6an lines/fittings for trans coolers

[L31MaxExpress]

No, the transmission case fittings are proprietary. One of them extends into the case past the threads. IIRC it may be different on the older 4L80Es, but mine is a '97 and these are what I used.

Russell 641390:
https://www.summitracing.com/parts/rus-641390

If the 4L80E lines are split apart with the return near the center of the transmission it uses the long fitting in the rear to return fluid into the center support. Use a short fitting and you will burn it up. If it is an earlier trans with the fittings nearly side by side like a TH350/700r4/4L60E it uses a shorter fitting.

 

[Erik the Awful]

That's good info to know. Does the requirement for a long fitting also apply to the earlier transmissions?

I was at a friend's house last night helping him part out a cab, and he has a later 4WD 4L80, and he'll need to know this. My 2WD 4L80 is the earlier version, and since I don't have the transmission cooler lines for Roscoe, I'd like to know if I need those fittings.

 

[df2x4]

That's good info to know. Does the requirement for a long fitting also apply to the earlier transmissions?

From the description of the Russell fittings I linked:

"Long rear fitting for most 1997 - 2008 4L80E and 4L85E transmissions. If using these fittings on earlier cases or other transmissions, you will have to trim off tube on the long fitting."

So my guess would be no, pre-'97 4L80Es shouldn't need the long fitting.

EDIT - Wasn't doing anything important so I checked Russell's catalog. They recommend the fittings I linked (part number 641390) for '97+ 4L80Es, and a different part number (640520) for pre-'97 4L80Es, 4L60Es, 700R4s and TH350/400s. So it looks like the '97+ 4L80Es are the only auto transmission in these trucks that require the one long fitting. Here's a link to part number 640520.

https://www.summitracing.com/parts/rus-640520

 

[L31MaxExpress]

From the description of the Russell fittings I linked:

"Long rear fitting for most 1997 - 2008 4L80E and 4L85E transmissions. If using these fittings on earlier cases or other transmissions, you will have to trim off tube on the long fitting."

So my guess would be no, pre-'97 4L80Es shouldn't need the long fitting.

EDIT - Wasn't doing anything important so I checked Russell's catalog. They recommend the fittings I linked (part number 641390) for '97+ 4L80Es, and a different part number (640520) for pre-'97 4L80Es, 4L60Es, 700R4s and TH350/400s. So it looks like the '97+ 4L80Es are the only auto transmission in these trucks that require the one long fitting. Here's a link to part number 640520.

https://www.summitracing.com/parts/rus-640520

FTW! To my knowledge the later 4L80E stands alone in the use of the fitting. The 97+ 4L80E also only needs the long fitting on the rear cooler fitting. The front fitting uses a normal fitting.