Scroll down to the bottom for a TL;DR
I read a comment on another thread that brought up a good point. They said that for about 2% of the 4runner owners this automatic transmission was not designed for. I'm not saying this is true, but that's how it feels from my experience. Here me out, this might be a long post.
I've installed a B&M 70264 transmission cooler in series with my radiator with a pusher fan on the aux tranny cooler. In the last 15k miles I have replaced the following; radiator, thermostat for a cooler one because of the supercharger, new water pump, new fan clutch and new coolant. I read all of these threads and I can relate to their numbers. The problem is when you use your 4runner outside of what 98% of people use their 4runner for. On flat ground, stop and go traffic my tranny temps usually stick around 165-190 depending on temperature outside. Even when I'm going up short inclines there are times where it usually sticks around 180-195 degrees, but once you crest it levels out and starts going down. This changes as the duration of the incline goes longer.
My problem is when Im towing(around 3000lb) really steep inclines for long periods of time or when off roading on really steep inclines going really slow for long periods of time. Yes, O/D is turned off. The button is not clicked in. Flat ground towing I stay round 180 all day long. Even short inclines it won't move a lot.
my last trip with minimal camping gear and no trailer, air temperatures are in the 90's, all day long on relatively flat ground with the occasion of hill that you need to crest, transmission temperatures barely move from 165-180. As soon as I hit a longer climb i start to see 200*+ but level out fairly quickly once I crest. Now when I get into the mountains and I'm off roading, very steep incline, going very slow(2-3mph) and it's for longer periods of time(15-20+ minutes), the temperature went to 250* capping out my gauge. At this point I pulled off on the next flat spot and waited 5-10 minutes and let it come down 30* before going again. This would give me another 5-7 minutes before I would hit 250 again, by the next time I was near the top. My pusher fan doesn't do squat for cooling under these situations and it feels like the aux cooler only really slows the heat process, but with enough time the temp will keep rising if you continue with the same conditions. Short to medium steep inclines on rolling hills, where you level out for a short period of time, temperatures usually hang around 180-195 while going fairly slow(10-15mph).
It feels like this transmission generates so much heat during the long periods of time either slow crawling or under heavy load while towing. I'm running into a few people with similar stories. Am I part of the 2% where this tranny cooling fails to deliver? Around town, stop and go traffic, short to medium duration inclines even in 100* ambient temperature it does just fine. It's like the cooling system doesn't effective keep the transmission temperature down when it's under load for a long period of time. Maybe thats normal and they didn't design to for those conditions.
I'm contemplating whether I should put another aux cooler in series with everything else. How will this affect the cooling system for the engine if I have two large transmission coolers in front of the condenser? Will this finally solve my issue? Anyone running two aux coolers up front?
TL;DR
Under unique situations I've hit 250* transmission temperatures with an in series external transmission cooler with pusher fan, should I consider adding a second one and will that affect engine cooling?
I read a comment on another thread that brought up a good point. They said that for about 2% of the 4runner owners this automatic transmission was not designed for. I'm not saying this is true, but that's how it feels from my experience. Here me out, this might be a long post.
I've installed a B&M 70264 transmission cooler in series with my radiator with a pusher fan on the aux tranny cooler. In the last 15k miles I have replaced the following; radiator, thermostat for a cooler one because of the supercharger, new water pump, new fan clutch and new coolant. I read all of these threads and I can relate to their numbers. The problem is when you use your 4runner outside of what 98% of people use their 4runner for. On flat ground, stop and go traffic my tranny temps usually stick around 165-190 depending on temperature outside. Even when I'm going up short inclines there are times where it usually sticks around 180-195 degrees, but once you crest it levels out and starts going down. This changes as the duration of the incline goes longer.
My problem is when Im towing(around 3000lb) really steep inclines for long periods of time or when off roading on really steep inclines going really slow for long periods of time. Yes, O/D is turned off. The button is not clicked in. Flat ground towing I stay round 180 all day long. Even short inclines it won't move a lot.
my last trip with minimal camping gear and no trailer, air temperatures are in the 90's, all day long on relatively flat ground with the occasion of hill that you need to crest, transmission temperatures barely move from 165-180. As soon as I hit a longer climb i start to see 200*+ but level out fairly quickly once I crest. Now when I get into the mountains and I'm off roading, very steep incline, going very slow(2-3mph) and it's for longer periods of time(15-20+ minutes), the temperature went to 250* capping out my gauge. At this point I pulled off on the next flat spot and waited 5-10 minutes and let it come down 30* before going again. This would give me another 5-7 minutes before I would hit 250 again, by the next time I was near the top. My pusher fan doesn't do squat for cooling under these situations and it feels like the aux cooler only really slows the heat process, but with enough time the temp will keep rising if you continue with the same conditions. Short to medium steep inclines on rolling hills, where you level out for a short period of time, temperatures usually hang around 180-195 while going fairly slow(10-15mph).
It feels like this transmission generates so much heat during the long periods of time either slow crawling or under heavy load while towing. I'm running into a few people with similar stories. Am I part of the 2% where this tranny cooling fails to deliver? Around town, stop and go traffic, short to medium duration inclines even in 100* ambient temperature it does just fine. It's like the cooling system doesn't effective keep the transmission temperature down when it's under load for a long period of time. Maybe thats normal and they didn't design to for those conditions.
I'm contemplating whether I should put another aux cooler in series with everything else. How will this affect the cooling system for the engine if I have two large transmission coolers in front of the condenser? Will this finally solve my issue? Anyone running two aux coolers up front?
TL;DR
Under unique situations I've hit 250* transmission temperatures with an in series external transmission cooler with pusher fan, should I consider adding a second one and will that affect engine cooling?
