I plan on installing a cooler and have been told to place it so that the transmission fluid passes through the radiator first, then the cooler, before going back to the transmission.

Which transmission/radiator fitting is the return line - the upper or lower line?

Thanks

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1998 F-150 XLT, Ext Cab, 4.6/auto, 3.55 R, FlowMaster 40 Series w/ dual 3" chrome tips, CraneCams 8.5mm FireWire spark plug wires

 

I cannot remember which is which but if you follow this procedure, you will know:

PUT ON THE EMERGENCY BRAKE !

-Start your engine and put it in drive.

-MAKE SURE YOUR EMERGENCY BRAKE IS ON!!!!!

-Immediately go underneath the truck and feel both lines coming out of the tranny toward the radiator. The warmer one is the one that is going "out" to the radiator. The cooler one is "returning" from the stock cooler to the tranny.

 

The top is hot (from tranny). Bottom is to tranny.

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99, XL, SC, SB, auto, 4.6L, 255x70R16, 3.55LS, 2wd, Med Tor, Dk Grph, Raider LoRider Tonneau.
Deflecta-Shield Trailback Black Boards .Computer Code YBQ3
More to come!



http://home.att.net/~neilwood.pe/wsb...ome.html-.html

 

Logic says stuff runs down hill. The lower line shoulld be the return.

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97 F-150, 2WD, Reg Cab,Flareside,Dk Toreador Red, Windsor 4.6, Magnecor 8.5mm wires, Bosch Plat +4s, 3.55 LS, EGR Bug Deflector, Retrax Bed Cover, BedRug, XL Full Length Running Boards,EGR Fender Flares, Air Aid Kit, Gibson Single Out Cat Back, Superchips, TransGo Shift Kit, Hellwig Rear Sway Bar, Hellwig 2500# Overload Springs,Energy Suspension Polyurethane Front Sway Bar Bushings, 265 70 16 tires, Rancho RS9000 shocks,Expedition Center Console