usually would hit 205 on a 100+ degree day up steep freeway climbs at 65 with the ac blowing. I'm running a 160 stat

That's the one I just took out. I mangled one of the barbs so I had to toss it. But that's also the one I hit 251 with. I was in the mud and really kicking the dog trying to get through a section. Lots of backing up and going forward...
Do you have any pics of how you mounted the pusher fan on top of that cooler?

 

[06 H3]

Hmmm then you probably have another issue because I never got that hot and neither has poncho and I believe he has the same one

 

[digglesworth]

I never had any issues til that day. Other than the cooler issues, I'm trying to figure out what could possibly cause a transmission to generate excess heat like that. Another setup I'm contemplating is probably complete overkill... It's along the lines of what amrg said. A 22"x8" plate/fin cooler mounted all the way across the condenser with either these 2 10" fans from these derale coolers I have or 2 8" pusher fans mounted on either side of the vertical support in the middle.

 

[digglesworth]

The fans would be similar to this but one on both sides and the cooler would go all the way across. The trucool coolers claim to have an internal bypass that works off viscosity of different fluid temps..

 

[4speedfunk]

Jeez...you guys are talking me out of the external tranny cooler mod. Cross contamination is a concern but, this sounds like another "if it ain't broke -don't fix it" story.
What's wrong with just an external cooler? (Dump the bypass/regulator/fan rig). It worked great for last 50 years on all sorts of tow vehicles & muscle cars.

 

[06 H3]

The only thing wrong with it and it's not even horribly wrong is that you can over cool a transmission. It takes a while for it to warm up, especially for guys in places where it gets cold. Obviously overcooling is not as bad as overheating but trans temp does have an ideal temp roughly 160-180 and without a thermostat u may never get there or it will take a half an hour to get to those temps.

For Diggle I don't know whats going on. He had the same exact cooler I had and he hit 251. I have never even gotten close to that. I put in my cooler and stat and its been **** free. I added fans when I did the v8 swap because I've heard of the issues people had with engine Temps with the v8

 

[digglesworth]

the only reason i opted for one with a fan is for wheeling where airflow from the outside is reduced. i guess im gonna drop the cash on that 160 stat, ditch this 180, go for the 13504 ( which is a 24 row vs 19 row on the 13503) and use the fan from this current cooler. im really thinking that this tube/fin cooler is just not up to the task.

 

[rsc]

Just a few thoughts and observations from a non-expert who didn't sleep in a Holiday Inn last night.
-The fan idea is a good one, especially for where you will need it- offroad at slow speeds.
-The tube/fin versus plate/fin argument may be null, if each cooler's GVWR recommendation is followed I don't think any one style is going to be superior...smaller or more efficient for a given size, sure, but not better.
-Going to a 160° thermostat is interesting, but once you hit whatever temp the thermostat opens at then any temps above that point will be controlled by the cooler and how hard you are pushing the transmission.
-Bypassing the thermostat to check restriction is a good idea.
-I think that while 180-200 is a good range to be in (and below 160 the torque converter will not lock up to generate heat? ), don't get hung up watching the gauges and get tunnel-vision on what may be a non-issue. The charts list maximum temps and lifetimes for temp ranges, but I believe that high transient temperatures are okay if they only last a short while (until you get above about 235 tho, the closer you get to fluid breakdown the shorter amount of time you should spike up to there).
-An auto transmission makes heat the harder you push it, either by slipping or increasing pressure to hold against slipping. If your transmission is old, you are going to see slightly higher temps than a new transmission. You may have to go to a Corvette servo to increase holding power. You may need a new kevlar band for better holding power and a shift kit. Your bands may be slipping slightly, you may have worn friction plates or warped steels that are still functional but then you will have to tear into the transmission to fix an internal problem causing higher temperatures. Is it worth the time and money to replace/rebuild your transmission now or keep driving it for another 30-50k miles until it needs a rebuild.

I don't know what is causing the high temperature issues and agree that keeping the temps in that 180-200° sweet spot is good but don't loose focus and forget that your transmission IS operating properly. Good luck with getting it sorted out, from my own engine temperature and transmission issues I know it can be frustrating.

 

[digglesworth]

Even dropping to a 160 stat, it should sit above 160. I'm pretty much figuring I'm gonna need a rebuild at some point in time. I'm just trying to prolong the life for now and get it to stop spiking so high above 200.

 

[poncho1965]

Hmmm then you probably have another issue because I never got that hot and neither has poncho and I believe he has the same one

Yes same one. I saw 240 once climbing a pass. I was letting the trans shift in auto, a lot of hunting back and forth. Now I hold it manually and it won't get over 210.

 

[digglesworth]

I had a guy at a local trans shop tell me not to leave the truck in D while out wheeling. This past weekend I kept it in 2 almost the whole time. The only time the trans heated up was when I had to turn around in a tight creek bed. Backed up a few feet, went forward a few feet, backed up, went forward, etc... By the time I got turned around, I was at 231.... Wtf...

 

[06 H3]

Before the transmission cooler I hit 240 everyday for the summer. I hit 256 a time or two. No one could understand why my transmission was perfectly fine after doing that for over 3 years. The second I put in a cooler it stopped hitting 240-250 and went to 200 in 100 degree weather and 160-180 normally. Something isn't right

 

[06 H3]

And was still fine to boot but rebuilt it after 140k for good measure

 

[digglesworth]

What im thinking Now is that it was just me beating the crap out of it that time that got it so hot... Now that I've went to an inferior cooler, it's not able to keep up with the cooling while driving. I'm gonna order that improvedracing 165 stat, the 13504 cooler and try that. The fluid is circulating cause I can get it to cool down by sitting. I just really don't think the cooler is shedding enough heat.