Trans oil cooler

I put a hitch on my 98 XJ. I want to install a transmission oil cooler. I picked up a B&M cooler with hardware. The fittings on the engine radiator are in a very tight location. I will need right angle 90 deg fittings for the radiator connections.
Do I really need to run the oil through the radiator and the oil cooler or bypass the radiator and run through the cooler only?

What are you going to be towing?

Class II hitch so it won't be much. Looking at a pop up camper and the occasional U-haul trailor. Otherwise stock XJ, but would like to lift it some day with larger tires. I got used to my F-150 that would pull a house off the foundation.

i have the same thing and i went throught the radiator then cooler. just did it a couple of weeks ago and drove it from cali to idaho and back (850 mi. ea.) last week without any problems, then agian i pulled out my A/C condenser while i was at it(converted A/C to onboard air) my tranny never overheated even fully loaded in the mountians(it used to bad). i'm running 32's with stock 3.55's for time being, BEWARE the fitting that came w/ my cooler were'nt right they were compression, while the jeep had 45* flare fittings. PM me if you have any questions.

I was wondering about the fittings.
I was planning on removing the factory fittings to check if what came with the cooler were the correct type & thread.
Hard to find 45 deg flared or furreled fittings. Do you know if they are SAE or metric?

if i remember right they were sae, i got mine at ace hardware, i just used brass plumbing fittings i had to use an adapter to go from the line side to a barbed fitting but it was'nt had to find them at all other than that, (i won't tell you how i learned they are not the right fittings or how i got the rad. side fitting not to leak after stripping the first three threads off, ooops i guess i told you) Psst. JB weld. YES I AM A REDNECK!!! LOL

Oh yes, JB Weld is good stuff. I used it to secure the blind bolts for the skid plates and hitch. I've used it on aircraft exhaust for temp repairs.
How did you get to the lower oil line? It's right below the coolant return hose and right up against the fender sheet metal? I was thinking I may have to drain the antifreeze and lift the radiator out a bit.

i hooked it in the middle of the upper line. that is the way b&m's instructions said to hook it up. that was the line that got hot first, while in drive with someone stepping on the brake.(i was kinda scared since my "someone" was my wife, it was her jeep and the whole front end was in pieces on the floor)

Can't you just cut into the return hose and use hose fittings for the entire installation? That's what I did....no hard fittings at all, and very simple. As far as still running it through the radiator cooler.......it sort of depends on how cold it is where you live. The radiator helps to warm up the tranny fluid when it's cold as well as cool it down when it's hot, so it's probably best to keep it if you live where it gets pretty cold.