Mike_LS1

Should I use thread seal on the cooler line fittings when I screw them back into the case?

lrmneil

Nope just wipe them off and they will be fine.

01ssreda4

iTrader: (96)

Don't they have a washer on them? Stock new fittings have a dab of sealer in the threads possibly. Tapered threads seal with tape or liquid but these are straight threads that's why i suspect a washer and maybe the dab of liquid sealer.

1lejohn

iTrader: (9)

They are a NPT fitting (1/8" pipe) If its a 60E case. I always use a little teflon paste.

Vince B

iTrader: (1)

Teflon paste or a little anaerobic sealer is what I have always used. I prefer anaerobic to be honest.

carlsonauto

On a newer trans nothing is required, they are straight thread with a tapered seat at the base of the hex. As long as the seat in the case and the taper on the fitting is clean and undamaged they will seal up just fine. Older ones TH350/400 and 700R4 had either 1/4 npt or straight thread with a washer. Powerglides had 1/8 npt.... Pipe thread needs a sealer of your prefernce the rest dont..

01ssreda4

iTrader: (96)

They are NPS threads, not NPT.

01ssreda4

iTrader: (96)

stock fitting, thread sealer.

http://www.ebay.com/itm/TRANSMISSION...b2db83&vxp=mtr

Aftermarket fitting, washer.

http://www.ebay.com/itm/Speedflow-6A...cb35dd&vxp=mtr

1lejohn

iTrader: (9)

Then how did my AN to pipe fiitings work on my 60E case Hmmm? I lost the crappy steel and quick disconnects with the pain in the azz clips along time ago.

mrvedit

The threads/inch is the same, but the taper is different. Pipe has a taper, Straight does not. With your AN to Pipe fittings your probably knew not to really torque the aluminum fittings in, but when people do this with brass fittings they sometimes crack the case.
AN to straight fittings for the 4L60E are available on ebay.

My 2010 trans had different threads than my 2001; I suspect GM changed it around 2007. In my 2010 an AN-6 male-to-male with o-ring fits perfectly.

1lejohn

iTrader: (9)

good info. I knew they were national pipe.

01ssreda4

iTrader: (96)

Instead of being a smartass you simply could have searched NPS and NPT and you woulda seen why your incorrect fitting still was able to somewhat screw into the fitting hole.

Mike_LS1

I'm going to try some Loctite high temp thread seal.