Originally Posted by Manlaan
Well, I went ahead and did this.
Really not hard at all. The biggest pain is dealing with the hoses. I ended up just adding a connector between the existing hose and the new one. Its just too much trouble to get to the metal line from the trans with the cross member in the way. I did have to go back and pick up an additional hose since the one in the box was just too short for both connections. With the two hoses, I was able to run from the return line in the radiator to the new cooler, then back to the return line in the trans, so the fluid first goes through the radiator, to the cooler, then back to the trans. (thats how they recommended it anyway)
I ended up with one larger than the 678, the 679 (they were out of the 678 and I didn't want to wait) and mounted it directly in front of the condenser. There's one ac line that goes between the bracket and the condenser that had to be moved in front of the bracket, but not a big deal as the bracket comes off fairly easy with a few screws.
As far as my 15 mile test drive went...
Max temp before: 180s. Low about 170
Max temp after: 159. Low seemed to be about 145 after everything got nice and warmed up (which seemed to take quite a while). Max temp seemed very hard to reach. I'd say a more avg high would be about 155. In driveway temp is hard pressed to get to 130s. (Is too cool such a thing?)
Water temp wasn't affected at all, that I could tell. Of course I couldn't tell if the fan was working more or not.
Just for completeness, I do have the green fan clutch (but dont have tow package - after market class 3 hitch with Hopkins 4 prong harness. No clue why I have the green fan, but not complaining.)
Oh, and a pic before I cleaned things up and put it back together.
Nice. I've also seen others just add a connector to the stock hoses for ease of installation. I also know what you mean about being a bit hard to get to the hard lines as they're sitting in between the cross member & tranny making them hard to get to.
I choose to run my my lines directly to the hard lines & ditched the stock hoses. Using some long angled needle nose they were pretty easy to take off. I used the hose that came with the hayden to connect to the hard line going back to the tranny since the OD was close to the stock hose & use the stock clamp since using a worm drive clamp would be pretty tough to tighten in there.
The additional hose that you got, did you make sure to use oil transmission cooler hose? If not be sure to check on your hoses as fuel line or heater hose (for coolant) will not last long.
Others have gone with the larger 679 too. I choose not to since I don't tow very often. If you dont tow often & have cold climate those temps you reported just may be too cold. I've heard that AT fluid needs to be around 170 to perform as intended. It's ran into the radiator to help bring temps up to operating temperature quicker if in cold climates & to obviously cool the oil when it gets too hot.
Hayden says to install it after the stock heat exchanger & so does the TRD cooler. There's a big debate over this. Those with the larger cooler like yours run the cooler before the stock heat exchanger to prevent AT oil temps from getting too cold & to keep the temps consistent. Since I went with the size that's the same as the TRD cooler I choose to run it after the stock heat exchanger.
I wouldn't worry unless you rarely tow & don't have cold temps in the winter. If you do just keep an eye on the temps & run the cooler before the stock heat exchanger if your temps are too cold.
Nice that you lucked out on the green fan clutch too. The oil cooler shouldn't affect the clucth fan at much if at all since it mechanical. Only electric fans rely on a temp sensor to kick on. A fan clutch engages with ambient temps around the fan clutch. Proabaly not a big difference in heat radiating on the radiator to affect the fan clutch.
Originally Posted by Manlaan
Suggestions for clamps? This type seems to hold better than the factory ones, which are the squeeze type, which seemed to hold fine for the pressures involved, but I'm not really one to cheap out on something like this either.
I wouldn't worry, you will be fine with common worm drive clamps as long as they're not cheap crap. When I question the quality of a worm drive clamp I would clamp it over a hard rod & screw it tight. If it's cheap crap the clamp/cover holds the worm screw will bend & tend to come loose. If a clamp does this I toss it in the trash.
Originally Posted by Digiratus
i'm curious about what is holding the heat exchanger in place. Is it mounted to the radiator or does it have mounting brackets that aren't seen in the pic?
It is interesting that the upper temp in the FSM is 176. I am seeing 181-183 regularly in normal street driving. Haven't had the SG long enough to test on the trail.
I'm not surprised the water temps are unaffected. Likely the t-stat maintains temps by opening and closing, If you take away a little heat, it just closes up a bit to maintain its 196-202 range (orange fan clutch).
Since the FSM has a "lower" temp, it is possible that the fluid might need to have some sort of minimum. Not really sure. Did I read somewhere that you experienced +250* tranny temps on the trail this summer? The true test of any tranny cooler will be on those 100* days, in 4lo for that long hill.
The stock heat exchanger is just a tube that's ran through the lower section of the radiator. It normally soldered in place when the radiator is manufactured but I think ours has fittings to keep it in place since the end caps are composite.
I have a lower temp thermostat & so far my coolant temp has not gone over 175 in 90 deg days. It's normally stays between 168-172. But I haven't had the UG for that long so not sure how hot it will get in 100+ summer days & mashing on the trails.