I want to get away from the stock transmission lines on my Demon. Does anyone know what size fitting goes in the 727? Or if I can just screw an AN fitting on to the stock fittings?

I use -6 line.... pipe to AN fitting on trans. Straight on the front, 45 degree on rear.

Thanks J-body

By chance know the pipe side size?

They may be 1/4 NPT, do you have a 1/4 NPT tap to see with ?

Pretty sure they are 1/8" NPT. I use -6 AN also. Many will say to use the more expensive PTFE lined AN hose, but it isn't needed. It is better quality, but not required for trans lines.

yup. 1/8"NPT. the A518 "may" have gone to 1/4"NPT, as the line size increased to 3/8" od. tube from 5/16".

Yes, use 3/8" line, don't want to slow down the cooling cycle.
Put a B&M filter in the line somewhere before the cooler that you can service it to keep it clean (don't accumulate trash inside the cooler) and detect friction material loss.

Thanks gentlemen.

Polyspheric thanks for the tip I’ll look and see what I can find.

Buy a metallic cooler line filter housing - trans fluid ignites pretty easy if the plastic filter body melts or fractures. Magnefine Boss had the best filter out there - used a magnet on the inlet side plus a good filter media with bypass inside. Screwed together so you could take the filter out for examination.

We tested it and it took over 4 grams of clutch debris to block the filter media. That means you aren't likely to go far when you fail that much friction material. And with the magnet it continues to collect any ferrous material. The aluminum gets trapped in the filter media.

The FWD cars used 5/16" line, most RWD cars in the day used 3/8" and so did most gas engine trucks, and we went to 1/2" lines on the 47/48 diesel for extra cooling of the lube.

Here is an image of one of those magnefine filters. Nothing wrong with the B & M except you have to cut then dispose of it each time you want to take a look. Plus it takes up a bunch of room. Flow is not an issue with the smaller filter but if you use one of these on a 1/2" line setup use the bug filter fittings. We did exhaustive test on these filters. And you Chrysler dealer techs will remember seeing these filters in our Reman trans kits. Those that used them ended the multiple trans failures when you followed the directions.

-6 Teflon. Yes, it's worth the little extra money. We've used some of the cooler with fan packages back under the car to eliminate some of the spaghetti at the front of the car. Has worked OK.

-6 teflon/PTFE hose.

I used some from this place. The only issue I had was the ends were not the standard sizes so the fancy AN wrenches didn't fit. Chinese stuff I'm sure and tolerances. Worked OK after that was figured out.

http://anfittingsdirect.com/

Since my car is outside and it’s snowed about 5” this AM does anyone have the ability to measure from the trans to in front of the radiator? I need to know line length so I can order this stuff. I’m using aeroquip startlite line and fittings.

All the early(1957 to 1974) Mopar V8 and leaning six cars automatic trans. cars I worked on, including the street hemi cars, had 5/16 O.D. lines on the tranny up to the radiator heaters
I'm not sure what size lines my 2006 Ram 3500 4WD truck with the factory towing packages has for line I.D. or O.D. sizes Maybe I should go check My first Dodge CTD Ram 2500 24 valve (1998 1/2) had the factory towing package on it, I added a tranny temp gauge and found out that it should have had a thermostat to the external tranny cooler, the trans temps never got above 140F when not towing, summer or winter in the CA Mojave desert
I haven't added a gauge to this truck due to not wanting to worry about the trans temps

I stand corrected on the passenger car lines - yes, 5/16".

Since my car is outside and it’s snowed about 5” this AM and it’s -9 does anyone have the ability to measure from the trans to in front of the radiator? I need to know line length so I can order this stuff. I’m using aeroquip startlite line and fittings.

I'll be in the shop shortly and I can measure my Dart if needed.


53" from the rear fitting to the face of the radiator support in a straight line.

What year and body style?
The Plymouths have two inch longer wheel base so they may have different length lines also
OOPS I just reread the first post

Thanks Justinp61.

Cab_burge, 4 extra inches wouldn’t have hurt the pocket book 😬

I was thinking that someone priorly said that the ID somewhere in the internal cooling passages inside the trans makes going to a 3/8 line a moot point. If this is bogus I will for sure tap to the next larger size as those brass 1/8 NPT/inverted flare fittings are available in the next larger size along with useing 3/8 line.

Going to larger lines does add flow. All the internal geartrain lube passages are the same size between the 42/44/46/47/48 RE-RH.

All the three speeds are 1 to 1 running down the road. The over drives have planetary action in the OD unit in 4th gear. That's why they need larger lines than the 3 speeds.

^^^ noted, thank you. On my next one I will tap/go to 3/8 line

What trans. cooler are you guys running? I'd like to Drag Week my car in the next year or so.

I'm looking at this one...
Derale 13900 Derale Electra-Cool Remote Fluid Coolers 13900

people have said that the "stacked plate" types transfer more heat

I have a stacked plate cooler. Does it matter which position the cooler lines are mounted ?

No, just mount it in the most convenient appropriate position for the easiest/shortest hose routing.

I run a B&M stacked plate cooler, 8" 4500 converter, no fan, and nothing through the radiator. I have done 5 drag weeks with my road weight at about 4200lbs with passenger and gear. Now I do not have a temp gauge but I have run the same fluid for at least 8 years and it still looks good. The few times I have hit the trans cooler with a temp gun it has been 150-180* not that its much of an indication of fluid temp but I didn't think that was bad.

Bad fish, where did you mount your cooler?

It is mounted down low in front of the radiator.

I use a trans cooler I bought from Advance Auto Parts about 20 years ago. Mounted in front the radiator. Works great, lol.

That’s what I have but I want it plumbed with AN and braided line so I can save my stock lines for a later project.

I have -6AN lines on it w/ a hose clamp. Backyard yes, but it works.

Jbody, is the transmission side or hose side a 45 degree fitting? I can’t find a 45 degree -6AN to 1/8” NPT fitting anywhere

Fragola has the -6AN to 1/8" NPT fittings with 45 degree angle
https://www.summitracing.com/parts/fra-482362-bl/overview/

I used the straight adapter fittings and the angled hose ends instead of angled fittings,

^ fitting right out of the trans. Local welding shop has Redhorse stuff in stock. Bought one there.

C&R out of Aussi makes a nice 10x11 plate type cooler with -6 fittings welded on to it. I was having issues with the trans temp staying too high, especially if running two classes. I had one of those "log" type heat exchangers under the front bumper on my car. I retained that, but also went with a new crossflow rad that had the trans cooler mounted in the tank. That took care of my prob. I have the C&R cooler, but so far it's just wall art.

Thanks Jbody and RTSE4ME