Trans cooler

Chris · January 20, 2012

where in ca are you at?

wavery · January 20, 2012

where in ca are you at?

Beverly Hills......... I manage an apt building here.

txab · January 20, 2012

If the lines are pointed down, the cooler will drain back into the trans when the engine is off. You don't want that.

Guess you better point that out to GM since that's the way the factory coolers are mounted

Chris · January 20, 2012

factory coolers are mounted lines down?

wavery · January 20, 2012

If the lines are pointed down, the cooler will drain back into the trans when the engine is off. You don't want that.

Guess you better point that out to GM since that's the way the factory coolers are mounted

If that's the case (I haven't seen one) there must be a one-way valve somewhere (maybe in the trans..... .

I still wouldn't mount it hoses down, but that's just me..... That was the way I was taught a hundred years ago and I've always done it that way.

txab · January 20, 2012

On an 800 series with this setup the top line on the radiator cooler is the output or return line. It flows to the aux. cooler then returns to the trans. Bottom line on the radiator is FROM the trans. You can find numerous flushing procedures that show removing the top line at the radiator and attaching a hose to the radiator to flush fluid. As I stated earlier, best to check flow direction yourself to be sure.

http://www.gmfullsiz...ad.php?t=179148

And here's a pic of the 800 aux cooler setup. I believe the 900 series is the same.

One method of mounting......

wavery · January 20, 2012

Wow!!!! The factory cooler is small..........

CKNSLS · January 20, 2012

I have my doubts how effective that small of a cooler can be. I have the one pictured (800 aux) on my 2011-5.3 w/the tow package. I was looking for a "pusher fan" because I have exceeded transmission temps of over 200 degrees during the summer. The thing is so small I can't even find a fan for it. I have found a manufacturer that makes a deep pan w/cooling fins for the six-speed that gives you an extra two quarts of capacity.

I think I will probably go that route with Amsoil fluid. That should cool it down quite a bit.

Chris · January 20, 2012

im going to do the deep pan as well for my 4 speed and run the cooler. upgrade your cooler the b&m one i got was $57 on amazon

wavery · January 20, 2012

I have my doubts how effective that small of a cooler can be. I have the one pictured (800 aux) on my 2011-5.3 w/the tow package. I was looking for a "pusher fan" because I have exceeded transmission temps of over 200 degrees during the summer. The thing is so small I can't even find a fan for it. I have found a manufacturer that makes a deep pan w/cooling fins for the six-speed that gives you an extra two quarts of capacity.

I think I will probably go that route with Amsoil fluid. That should cool it down quite a bit.

My truck is only used for towing my 4K# trailer and the truck loaded to max payload rating. So all examples are with that criteria.

The pusher fan makes a big difference in traffic or if you get slowed climbing a steep grade. If you can maintain 50+MPH, the natural air-flow is about the same as the pusher fan.

The only time that I have come close to 200* was sitting in traffic (before I installed the pusher fan) and climbing the Grape Vine (long steep grade in SoCal) in 115* weather with the A/C running. I have never seen trans temps over 200* even with engine temps approaching 215*. Normal running temp on my trans is ~165*.

I use Synthetic ATF, which I highly recommend. Synthetic ATF is a coolant. Normal, petroleum based ATF (and/or motor oil) is more of an insulator and does not like to give up the heat as easily.

I was considering the deep pan as well but it only adds 2 qts to the already 9 qt capacity. I just haven't seen the need for it and @ $8 a qt for sythetic ATF........ it just adds additional cost with little benefit. If I were towing an 8K# trailer, I would do it but I wouldn't even consider towing an 8K# trailer with a 1/2T PU.

CKNSLS · January 20, 2012

I have my doubts how effective that small of a cooler can be. I have the one pictured (800 aux) on my 2011-5.3 w/the tow package. I was looking for a "pusher fan" because I have exceeded transmission temps of over 200 degrees during the summer. The thing is so small I can't even find a fan for it. I have found a manufacturer that makes a deep pan w/cooling fins for the six-speed that gives you an extra two quarts of capacity.

