tranny cooler re-do...

[poleclimber63]

After installing my tranny cooler back in May and posting it, I had a response from a fellow forum member warning me that my mounting choice maybe a problem, as it was mounted 3-4 inches from the A/C condenser and that at low/no speed I may not have sufficient air flow through the cooler to be effective. I checked this and at idle, I had very little air flow. I installed a tranny temp gauge to record data (on another forum member’s advice). In fact, while not towing, temp was recorded at a max. nearly 195, on a hot day. However, while towing, temp reached 210-- all recordings were at low speed. At a reasonable speed, temp dropped to just under 180, and towing below 195. With these numbers, I saw 2 choices: 1) install an additional fan, 2) re-mount the cooler. I looked at clearances and determined I would have to re-do the mounting, to get the fan in. Therefore, I decided to re-mount the cooler against the A/C condenser, positioned, in the centre. I had to modify the grille/ latch strength member to get the cooler in, but it worked. I apologize I have no pics (was in a hurry to get it in the shop for a complete flush) to show at this time, however, next time I remove the grill, I'll take some. I really didn't like sticking the straps through the condenser/rad but it seems, that due to my gentleness (tightened straps only enough to hold the cooler in place), I only lost a few small fins... we shall see the result in time... I re-checked the air flow on completion, and was pleasantly satisfied to observe a sizable air flow in comparison--- that few inches made a HUGE difference--- air like fluid, will take the path of least resistance--- in the case of my original mounting location, the air simply bypassed the cooler, unless I was moving!!

 

[95bb2]

I just mounted mine on the condenser, I have a scan gauge and have been monotoring the temperatures i live in Florida and just driving around in reg traffic I see mid 160-185 being the max, while being on the highway 140-160

 

[nissanh]

Hi, I installed a cooler directly facing the lower valence opening. Plenty of air when moving. I also use the radiator cooling. So at low speeds, It still get cooled from the lower radiator tank. At high speeds the auxiliary cooler do its job. Did 75 MPH on 95 F day. Temperature is at 111 F! pretty low. Can touch the sending oil line.Hope this is not too cold.

Don't forget to put a mesh to cover the Aux cooler from the road derbies.

 

[poleclimber63]

pics of my re-do...

I took my truck out for a drive on the highway as well as some stop n' go traffic (air temp 95) and the indicated temp rose to just under 150 and just above 150 at idle. Next time I tow the boat to the lake I'll post the results. I've included pics of the re-install:

 

[poleclimber63]

By the way, I've bypassed the rad cooler and capped it.

 

[Drcoffee]

You did a great job on the install and mounting the cooler against the radiator is the best way to mount it. It uses the engine's cooling fan to draw air across the cooler.

As far as longevity goes, consider using a plate style cooler like the B&M 70264. The fin and tube style you used is vunerable to damage from road debri like stones and sloppy mechanics because the aluminum cooling tubes are thin walled and not protected at all.

 

[poleclimber63]

Good run...

We just drove from Cache Creek to Whistler BC over a very demanding and high altitude road. Lots of hairpins and steep climbs with 90 temp... On the steepest longest hill near the summit the tranny temp. Reached 210. I'm not entirely pleased. I only had 4 passengers and a moderate load. I wasn't towing. I believe, I may require more cooling capacity... I'm running synthetic fluid which stands up higher temps, however, I want to keep the tranny temp down as much as possible. Does anyone who 4x4s in AZ or UT etc. Have any comments on max acceptable temps? I believe, the warning light sensor is 260 degrees...

 

[LittleCaesar]

I think the temp light comes on at 300F, which by then your tranny is toast.

Since you have your cooler in the optimal location, I would take a hard look at your fan clutch if it is original. Regardless of the cooler's location, if the fan is not moving enough air (I do not know the optimum CFMs either), then the ATF will not be cooled down quickly enough. OEM would be the way to go for a replacement.

 

[Drcoffee]

We just drove from Cache Creek to Whistler BC over a very demanding and high altitude road. Lots of hairpins and steep climbs with 90 temp... On the steepest longest hill near the summit the tranny temp. Reached 210. I'm not entirely pleased. I only had 4 passengers and a moderate load. I wasn't towing. I believe, I may require more cooling capacity... I'm running synthetic fluid which stands up higher temps, however, I want to keep the tranny temp down as much as possible. Does anyone who 4x4s in AZ or UT etc. Have any comments on max acceptable temps? I believe, the warning light sensor is 260 degrees...

If you plan to bypass the radiator, you'll need two coolers, not just one. Don't go cheap either. Get a B&M that's 1 1/2" thick. Because of the limited space get two 70264 coolers and put them in series.

This has always been my concern and argument. People read threads by the likes of tbst on bypassing the radiator on some irrational fear of the pink milkshake and neglect to do the bypass correctly. Your transmission is an expensive piece of hardware. If you want to play engineer, go all the way and do it right. Otherwise you will end up breaking stuff.

Look at that asthmatic little cooler you have on the front of your truck. Do you really think its the best solution when climbing a mountain? Hopefully if I make an example of this here, others will stumble across this thread and think twice before doing this mod.

You have a fin and tube cooler. It's not the best solution. Dump it and get a thicker plate style cooler. Why? Heat transfer, durability and designed to internally bypass the ATF flow until the fluid heats up. You may have to keep tweaking the setup until you get it right. Or reconnect the radiator(only if the radiator is newer) and use one cooler and be done with it.

There are some guys here who have done it right with multiple coolers and fans and meters and yada yada but these guys are fanatics and keep an eye on the data stream. Most of us are fire and forget people. Just enough knowledge to be dangerous.

So now I'm going to sit back and get berated for being a jerk but good grief, this topic has been more than discussed before. If you want to read some fun posts, try this thread.

-transmission cooler to bypass the radiator or not to bypass

 

[Drcoffee]

PC63,

Have you done a comparison of temps while towing, with and without the radiator connected to the new cooler? I was hoping for some follow up data before the summer ended.

 

[poleclimber63]

Sorry

Spent most of August on the road (vacation) with the family, so didn't tow much. When towing locally, I never saw the gauge rise above 190, even towing up a steep hill. One conclusion I've made is: that a Supercharger mod will be on my list for next spring, as the 3.4L needs a little more, when my 3000lbs sportboat is following behind, but alas, that is a topic for another thread!

I spent last week de-rusting/treating the front and rear bumpers and frame structures-- see my pics...

Unfortunately I had to put the boat to bed for the winter, this week, as I won't get a chance to take it out again before the frost (late Sept- early Oct) but I will say, I do plan to either replace the rad or install a 2nd cooler with a thermostatically controlled fan, next spring. I have all the parts required, except the cooler. I do see the wisdom in the rad replacement, as it acts 2 ways: brings the transmission up to a normal operating temp. and cools it when under load.
Thanks for the interest!