Disconnect rad internal cooler?


May 24, 2001
I am trying to lower my operating temps, and was wondering if I disconnect the rads internal tranny cooler and run a LARGE auxiliary tranny cooler, will this lessen the load on the rad and still keep the tranny cool enough?

Because of size restrictions I cannot run a bigger rad, and in traffic my temps climb up around 200+ deg. (I’m already running an inline B&M cooler)


1972 Toyota Celica with an 87 TR Engine. 20 over, 10/10 crank, high vol.oil pump, ATR billet OD H20 pump pulley, 14” Permacool electric fan, RMI 25.
PTE 44 turbo, Big neck intercooler, Jay Jackson’s 62 mm Throttle body, ported and polished plenum with upper part of EGR tower removed and lower radiused, solid MAF pipe, K&N Filter, low imp. 52 # Siemens injectors, Adj. Fuel Reg, Hot wired Walbro GSS 340,
Type II coil pack and module, 8.5 Magnecor’s, Jay C’s 94, Red’s 100, Thrasher 92 chips, AC CR43’s, DirectScan, Caspers Knock gauge, Autometer 30/30 boost/vacuum gauge, Autometer tranny temp gauge.
200 4R tranny, B&M cooler, stock D5 converter, B&M Megashifter, Chopped Ford 9” @3:25 posi rear with a 300 ZX disk brake setup. Air bags, 85 Supra 57 mm piston 10” vented rotor front brake setup, Nissan 300 ZX 15/16 master cylinder, Dunlop SP 5000 205/50ZR 15’s, Hurst Roll control, Ford power steering rack, Bilstein Rally shocks rear, Tokico race struts front, heavy duty coils.
Hand made TH style DP, 3” exhaust split to 2 ½ “ dual Magnaflows.
I would...

Nope. will not help at all. (unless you got something real wrong and trans is running at 230 or better all the time which would not last long)

Test have been done and not a significant loss or gain noticed. I would let run thru both the thermal one ( radiator) and the air one (external) in that order. :D

Good Luck
Thanks Bruce
My B&M cooler is only the 24,000GVW unit, would jumping up to the 28,000 make much difference?
(Looking for every bit I can)
Would I experience too much of a pressure drop if I ran two in series ? (Since I already have one)
Is there such a thing as running the tranny too cool?

WE4, you said earlier to run thru rad cooler first then aux cooler. Well which line is out on the tranny and which is back from the rad cooler? Thanks

I will third it....

Opinions on what? ... As far as too big a line and pressure drop.....


No way
You would have to run 2 1/2 " pipe to make too big. Line smallest diameter should never be smaller than 5/16ths. As far as big, Make yourself happy . Go -10 if you like but man what expensive trans lines they will be!!! :D

Good luck