I think I will probably go that route with Amsoil fluid. That should cool it down quite a bit.

My truck is only used for towing my 4K# trailer and the truck loaded to max payload rating. So all examples are with that criteria.

The pusher fan makes a big difference in traffic or if you get slowed climbing a steep grade. If you can maintain 50+MPH, the natural air-flow is about the same as the pusher fan.

The only time that I have come close to 200* was sitting in traffic (before I installed the pusher fan) and climbing the Grape Vine (long steep grade in SoCal) in 115* weather with the A/C running. I have never seen trans temps over 200* even with engine temps approaching 215*. Normal running temp on my trans is ~165*.

I use Synthetic ATF, which I highly recommend. Synthetic ATF is a coolant. Normal, petroleum based ATF (and/or motor oil) is more of an insulator and does not like to give up the heat as easily.

I was considering the deep pan as well but it only adds 2 qts to the already 9 qt capacity. I just haven't seen the need for it and @ $8 a qt for sythetic ATF........ it just adds additional cost with little benefit. If I were towing an 8K# trailer, I would do it but I wouldn't even consider towing an 8K# trailer with a 1/2T PU.

Let's not forget that the 2011-5.3-6 speeds are supposed to have sythetic ATF in them I beleive. The truck is rated at 9,500 pounds and my trailer does not exceed 5,500 pounds. I really don't want to cut the factory lines, hence I am hesitant to go with a larger cooler, although I may go that route if I continue to exceed 200 degrees. My truck has 10,000 miles on it. As far as the deep pan, two more quarts gives you an additional 22% per-cent of fluid. I have heard that Amsoil fuel efficient tranmission fluid runs a lot cooler.

wavery · January 20, 2012

Let's not forget that the 2011-5.3-6 speeds are supposed to have sythetic ATF in them I beleive. The truck is rated at 9,500 pounds and my trailer does not exceed 5,500 pounds. I really don't want to cut the factory lines, hence I am hesitant to go with a larger cooler, although I may go that route if I continue to exceed 200 degrees. My truck has 10,000 miles on it. As far as the deep pan, two more quarts gives you an additional 22% per-cent of fluid. I have heard that Amsoil fuel efficient tranmission fluid runs a lot cooler.

CKNSLS,

You may want to start a new thread on your vehicle....... The OP has a 2004 and does not have synthetic..... these posts are directed at the OP.

That being said........ you would not have to cut lines on your vehicle. The OP made a a very common mistake by doing that.

CKNSLS · January 20, 2012

Let's not forget that the 2011-5.3-6 speeds are supposed to have sythetic ATF in them I beleive. The truck is rated at 9,500 pounds and my trailer does not exceed 5,500 pounds. I really don't want to cut the factory lines, hence I am hesitant to go with a larger cooler, although I may go that route if I continue to exceed 200 degrees. My truck has 10,000 miles on it. As far as the deep pan, two more quarts gives you an additional 22% per-cent of fluid. I have heard that Amsoil fuel efficient tranmission fluid runs a lot cooler.

CKNSLS,

You may want to start a new thread on your vehicle....... The OP has a 2004 and does not have synthetic..... these posts are directed at the OP.

That being said........ you would not have to cut lines on your vehicle. The OP made a a very common mistake by doing that.

OK-didn't mean to hijack the thread or anything!

wavery · January 20, 2012

OK-didn't mean to hijack the thread or anything!

You didn't really hijack it. It was just starting to get a little bit confusing and you would probably get more help if you had a thread of your own.

marpel · January 21, 2012

Sorry for directing this thread a bit away from your trans cooler issues, but I couldn't help noticing your comment about towing a 9000 lb trailer (loaded/unloaded?).

I just traded in my 4.8L 1500 ext cab sierra for a 6.2L cause it wouldn't tow my 3100 lb trailer (contents and passengers adds another 1000 lbs??), without struggling, especially through the mountains. Unless I am mistaken, there is no model 4.8L that is rated to tow over 7200 lbs. Even with a cooler, should you be towing that weight?? Heck with towing, how about stopping? Or did I read wrong? If I did, I apologize.