I apologize for some of these questions, I don't have a good manual (can't download the JTIS online -I'm on a Mac) and my car is in the shop still or I'd go look.
I did some searches and I found the car has a tranny cooler. Where exactly is it located? Is it physically in the radiator? If located within the radiator, why is that? What is it's normal operating temperature range? Will I run into problems with the temp being too low in the winter if I move it out of the radiator (assuming it's even in there.) I'm asking because I am having a problem overheating the Jag while on the track. Both the tranny and engine appear to be overheating and since I'll be doing a three day event at VIR in Virginia in August I figured now might be a good time to try some things...

 

The tranny cooler is separate from the radiator, mounted to the bottom of the radiator. It does have it's own thermostat built in.

You could probably go with a larger tranny cooler..... more rows......

 

I just installed a B&M tranny cooler in my Jeep ZJ. B&M uses the stacked plate design, rather than tube and fin or heat sink design and is much tougher and works better.

I was able to simply tap the fluid return line from the existing OEM cooler (in my case sandwiched between the rad and AC cooler) using the supplied fitting with the kit. Ran that hose to the B&M, then the output of the cooler to the OEM return line with another fitting. So I am running 2 coolers in sequence. It was important for me to keep the OEM one in the loop as it heats the fluid quickly in cold weather. I would recommend you do the same even though the location is different. If you find it shifts sluggish in the winter, you could always rig up a bypass system for the 2nd cooler or just disconnect it. I think you'll be fine though.

The cooler came with all the hardware and rubber line needed to do the job. It's very thin and you can find them small enough to use in the X type for sure. I ordered mine from Jegs, $60 shipped to my door. Took about an hour to install it, most of that just trying to figure out which line is which on my OEM system (my Jeep manual sucks).

As for performance - big change. I used to trip the overdrive lockout on warm days all the time once the tranny fluid hit 230 degrees (a safety feature on the Jeep tranny - locks out OD when tranny gets too hot). Running 33"s (not regeared) with headers = heat and strain on tranny. Just did a 200 mile round trip, with some woods and mud wheeling in between, A/C on the whole time, and it didn't trip the OD once.

I say give it a shot if you are concerned, it's really not very hard nor expensive. Good luck, let us know how it goes if you do it!!

 

That's an interesting idea, I hadn't thought of running a bypass line around the cooler. I might look into that. I can't wait to get my Jaguar back so I can actually take a physical look at everything!

 

Having owned plenty of awd Subarus over the years I've learned that the first thing one should do for any auto tranny is install a proper gauge so you know where you run. Having too cool or too warm of tranny fluid will hit your wallet quickly. Ideal is 140-170 but as was stated 230 can happen quickly in normal driving conditions and will definately shorten the life of you transmission if you don't know you cooked your fluid and change it shortly there after. Most good fluids have a flash point of around 210 degrees. Going above that is definately not a good thing to do. Only sure way to know if your driving habits or conditions cause issue for concern is for a gauge to be installed. Most cars have a tranny fault code for fluid but like with subaru they tend to come on way too late (299 degrees for a subie).

 

Hmmmm, wonder where would be a good spot to install it... Guess I could put it on the supply side to the tranny cooler. That is also a good idea...

 

In the pan is the ideal spot, as close as you can get the sender would be your next bext. The other key is that tranny fluid should be heated up to operating temp quickly which is why most coolers are in the radiator or close to it so it gets some radiant heating as the engine warms.

 

Good gawd, no light comes on in the Subie until 299 degrees! That's insane! At that point I would think it would just be insult to injury.....

Forgot to mention in my first post I flushed the Jeep tranny and replaced with Royal Purple ATF. 12 bucks a qt is expensive, but I beat on this thing mercilessly and need all the help I can get.

I agree with benebob, as close to the pan as possible for best accuracy. Even if you can get it reading in the general ballpark +/- 10 degrees or so will be very useful IMHO.

 

Yeah Chris at that point you better get your check book out. I suspect most cars are like that though. Your average idiot doesn't have a clue on tranny fluid and what the temp should be at. They no longer put gauges in cars and the average idiot would be quite pissy if their trans temp light came on during their commute to work on a regular basis. Wasn't a big deal when slushboxes were mechanical but with the electric controls they all get quite warm.

I won't use Royal Purple nor B&M or Redline simply because they don't let their fluid get independently verified. Mobil 1 Synth though is indie verified for its flash and fire points, is fully compatable with all other fluids (again indie verified) and is readily available. Not that the others aren't good but I want to know what temps are bad for it. No I'm not recommending Mobil 1 for Jags though either as I don't know if it is compatable or not. Me like manual boxes though I guess I should start looking for the wifes as I know it was changed 1 time about 25k ago.

 

Right on, I won't debate ya on fluids, Lord knows all that does is get everyone fired up.

I run Mobil 1 synth in my Saab tranny (factory rec) - good stuff.

Off topic, but when did you get the XJR, is that recent or did I just not notice it in your sig before?

 

Yeah people get funny about their fluids don't they.

Got the XJR a few weeks back. Here's some pics if you want a look.
http://s185.photobucket.com/albums/x203/benebob/XJR/

 

She looks pretty clean man! Nice choice! I'll be in the market myself pretty soon and the XJR is on my short list....

Sorry for the OT chknhwk - you get your ride back yet?

 

Very clean one owner 65k car with a complete service history (as in 34 hits on Car Fax- all maint except for 3 unscheduled visits and the annual registration entry. Even came with winter tires and wheels. Only real issue is the rear right door doesn't lock with the key fob and the rear seat was used to carry the tires to get mounted and left their markings on the seat. Looking for a replacement but will first try to redye it. I was originally looking for an 04-05 XJ8 but you can't get a hitch for it. Would have settled for an 03 8 but this popped up for $14k and should have a more solid tranny to boot.

Anyway, back to chknhwk's topic, give us some more symptoms and when it does it and when it doesn't.

 

No problem going off topic, a lot of things got covered before that.
Just picked it up and driving home now. I think I don't have overdrive anymore. What should my rpm be in fifth (OD) at 70mph?

 

I'm spinning 2500 rpm at 70, is that normal? It seems higher than what I'm used to... But then again I haven't driven it in a month.

 

That sounds about right to me chknhwk....

To test, manually shift using the J-gate and once you are in 4th at highway speed, slide it over to D and keep your eye on the tach. You should feel it shift too, the jatco isn't exactly smooth.

 

Oh it shifted when I went to 4th, it just still feels too high. I was wondering if I was getting low on fluid would it start spinning higher rpm to keep the torque converter spinning or whatever. I'm not real savvy on automatics, I prefer manuals.

So where is the tranny cooler located, anyway? I see the condenser covers the radiator completely and at the bottom theres a round cooler, what's that for? I didn't see a tranny cooler.