XJ Transmission Oil Coolers

[kyphonii]

Originally Posted by Rodgebone

did a lengthy drive in rush hour traffic today (ambient @ 28*C). crept along for over 30 minutes at under 30kph and saw temps fluctuate between 190 and 220*F! cant wait for those fans to show up!

I've been following this transmission temp thread and I've go a few questions.
I've had my xj 96 for about 6 weeks and I've have been watching my transmission temp, my transmission will get to 100 c with several hours of town driving, the engine gets to 100c but stays there. I've not been able to take it in to sand or lots of low range driving to date. The vehicle is stock in all regards concerning the cooling system.
Im thinking of leaving the radiator and fans as they are as it appears the thermostat is working. The temp bounces around 95 to 100.
What I have planned to try is a additional radiator 250x550 mounted in the winch recess of the bullbar with 2 thermos. The radiator is not in the air flow of the main radiator. I'll take the flow of the heater circuit. Has this been done by any one.

[Rodgebone]

not sure what kind of cooler you are talking about - engine or tranny?

[kyphonii]

Originally Posted by Rodgebone

not sure what kind of cooler you are talking about - engine or tranny?

Well at this point I'm looking at additional cooling area and capacity for the engine with the transmission cooled by the main radiator and the standard transmission cooler. The main radiator will have a significant reduction in heat that it will have to dissipate and should handle the transmission as well as stabilised the temps around the engine and transmission, I don't have a problem with 95 to 100 as long as I have surplus capacity to handle the spikes in temp.
I will also vent the engine bay as a lot of heat is radiated off the engine and transmission.
If the transmission takes to much heat to the radiator then I'll up the transmission cooler to large but will locate it else, where not in front of the main radiator.The transmission cooler should be before the radiator.
I would consider a engine oil cooler but over the years I have found them to be a small effect in over heating but It will be mounted else were as well.
The main radiators are sacred to me, even the air con is trespassing on sacred air flow

We did this years ago with V8's . Additional cooling area is more effective than looking for extra efficiency from the existing radiators systems.

[kyphonii]

I took my daughter for a driving lesson in the jeep (L Plates), she refers to the jeep as her jeep know, I let her take me up the only hills around here so as to heat the transmission up a bit. the transmission was in low gears must of the time and not locked up at any time, 34 degree day and air-con on. The engine temp doesn't move so it's handling the heat fine, the needle sits on 100 but my infra-red thermometer says 90-95 so the gauge is out a bit. The transmission temp went to 110 on the VDO gauge but what interested me is that the transmission temp moved around a bit 95-110 but didn't effect the engine temp. As we descended the hills the transmission took till the bottom to return to 90 thats about 20 min of no load. Would I be right in thinking that the transmission oil traveling through the radiator has little effect on the engine temp and as a result the radiator doesn't have the capacity to absorb the heat from the transmission.
It wasn't a very big workout for the transmission so I'm thinking that a big cooler is needed before I give it a hard time. Is the heat exchanger in the radiator even worth the effort.

[Rodgebone]

most of the time (under normal operating temps for the engine and tranny) the engine coolant is warmer than the tranny fluid and heat always travels from hot to cold so i doubt the radiator is doing anything to cool the tranny. as well, the heat exchanger in the rad is only there to warm up the tranny on very very cold starts (which rarely happens in Oz). so basically the heat exchanger is worthless here and only makes the tranny fluid warmer. just my two cents.

[ChrisXJ]

X2 Rodge. I reckon the same

[tazwegion]

That's some transmission cooler you got yourself there Rodge makes me wonder if my DC V8 oil cooler is going to be sufficient (in tandem with heat exchanger in the radiator), perhaps active cooling assistance may be necessary?